From 9b7a7c42ba5e90891323a497e159b92e27cb746f Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Fri, 22 Aug 2025 08:13:06 +0300
Subject: [PATCH 01/46] ADBDEV-7890

---
 helper/restore_helper.go           | 27 ++++++++++++++++++++++-----
 plugins/example_plugin.bash        | 20 ++++++++++++++++++++
 plugins/example_plugin_config.yaml |  3 ++-
 3 files changed, 44 insertions(+), 6 deletions(-)

diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index a4c5120fe..d11a1ec4d 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -40,6 +40,14 @@ var (
 	contentRE   *regexp.Regexp
 )
 
+type DiscardError struct {
+	what string
+}
+
+func (e DiscardError) Error() string {
+	return e.what
+}
+
 /* IRestoreReader interface to wrap the underlying reader.
  * getReaderType() identifies how the reader can be used
  * SEEKABLE uses seekReader. Used when restoring from uncompressed data with filters from local filesystem
@@ -108,8 +116,20 @@ func (r *RestoreReader) copyData(num int64) (int64, error) {
 	switch r.readerType {
 	case SEEKABLE:
 		bytesRead, err = io.CopyN(writer, r.seekReader, num)
-	case NONSEEKABLE, SUBSET:
+	case NONSEEKABLE:
 		bytesRead, err = io.CopyN(writer, r.bufReader, num)
+	case SUBSET:
+		bytesRead, err = io.CopyN(writer, r.bufReader, num)
+		if err != nil {
+			if err != io.EOF {
+				bytesLeftToRead := num - bytesRead
+				bytesDiscard, errDiscard := io.CopyN(io.Discard, r.bufReader, bytesLeftToRead)
+				bytesRead += bytesDiscard
+				
+				err = DiscardError {errDiscard.Error()}
+				//Что делать в случае критичных ошибок?
+			}
+		}
 	}
 	return bytesRead, err
 }
@@ -612,10 +632,6 @@ func getSubsetFlag(fileToRead string, pluginConfig *utils.PluginConfig) bool {
 	if !pluginConfig.CanRestoreSubset() {
 		return false
 	}
-	// Helper's option does not allow to use subset
-	if !*isFiltered || *onErrorContinue {
-		return false
-	}
 	// Restore subset and compression does not allow together
 	if strings.HasSuffix(fileToRead, ".gz") || strings.HasSuffix(fileToRead, ".zst") {
 		return false
@@ -663,6 +679,7 @@ func startRestorePluginCommand(fileToRead string, objToc *toc.SegmentTOC, oidLis
 		return nil, nil, false, err
 	}
 	cmdStr := ""
+	logVerbose("sokolov111", *isFiltered, *onErrorContinue, objToc, getSubsetFlag(fileToRead, pluginConfig))
 	if objToc != nil && getSubsetFlag(fileToRead, pluginConfig) {
 		offsetsFile, _ := ioutil.TempFile("/tmp", "gprestore_offsets_")
 		defer func() {
diff --git a/plugins/example_plugin.bash b/plugins/example_plugin.bash
index 302d5d6c8..9683f4691 100755
--- a/plugins/example_plugin.bash
+++ b/plugins/example_plugin.bash
@@ -89,6 +89,26 @@ restore_data() {
 	cat /tmp/plugin_dest/$timestamp_day_dir/$timestamp_dir/$filename
 }
 
+restore_data_subset() {
+  echo "restore_data_subset $1 $2 $3" >> /tmp/plugin_out.txt
+  filename=`basename "$2"`
+  timestamp_dir=`basename $(dirname "$2")`
+  timestamp_day_dir=${timestamp_dir%??????}
+  if [ -e "/tmp/GPBACKUP_PLUGIN_LOG_TO_STDERR" ] ; then
+    echo 'Some plugin warning' >&2
+  elif [ -e "/tmp/GPBACKUP_PLUGIN_DIE" -a "$GPBACKUP_PLUGIN_DIE_ON_OID" = "" ] ; then
+    exit 1
+  elif [[ -e "/tmp/GPBACKUP_PLUGIN_DIE" && "$filename" == *"$GPBACKUP_PLUGIN_DIE_ON_OID"* ]] ; then
+    # sleep a while for test purposes - to let gprestore start COPY commands
+    sleep 5
+    exit 1
+  fi
+	/home/keremet/arenadata/tasks/7890_handle_table_restore_errors_during_subset_restore/restore_data_subset /tmp/plugin_dest/$timestamp_day_dir/$timestamp_dir/$filename $3
+}
+
+
+
+
 delete_backup() {
   echo "delete_backup $1 $2" >> /tmp/plugin_out.txt
   timestamp_day_dir=${2%??????}
diff --git a/plugins/example_plugin_config.yaml b/plugins/example_plugin_config.yaml
index 89deab6a7..bad10e64b 100644
--- a/plugins/example_plugin_config.yaml
+++ b/plugins/example_plugin_config.yaml
@@ -1,3 +1,4 @@
-executablepath: $GOPATH/src/github.com/greenplum-db/gpbackup/plugins/example_plugin.bash
+executablepath: /home/keremet/compile/gpbackup/plugins/example_plugin.bash
 options:
   password: unknown
+  restore_subset: on

From f52c130b38b80c473ca95d893a1ed70ed76d409b Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Thu, 28 Aug 2025 16:26:28 +0300
Subject: [PATCH 02/46] Error handling

---
 helper/restore_helper.go           | 49 +++++++++++++++++++-----------
 plugins/example_plugin.bash        | 20 ------------
 plugins/example_plugin_config.yaml |  3 +-
 3 files changed, 33 insertions(+), 39 deletions(-)

diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index d11a1ec4d..634df55cd 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -40,13 +40,7 @@ var (
 	contentRE   *regexp.Regexp
 )
 
-type DiscardError struct {
-	what string
-}
-
-func (e DiscardError) Error() string {
-	return e.what
-}
+var discardError = errors.New("helper: discard error")
 
 /* IRestoreReader interface to wrap the underlying reader.
  * getReaderType() identifies how the reader can be used
@@ -62,6 +56,7 @@ type IRestoreReader interface {
 	copyAllData() (int64, error)
 	closeFileHandle()
 	getReaderType() ReaderType
+	discardData(num int64) (int64, error)
 }
 
 type RestoreReader struct {
@@ -110,6 +105,16 @@ func (r *RestoreReader) positionReader(pos uint64, oid int) error {
 	return nil
 }
 
+func (r *RestoreReader) discardData(num int64) (int64, error) {
+	if (r.readerType == SUBSET) {
+		n, err := io.CopyN(io.Discard, r.bufReader, num)
+		logVerbose(fmt.Sprintf("%d bytes to discard, discarded %d bytes", num, n))
+		return n, err
+	}
+
+	return 0, nil
+}
+
 func (r *RestoreReader) copyData(num int64) (int64, error) {
 	var bytesRead int64
 	var err error
@@ -120,14 +125,15 @@ func (r *RestoreReader) copyData(num int64) (int64, error) {
 		bytesRead, err = io.CopyN(writer, r.bufReader, num)
 	case SUBSET:
 		bytesRead, err = io.CopyN(writer, r.bufReader, num)
-		if err != nil {
-			if err != io.EOF {
-				bytesLeftToRead := num - bytesRead
-				bytesDiscard, errDiscard := io.CopyN(io.Discard, r.bufReader, bytesLeftToRead)
-				bytesRead += bytesDiscard
-				
-				err = DiscardError {errDiscard.Error()}
-				//Что делать в случае критичных ошибок?
+		if err != nil && err != io.EOF && *onErrorContinue {
+			bytesDiscard, errDiscard := r.discardData(num - bytesRead)
+			bytesRead += bytesDiscard
+			if errDiscard != nil {
+				if errDiscard == io.EOF {
+					err = errDiscard
+				} else {
+					err = errors.Wrap(discardError, errDiscard.Error())
+				}
 			}
 		}
 	}
@@ -371,6 +377,16 @@ func doRestoreAgentInternal(restoreHelper IRestoreHelper) error {
 						logWarn(fmt.Sprintf("Oid %d, Batch %d: Skip file discovered, skipping this relation.", tableOid, batchNum))
 						err = nil
 						skipOid = tableOid
+						if *singleDataFile {
+							_, errDiscard := readers[contentToRestore].discardData(int64(end[contentToRestore] - start[contentToRestore]))
+							if errDiscard != nil {
+								if errDiscard == io.EOF {
+									err = errDiscard
+								} else {
+									err = errors.Wrap(discardError, errDiscard.Error())
+								}
+							}
+						}
 						/* Close up to *copyQueue files with this tableOid */
 						for idx := 0; idx < *copyQueue; idx++ {
 							batchToDelete := batchNum + idx
@@ -465,7 +481,7 @@ func doRestoreAgentInternal(restoreHelper IRestoreHelper) error {
 
 		if err != nil {
 			logError(fmt.Sprintf("Oid %d, Batch %d: Error encountered: %v", tableOid, batchNum, err))
-			if *onErrorContinue {
+			if *onErrorContinue && !errors.Is(err, io.EOF) && !errors.Is(err, discardError) {
 				lastError = err
 				err = nil
 				continue
@@ -679,7 +695,6 @@ func startRestorePluginCommand(fileToRead string, objToc *toc.SegmentTOC, oidLis
 		return nil, nil, false, err
 	}
 	cmdStr := ""
-	logVerbose("sokolov111", *isFiltered, *onErrorContinue, objToc, getSubsetFlag(fileToRead, pluginConfig))
 	if objToc != nil && getSubsetFlag(fileToRead, pluginConfig) {
 		offsetsFile, _ := ioutil.TempFile("/tmp", "gprestore_offsets_")
 		defer func() {
diff --git a/plugins/example_plugin.bash b/plugins/example_plugin.bash
index 9683f4691..302d5d6c8 100755
--- a/plugins/example_plugin.bash
+++ b/plugins/example_plugin.bash
@@ -89,26 +89,6 @@ restore_data() {
 	cat /tmp/plugin_dest/$timestamp_day_dir/$timestamp_dir/$filename
 }
 
-restore_data_subset() {
-  echo "restore_data_subset $1 $2 $3" >> /tmp/plugin_out.txt
-  filename=`basename "$2"`
-  timestamp_dir=`basename $(dirname "$2")`
-  timestamp_day_dir=${timestamp_dir%??????}
-  if [ -e "/tmp/GPBACKUP_PLUGIN_LOG_TO_STDERR" ] ; then
-    echo 'Some plugin warning' >&2
-  elif [ -e "/tmp/GPBACKUP_PLUGIN_DIE" -a "$GPBACKUP_PLUGIN_DIE_ON_OID" = "" ] ; then
-    exit 1
-  elif [[ -e "/tmp/GPBACKUP_PLUGIN_DIE" && "$filename" == *"$GPBACKUP_PLUGIN_DIE_ON_OID"* ]] ; then
-    # sleep a while for test purposes - to let gprestore start COPY commands
-    sleep 5
-    exit 1
-  fi
-	/home/keremet/arenadata/tasks/7890_handle_table_restore_errors_during_subset_restore/restore_data_subset /tmp/plugin_dest/$timestamp_day_dir/$timestamp_dir/$filename $3
-}
-
-
-
-
 delete_backup() {
   echo "delete_backup $1 $2" >> /tmp/plugin_out.txt
   timestamp_day_dir=${2%??????}
diff --git a/plugins/example_plugin_config.yaml b/plugins/example_plugin_config.yaml
index bad10e64b..89deab6a7 100644
--- a/plugins/example_plugin_config.yaml
+++ b/plugins/example_plugin_config.yaml
@@ -1,4 +1,3 @@
-executablepath: /home/keremet/compile/gpbackup/plugins/example_plugin.bash
+executablepath: $GOPATH/src/github.com/greenplum-db/gpbackup/plugins/example_plugin.bash
 options:
   password: unknown
-  restore_subset: on

From 0b3fe62330dd83afe0d18ce2bb3b0f3c3e2cb687 Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Fri, 29 Aug 2025 08:52:26 +0300
Subject: [PATCH 03/46] Fix test

---
 helper/helper_test.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/helper/helper_test.go b/helper/helper_test.go
index f9e0d3b83..0d8be00c5 100644
--- a/helper/helper_test.go
+++ b/helper/helper_test.go
@@ -48,6 +48,10 @@ func (r *restoreReaderTestImpl) getReaderType() ReaderType {
 	return "nil"
 }
 
+func (r *restoreReaderTestImpl) discardData(num int64) (int64, error) {
+	return num, nil
+}
+
 type helperTestStep struct {
 	restorePipeWriterArgExpect string
 	restorePipeWriterResult    bool

From 5ca11b709c1563b9c27801a8116177727f692d99 Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Fri, 29 Aug 2025 16:45:51 +0300
Subject: [PATCH 04/46] Fix test

---
 helper/helper_test.go    |  2 +-
 helper/restore_helper.go | 14 ++++++++------
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/helper/helper_test.go b/helper/helper_test.go
index 0d8be00c5..f499a4c76 100644
--- a/helper/helper_test.go
+++ b/helper/helper_test.go
@@ -247,7 +247,7 @@ var _ = Describe("helper tests", func() {
 			pluginConfig.Options["restore_subset"] = "on"
 			*onErrorContinue = true
 			isSubset = getSubsetFlag(fileToRead, &pluginConfig)
-			Expect(isSubset).To(Equal(false))
+			Expect(isSubset).To(Equal(true))
 		})
 		It("when restore_subset is off, --on-error-continue is false, compression \"gz\" is used", func() {
 			pluginConfig.Options["restore_subset"] = "off"
diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index 634df55cd..d4bea4e05 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -378,12 +378,14 @@ func doRestoreAgentInternal(restoreHelper IRestoreHelper) error {
 						err = nil
 						skipOid = tableOid
 						if *singleDataFile {
-							_, errDiscard := readers[contentToRestore].discardData(int64(end[contentToRestore] - start[contentToRestore]))
-							if errDiscard != nil {
-								if errDiscard == io.EOF {
-									err = errDiscard
-								} else {
-									err = errors.Wrap(discardError, errDiscard.Error())
+							if readers[contentToRestore] != nil {
+								_, errDiscard := readers[contentToRestore].discardData(int64(end[contentToRestore] - start[contentToRestore]))
+								if errDiscard != nil {
+									if errDiscard == io.EOF {
+										err = errDiscard
+									} else {
+										err = errors.Wrap(discardError, errDiscard.Error())
+									}
 								}
 							}
 						}

From e2fab0aa9f3b765491afd1fb7288d0ddf7237506 Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Fri, 29 Aug 2025 16:58:20 +0300
Subject: [PATCH 05/46] Decrease indentation

---
 helper/restore_helper.go | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index d4bea4e05..c0620d7be 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -377,15 +377,14 @@ func doRestoreAgentInternal(restoreHelper IRestoreHelper) error {
 						logWarn(fmt.Sprintf("Oid %d, Batch %d: Skip file discovered, skipping this relation.", tableOid, batchNum))
 						err = nil
 						skipOid = tableOid
-						if *singleDataFile {
-							if readers[contentToRestore] != nil {
-								_, errDiscard := readers[contentToRestore].discardData(int64(end[contentToRestore] - start[contentToRestore]))
-								if errDiscard != nil {
-									if errDiscard == io.EOF {
-										err = errDiscard
-									} else {
-										err = errors.Wrap(discardError, errDiscard.Error())
-									}
+						if *singleDataFile && readers[contentToRestore] != nil {
+							bytesToDiscard := int64(end[contentToRestore] - start[contentToRestore])
+							_, errDiscard := readers[contentToRestore].discardData(bytesToDiscard)
+							if errDiscard != nil {
+								if errDiscard == io.EOF {
+									err = errDiscard
+								} else {
+									err = errors.Wrap(discardError, errDiscard.Error())
 								}
 							}
 						}

From 5c4db1a82cd7cd268f0567fc18bccc5d822906ba Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Mon, 1 Sep 2025 10:55:01 +0300
Subject: [PATCH 06/46] Revert condition

---
 helper/restore_helper.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index c0620d7be..21b9d740a 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -649,6 +649,10 @@ func getSubsetFlag(fileToRead string, pluginConfig *utils.PluginConfig) bool {
 	if !pluginConfig.CanRestoreSubset() {
 		return false
 	}
+	// Helper's option does not allow to use subset
+	if !*isFiltered {
+		return false
+	}
 	// Restore subset and compression does not allow together
 	if strings.HasSuffix(fileToRead, ".gz") || strings.HasSuffix(fileToRead, ".zst") {
 		return false

From 90d5469f1a2ad8e96595815b0f8b0fd557f99053 Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Mon, 1 Sep 2025 16:38:52 +0300
Subject: [PATCH 07/46] Add tests

---
 helper/helper_test.go | 106 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 106 insertions(+)

diff --git a/helper/helper_test.go b/helper/helper_test.go
index f499a4c76..f98cdd1e2 100644
--- a/helper/helper_test.go
+++ b/helper/helper_test.go
@@ -3,6 +3,7 @@ package helper
 import (
 	"bufio"
 	"fmt"
+	"io"
 	"os"
 
 	"github.com/greenplum-db/gpbackup/utils"
@@ -202,6 +203,47 @@ func (pt *testPluginCmd) Wait() error {
 func (pt *testPluginCmd) errLog() {
 }
 
+type limitReader struct {
+	rem int
+	err error
+}
+
+func (r *limitReader) Read(p []byte) (n int, err error) {
+	if r.rem <= 0 {
+		return 0, r.err
+	}
+
+	if len(p) > r.rem {
+		p = p[0:r.rem]
+	}
+
+	n = len(p)
+	for i := 0; i < n; i++ {
+		p[i] = 1
+	}
+	r.rem -= n
+	return
+}
+
+type limitWriter struct {
+	rem int
+}
+
+func (w *limitWriter) Write(p []byte) (n int, err error) {
+	if w.rem < len(p) {
+		n = w.rem
+	} else {
+		n = len(p)
+	}
+
+	if w.rem == 0 {
+		err = io.ErrShortWrite
+	}
+
+	w.rem -= n
+	return
+}
+
 var _ = Describe("helper tests", func() {
 	var pluginConfig utils.PluginConfig
 	var isSubset bool
@@ -508,6 +550,70 @@ var _ = Describe("helper tests", func() {
 			Expect(err).To(HaveOccurred())
 			Expect(err.Error()).To(Equal(msg))
 		})
+		It("CopyData, readerType is SUBSET. Normal completion", func() {
+			writer = bufio.NewWriterSize(&limitWriter{100}, 5)
+
+			test_reader := RestoreReader{
+				readerType: SUBSET,
+				bufReader:  bufio.NewReader(&limitReader{100, io.EOF}),
+			}
+
+			bytesRead, err := test_reader.copyData(18)
+			Expect(bytesRead).To(Equal(int64(18)))
+			Expect(err).ToNot(HaveOccurred())
+		})
+		It("CopyData, readerType is SUBSET. Error on write", func() {
+			*onErrorContinue = true
+			writer = bufio.NewWriterSize(&limitWriter{7}, 5)
+
+			test_reader := RestoreReader{
+				readerType: SUBSET,
+				bufReader:  bufio.NewReader(&limitReader{100, io.EOF}),
+			}
+
+			bytesRead, err := test_reader.copyData(18)
+			Expect(bytesRead).To(Equal(int64(18)))
+			Expect(err).To(HaveOccurred())
+		})
+		It("CopyData, readerType is SUBSET. EOF", func() {
+			*onErrorContinue = true
+			writer = bufio.NewWriterSize(&limitWriter{100}, 5)
+
+			test_reader := RestoreReader{
+				readerType: SUBSET,
+				bufReader:  bufio.NewReader(&limitReader{25, io.EOF}),
+			}
+
+			bytesRead, err := test_reader.copyData(30)
+			Expect(bytesRead).To(Equal(int64(25)))
+			Expect(err).To(Equal(io.EOF))
+		})
+		It("CopyData, readerType is SUBSET. Error on write and EOF", func() {
+			*onErrorContinue = true
+			writer = bufio.NewWriterSize(&limitWriter{7}, 5)
+
+			test_reader := RestoreReader{
+				readerType: SUBSET,
+				bufReader:  bufio.NewReader(&limitReader{25, io.EOF}),
+			}
+
+			bytesRead, err := test_reader.copyData(30)
+			Expect(bytesRead).To(Equal(int64(25)))
+			Expect(err).To(Equal(io.EOF))
+		})
+		It("CopyData, readerType is SUBSET. Error on write and on read", func() {
+			*onErrorContinue = true
+			writer = bufio.NewWriterSize(&limitWriter{7}, 5)
+
+			test_reader := RestoreReader{
+				readerType: SUBSET,
+				bufReader:  bufio.NewReader(&limitReader{25, io.ErrNoProgress}),
+			}
+
+			bytesRead, err := test_reader.copyData(30)
+			Expect(bytesRead).To(Equal(int64(25)))
+			Expect(errors.Is(err, discardError)).To(Equal(true))
+		})
 	})
 })
 

From 87e6f24bd38ca6b60eb683651ba0ea850137a976 Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Tue, 2 Sep 2025 17:10:48 +0300
Subject: [PATCH 08/46] skipoid test

---
 helper/helper_test.go | 31 ++++++++++++++++++++++++++++---
 1 file changed, 28 insertions(+), 3 deletions(-)

diff --git a/helper/helper_test.go b/helper/helper_test.go
index f98cdd1e2..b03069ce2 100644
--- a/helper/helper_test.go
+++ b/helper/helper_test.go
@@ -19,6 +19,7 @@ import (
 var (
 	testDir     = "/tmp/helper_test/20180101/20180101010101"
 	testTocFile = fmt.Sprintf("%s/test_toc.yaml", testDir)
+	discarded int64
 )
 
 type restoreReaderTestImpl struct {
@@ -50,6 +51,7 @@ func (r *restoreReaderTestImpl) getReaderType() ReaderType {
 }
 
 func (r *restoreReaderTestImpl) discardData(num int64) (int64, error) {
+	discarded += num
 	return num, nil
 }
 
@@ -462,6 +464,29 @@ var _ = Describe("helper tests", func() {
 			err := doRestoreAgentInternal(helper)
 			Expect(err).To(BeNil())
 		})
+		It("discard data if skip file is discovered with single datafile", func() {
+			*singleDataFile = true
+			*isResizeRestore = false
+			*tocFile = testTocFile
+
+			writeTestTOC(testTocFile)
+			defer func() {
+				_ = os.Remove(*tocFile)
+			}()
+
+			oidBatch := []oidWithBatch{
+				{1 /* The first oid from TOC */, 0}, 
+			}
+
+			expectedScenario := []helperTestStep{
+				{"mock_1_0", false, 1, true, "Can not open pipe for table 1, check_skip_file shall called, skip file exists"},
+			}
+
+			helper := newHelperTest(oidBatch, expectedScenario)
+			err := doRestoreAgentInternal(helper)
+			Expect(err).To(BeNil())
+			Expect(discarded).To(Equal(int64(18)))
+		})
 		It("calls Wait in waitForPlugin doRestoreAgent for single data file", func() {
 			*singleDataFile = true
 			*isResizeRestore = false
@@ -621,13 +646,13 @@ func writeTestTOC(tocFile string) {
 	// Write test TOC. We are not going to read data using it, so dataLength is a random number
 	dataLength := 100
 	customTOC := fmt.Sprintf(`dataentries:
-1:
+  1:
     startbyte: 0
     endbyte: 18
-2:
+  2:
     startbyte: 18
     endbyte: %[1]d
-3:
+  3:
     startbyte: %[1]d
     endbyte: %d
 `, dataLength+18, dataLength+18+18)

From bbae9baf20d3aed284c8c8380638bdf391d391b6 Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Wed, 3 Sep 2025 10:46:08 +0300
Subject: [PATCH 09/46] Remove parenthesis

---
 helper/restore_helper.go | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index 21b9d740a..795cd2c00 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -106,7 +106,7 @@ func (r *RestoreReader) positionReader(pos uint64, oid int) error {
 }
 
 func (r *RestoreReader) discardData(num int64) (int64, error) {
-	if (r.readerType == SUBSET) {
+	if r.readerType == SUBSET {
 		n, err := io.CopyN(io.Discard, r.bufReader, num)
 		logVerbose(fmt.Sprintf("%d bytes to discard, discarded %d bytes", num, n))
 		return n, err
@@ -266,11 +266,14 @@ func doRestoreAgentInternal(restoreHelper IRestoreHelper) error {
 				break
 			}
 			tocFileForContent := replaceContentInFilename(*tocFile, contentToRestore)
+			logWarn("\n\n!!!!!tocFileForContent = ", tocFileForContent)
 			segmentTOC[contentToRestore] = toc.NewSegmentTOC(tocFileForContent)
+			logWarn("\n\n!!!!!tocFileForContent = ", segmentTOC[contentToRestore])
 			tocEntries[contentToRestore] = segmentTOC[contentToRestore].DataEntries
 
 			filename := replaceContentInFilename(*dataFile, contentToRestore)
 			readers[contentToRestore], err = restoreHelper.getRestoreDataReader(filename, segmentTOC[contentToRestore], oidList)
+			logWarn("\n\n!!!!!readers[contentToRestore] = ", readers[contentToRestore])
 			if readers[contentToRestore] != nil {
 				// NOTE: If we reach here with batches > 1, there will be
 				// *origSize / *destSize (N old segments / N new segments)
@@ -360,11 +363,14 @@ func doRestoreAgentInternal(restoreHelper IRestoreHelper) error {
 			}
 		}
 
+		logWarn("\n\n!!!!! 2 readers[contentToRestore] = ", readers[contentToRestore], tocEntries)
 		logInfo(fmt.Sprintf("Oid %d, Batch %d: Opening pipe %s", tableOid, batchNum, currentPipe))
 		for {
 			writer, writeHandle, err = restoreHelper.getRestorePipeWriter(currentPipe)
+			logWarn("\n\n!!!!! 3 writer, writeHandle, err = ", writer, writeHandle, err)
 			if err != nil {
 				if errors.Is(err, unix.ENXIO) {
+					logWarn("\n\n!!!!! 4 writer, writeHandle, err = ", writer, writeHandle, err)
 					// COPY (the pipe reader) has not tried to access the pipe yet so our restore_helper
 					// process will get ENXIO error on its nonblocking open call on the pipe. We loop in
 					// here while looking to see if gprestore has created a skip file for this restore entry.
@@ -374,7 +380,8 @@ func doRestoreAgentInternal(restoreHelper IRestoreHelper) error {
 					// not contain a database connection so the version should be passed through the helper
 					// invocation from gprestore (e.g. create a --db-version flag option).
 					if *onErrorContinue && restoreHelper.checkForSkipFile(*pipeFile, tableOid) {
-						logWarn(fmt.Sprintf("Oid %d, Batch %d: Skip file discovered, skipping this relation.", tableOid, batchNum))
+						logWarn(fmt.Sprintf("Oid %d, Batch %d: Skip file discovered, skipping this relation.", tableOid, batchNum), *singleDataFile, readers[contentToRestore])
+						logWarn("", end[contentToRestore], start[contentToRestore], contentToRestore)
 						err = nil
 						skipOid = tableOid
 						if *singleDataFile && readers[contentToRestore] != nil {

From 663f7f7b9145b197572b6d7b8dcbc78895b19adb Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Wed, 3 Sep 2025 11:26:28 +0300
Subject: [PATCH 10/46] Deduplication

---
 helper/restore_helper.go | 23 +++++++++--------------
 1 file changed, 9 insertions(+), 14 deletions(-)

diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index 795cd2c00..75321be6a 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -108,7 +108,13 @@ func (r *RestoreReader) positionReader(pos uint64, oid int) error {
 func (r *RestoreReader) discardData(num int64) (int64, error) {
 	if r.readerType == SUBSET {
 		n, err := io.CopyN(io.Discard, r.bufReader, num)
-		logVerbose(fmt.Sprintf("%d bytes to discard, discarded %d bytes", num, n))
+		if err != nil {
+			logVerbose(fmt.Sprintf("%d bytes to discard", n))
+			if err != io.EOF {
+				err = errors.Wrap(discardError, err.Error())
+			}
+		}
+		logVerbose(fmt.Sprintf("%discarded %d bytes", n))
 		return n, err
 	}
 
@@ -129,11 +135,7 @@ func (r *RestoreReader) copyData(num int64) (int64, error) {
 			bytesDiscard, errDiscard := r.discardData(num - bytesRead)
 			bytesRead += bytesDiscard
 			if errDiscard != nil {
-				if errDiscard == io.EOF {
-					err = errDiscard
-				} else {
-					err = errors.Wrap(discardError, errDiscard.Error())
-				}
+				err = errDiscard
 			}
 		}
 	}
@@ -386,14 +388,7 @@ func doRestoreAgentInternal(restoreHelper IRestoreHelper) error {
 						skipOid = tableOid
 						if *singleDataFile && readers[contentToRestore] != nil {
 							bytesToDiscard := int64(end[contentToRestore] - start[contentToRestore])
-							_, errDiscard := readers[contentToRestore].discardData(bytesToDiscard)
-							if errDiscard != nil {
-								if errDiscard == io.EOF {
-									err = errDiscard
-								} else {
-									err = errors.Wrap(discardError, errDiscard.Error())
-								}
-							}
+							_, err = readers[contentToRestore].discardData(bytesToDiscard)
 						}
 						/* Close up to *copyQueue files with this tableOid */
 						for idx := 0; idx < *copyQueue; idx++ {

From c9acd36bd84181fe8ebc7761f26d27ec3c7f6ba6 Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Wed, 3 Sep 2025 11:35:54 +0300
Subject: [PATCH 11/46] Fix

---
 helper/restore_helper.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index 75321be6a..5e11edd73 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -114,7 +114,7 @@ func (r *RestoreReader) discardData(num int64) (int64, error) {
 				err = errors.Wrap(discardError, err.Error())
 			}
 		}
-		logVerbose(fmt.Sprintf("%discarded %d bytes", n))
+		logVerbose(fmt.Sprintf("discarded %d bytes", n))
 		return n, err
 	}
 

From 4d66f3e09a35d769d218492780b8035a51aae787 Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Wed, 3 Sep 2025 11:38:07 +0300
Subject: [PATCH 12/46] Revert "Remove parenthesis"

This reverts commit bbae9baf20d3aed284c8c8380638bdf391d391b6.
---
 helper/restore_helper.go | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index 5e11edd73..5602d384d 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -106,7 +106,7 @@ func (r *RestoreReader) positionReader(pos uint64, oid int) error {
 }
 
 func (r *RestoreReader) discardData(num int64) (int64, error) {
-	if r.readerType == SUBSET {
+	if (r.readerType == SUBSET) {
 		n, err := io.CopyN(io.Discard, r.bufReader, num)
 		if err != nil {
 			logVerbose(fmt.Sprintf("%d bytes to discard", n))
@@ -268,14 +268,11 @@ func doRestoreAgentInternal(restoreHelper IRestoreHelper) error {
 				break
 			}
 			tocFileForContent := replaceContentInFilename(*tocFile, contentToRestore)
-			logWarn("\n\n!!!!!tocFileForContent = ", tocFileForContent)
 			segmentTOC[contentToRestore] = toc.NewSegmentTOC(tocFileForContent)
-			logWarn("\n\n!!!!!tocFileForContent = ", segmentTOC[contentToRestore])
 			tocEntries[contentToRestore] = segmentTOC[contentToRestore].DataEntries
 
 			filename := replaceContentInFilename(*dataFile, contentToRestore)
 			readers[contentToRestore], err = restoreHelper.getRestoreDataReader(filename, segmentTOC[contentToRestore], oidList)
-			logWarn("\n\n!!!!!readers[contentToRestore] = ", readers[contentToRestore])
 			if readers[contentToRestore] != nil {
 				// NOTE: If we reach here with batches > 1, there will be
 				// *origSize / *destSize (N old segments / N new segments)
@@ -365,14 +362,11 @@ func doRestoreAgentInternal(restoreHelper IRestoreHelper) error {
 			}
 		}
 
-		logWarn("\n\n!!!!! 2 readers[contentToRestore] = ", readers[contentToRestore], tocEntries)
 		logInfo(fmt.Sprintf("Oid %d, Batch %d: Opening pipe %s", tableOid, batchNum, currentPipe))
 		for {
 			writer, writeHandle, err = restoreHelper.getRestorePipeWriter(currentPipe)
-			logWarn("\n\n!!!!! 3 writer, writeHandle, err = ", writer, writeHandle, err)
 			if err != nil {
 				if errors.Is(err, unix.ENXIO) {
-					logWarn("\n\n!!!!! 4 writer, writeHandle, err = ", writer, writeHandle, err)
 					// COPY (the pipe reader) has not tried to access the pipe yet so our restore_helper
 					// process will get ENXIO error on its nonblocking open call on the pipe. We loop in
 					// here while looking to see if gprestore has created a skip file for this restore entry.
@@ -382,8 +376,7 @@ func doRestoreAgentInternal(restoreHelper IRestoreHelper) error {
 					// not contain a database connection so the version should be passed through the helper
 					// invocation from gprestore (e.g. create a --db-version flag option).
 					if *onErrorContinue && restoreHelper.checkForSkipFile(*pipeFile, tableOid) {
-						logWarn(fmt.Sprintf("Oid %d, Batch %d: Skip file discovered, skipping this relation.", tableOid, batchNum), *singleDataFile, readers[contentToRestore])
-						logWarn("", end[contentToRestore], start[contentToRestore], contentToRestore)
+						logWarn(fmt.Sprintf("Oid %d, Batch %d: Skip file discovered, skipping this relation.", tableOid, batchNum))
 						err = nil
 						skipOid = tableOid
 						if *singleDataFile && readers[contentToRestore] != nil {

From 68aa2ee8a6f45be010cade4305034f59bb1b9761 Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Wed, 3 Sep 2025 11:38:56 +0300
Subject: [PATCH 13/46] Remove parenthesis

---
 helper/restore_helper.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index 5602d384d..c012924c7 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -106,7 +106,7 @@ func (r *RestoreReader) positionReader(pos uint64, oid int) error {
 }
 
 func (r *RestoreReader) discardData(num int64) (int64, error) {
-	if (r.readerType == SUBSET) {
+	if r.readerType == SUBSET {
 		n, err := io.CopyN(io.Discard, r.bufReader, num)
 		if err != nil {
 			logVerbose(fmt.Sprintf("%d bytes to discard", n))

From fe9fc5a77c4289cbe9a0a2ab39639a494f96be5f Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Wed, 3 Sep 2025 13:41:57 +0300
Subject: [PATCH 14/46] Assert

---
 helper/restore_helper.go | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index c012924c7..a2e3edf1d 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -106,19 +106,19 @@ func (r *RestoreReader) positionReader(pos uint64, oid int) error {
 }
 
 func (r *RestoreReader) discardData(num int64) (int64, error) {
-	if r.readerType == SUBSET {
-		n, err := io.CopyN(io.Discard, r.bufReader, num)
-		if err != nil {
-			logVerbose(fmt.Sprintf("%d bytes to discard", n))
-			if err != io.EOF {
-				err = errors.Wrap(discardError, err.Error())
-			}
-		}
-		logVerbose(fmt.Sprintf("discarded %d bytes", n))
-		return n, err
+	if r.readerType != SUBSET {
+		panic("discardData should be called for readerType == SUBSET only")
 	}
 
-	return 0, nil
+	n, err := io.CopyN(io.Discard, r.bufReader, num)
+	if err != nil {
+		logVerbose(fmt.Sprintf("%d bytes to discard", n))
+		if err != io.EOF {
+			err = errors.Wrap(discardError, err.Error())
+		}
+	}
+	logVerbose(fmt.Sprintf("discarded %d bytes", n))
+	return n, err
 }
 
 func (r *RestoreReader) copyData(num int64) (int64, error) {
@@ -379,7 +379,7 @@ func doRestoreAgentInternal(restoreHelper IRestoreHelper) error {
 						logWarn(fmt.Sprintf("Oid %d, Batch %d: Skip file discovered, skipping this relation.", tableOid, batchNum))
 						err = nil
 						skipOid = tableOid
-						if *singleDataFile && readers[contentToRestore] != nil {
+						if *singleDataFile && readers[contentToRestore] != nil  && readers[contentToRestore].getReaderType() == SUBSET {
 							bytesToDiscard := int64(end[contentToRestore] - start[contentToRestore])
 							_, err = readers[contentToRestore].discardData(bytesToDiscard)
 						}

From edeb4d99e1dd5416a424051919f742851b9fbcce Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Wed, 3 Sep 2025 13:47:15 +0300
Subject: [PATCH 15/46] fmt

---
 helper/restore_helper.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index a2e3edf1d..467cda806 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -379,7 +379,7 @@ func doRestoreAgentInternal(restoreHelper IRestoreHelper) error {
 						logWarn(fmt.Sprintf("Oid %d, Batch %d: Skip file discovered, skipping this relation.", tableOid, batchNum))
 						err = nil
 						skipOid = tableOid
-						if *singleDataFile && readers[contentToRestore] != nil  && readers[contentToRestore].getReaderType() == SUBSET {
+						if *singleDataFile && readers[contentToRestore] != nil && readers[contentToRestore].getReaderType() == SUBSET {
 							bytesToDiscard := int64(end[contentToRestore] - start[contentToRestore])
 							_, err = readers[contentToRestore].discardData(bytesToDiscard)
 						}

From 708cf622e0e3c53116f1a95076a128f1610a81fa Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Wed, 3 Sep 2025 13:49:25 +0300
Subject: [PATCH 16/46] Fix

---
 helper/restore_helper.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index 467cda806..a869a7fd3 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -112,7 +112,7 @@ func (r *RestoreReader) discardData(num int64) (int64, error) {
 
 	n, err := io.CopyN(io.Discard, r.bufReader, num)
 	if err != nil {
-		logVerbose(fmt.Sprintf("%d bytes to discard", n))
+		logVerbose(fmt.Sprintf("%d bytes to discard", num))
 		if err != io.EOF {
 			err = errors.Wrap(discardError, err.Error())
 		}

From 852a4a597e717e9f229dee6473e7b750e3715968 Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Wed, 3 Sep 2025 14:42:04 +0300
Subject: [PATCH 17/46] Fix tests

---
 helper/helper_test.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/helper/helper_test.go b/helper/helper_test.go
index b03069ce2..3613547f4 100644
--- a/helper/helper_test.go
+++ b/helper/helper_test.go
@@ -47,7 +47,7 @@ func (r *restoreReaderTestImpl) closeFileHandle() {
 }
 
 func (r *restoreReaderTestImpl) getReaderType() ReaderType {
-	return "nil"
+	return SUBSET
 }
 
 func (r *restoreReaderTestImpl) discardData(num int64) (int64, error) {

From c95ed61c9d13f51d1577783fe88c776ac511f568 Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Thu, 4 Sep 2025 08:43:36 +0300
Subject: [PATCH 18/46] BeNil -> HaveOccurred

---
 helper/helper_test.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/helper/helper_test.go b/helper/helper_test.go
index 3613547f4..d12302c72 100644
--- a/helper/helper_test.go
+++ b/helper/helper_test.go
@@ -484,7 +484,7 @@ var _ = Describe("helper tests", func() {
 
 			helper := newHelperTest(oidBatch, expectedScenario)
 			err := doRestoreAgentInternal(helper)
-			Expect(err).To(BeNil())
+			Expect(err).ToNot(HaveOccurred())
 			Expect(discarded).To(Equal(int64(18)))
 		})
 		It("calls Wait in waitForPlugin doRestoreAgent for single data file", func() {

From cbaba3841ef8a11f43bb094143a6bc07c9676333 Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Thu, 4 Sep 2025 09:46:40 +0300
Subject: [PATCH 19/46] BeforeEach

---
 helper/helper_test.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/helper/helper_test.go b/helper/helper_test.go
index d12302c72..c894b10c8 100644
--- a/helper/helper_test.go
+++ b/helper/helper_test.go
@@ -547,6 +547,9 @@ var _ = Describe("helper tests", func() {
 		})
 	})
 	Describe("RestoreReader tests", func() {
+		BeforeEach(func() {
+			*onErrorContinue = false
+		})
 		It("waitForPlugin normal completion", func() {
 			test_cmd1 := testPluginCmd{hasProcess_: true}
 			test_reader := new(RestoreReader)

From 4b52d502c3d220f11d18a6c1cbfac8fa25a6ebc9 Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Thu, 4 Sep 2025 10:04:08 +0300
Subject: [PATCH 20/46] writer

---
 helper/helper_test.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/helper/helper_test.go b/helper/helper_test.go
index c894b10c8..81297ddf8 100644
--- a/helper/helper_test.go
+++ b/helper/helper_test.go
@@ -549,6 +549,7 @@ var _ = Describe("helper tests", func() {
 	Describe("RestoreReader tests", func() {
 		BeforeEach(func() {
 			*onErrorContinue = false
+			writer = nil
 		})
 		It("waitForPlugin normal completion", func() {
 			test_cmd1 := testPluginCmd{hasProcess_: true}

From 8caf16a3d9926df70bba014035d22a5bd4cea83c Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Thu, 4 Sep 2025 10:14:28 +0300
Subject: [PATCH 21/46] AfterEach

---
 helper/helper_test.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/helper/helper_test.go b/helper/helper_test.go
index 81297ddf8..0bdbba192 100644
--- a/helper/helper_test.go
+++ b/helper/helper_test.go
@@ -547,7 +547,7 @@ var _ = Describe("helper tests", func() {
 		})
 	})
 	Describe("RestoreReader tests", func() {
-		BeforeEach(func() {
+		AfterEach(func() {
 			*onErrorContinue = false
 			writer = nil
 		})

From d3d034b08dc6887327c78d21ead3a40e54643ba6 Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Fri, 5 Sep 2025 15:04:16 +0300
Subject: [PATCH 22/46] EOF and discardError are not fatal for seekable

---
 helper/restore_helper.go | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index a869a7fd3..e47dd9c96 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -477,7 +477,8 @@ func doRestoreAgentInternal(restoreHelper IRestoreHelper) error {
 
 		if err != nil {
 			logError(fmt.Sprintf("Oid %d, Batch %d: Error encountered: %v", tableOid, batchNum, err))
-			if *onErrorContinue && !errors.Is(err, io.EOF) && !errors.Is(err, discardError) {
+			seekable := readers[contentToRestore] != nil && readers[contentToRestore].getReaderType() == SEEKABLE
+			if *onErrorContinue && (seekable || (!errors.Is(err, io.EOF) && !errors.Is(err, discardError))) {
 				lastError = err
 				err = nil
 				continue

From d18a663dbb350407c06a39deb70fb6b1c85b1aec Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Fri, 5 Sep 2025 15:34:33 +0300
Subject: [PATCH 23/46] Rename

---
 helper/helper_test.go | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/helper/helper_test.go b/helper/helper_test.go
index 0bdbba192..0b182a661 100644
--- a/helper/helper_test.go
+++ b/helper/helper_test.go
@@ -206,43 +206,43 @@ func (pt *testPluginCmd) errLog() {
 }
 
 type limitReader struct {
-	rem int
+	remainder int
 	err error
 }
 
 func (r *limitReader) Read(p []byte) (n int, err error) {
-	if r.rem <= 0 {
+	if r.remainder <= 0 {
 		return 0, r.err
 	}
 
-	if len(p) > r.rem {
-		p = p[0:r.rem]
+	if len(p) > r.remainder {
+		p = p[0:r.remainder]
 	}
 
 	n = len(p)
 	for i := 0; i < n; i++ {
 		p[i] = 1
 	}
-	r.rem -= n
+	r.remainder -= n
 	return
 }
 
 type limitWriter struct {
-	rem int
+	remainder int
 }
 
 func (w *limitWriter) Write(p []byte) (n int, err error) {
-	if w.rem < len(p) {
-		n = w.rem
+	if w.remainder < len(p) {
+		n = w.remainder
 	} else {
 		n = len(p)
 	}
 
-	if w.rem == 0 {
+	if w.remainder == 0 {
 		err = io.ErrShortWrite
 	}
 
-	w.rem -= n
+	w.remainder -= n
 	return
 }
 

From 3cb04faeabf7eeaa5e6671d6282b967f00aa7bf1 Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Sun, 7 Sep 2025 20:06:34 +0300
Subject: [PATCH 24/46] Rewrite test

---
 helper/helper_test.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/helper/helper_test.go b/helper/helper_test.go
index 0b182a661..bdf30d67c 100644
--- a/helper/helper_test.go
+++ b/helper/helper_test.go
@@ -602,7 +602,7 @@ var _ = Describe("helper tests", func() {
 
 			bytesRead, err := test_reader.copyData(18)
 			Expect(bytesRead).To(Equal(int64(18)))
-			Expect(err).To(HaveOccurred())
+			Expect(err).To(Equal(io.ErrShortWrite))
 		})
 		It("CopyData, readerType is SUBSET. EOF", func() {
 			*onErrorContinue = true

From 82c8ef18b22a5039ecdc473feb38a441b1478c11 Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Mon, 8 Sep 2025 10:21:51 +0300
Subject: [PATCH 25/46] Improve logging

---
 helper/restore_helper.go | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index e47dd9c96..1c5984f08 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -112,12 +112,13 @@ func (r *RestoreReader) discardData(num int64) (int64, error) {
 
 	n, err := io.CopyN(io.Discard, r.bufReader, num)
 	if err != nil {
-		logVerbose(fmt.Sprintf("%d bytes to discard", num))
+		logError(fmt.Sprintf("discarded %d bytes from %d. Error: %s", n, num, err.Error()))
 		if err != io.EOF {
 			err = errors.Wrap(discardError, err.Error())
 		}
+	} else {
+		logVerbose(fmt.Sprintf("discarded %d bytes", n))
 	}
-	logVerbose(fmt.Sprintf("discarded %d bytes", n))
 	return n, err
 }
 

From 3b0e82ebe9f7db85ad020b532944f23be5bcece2 Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Mon, 8 Sep 2025 13:48:47 +0300
Subject: [PATCH 26/46] Improve logging

---
 helper/helper_test.go    | 19 ++++++++++++++-----
 helper/restore_helper.go |  6 ++----
 2 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/helper/helper_test.go b/helper/helper_test.go
index bdf30d67c..7fd1f504d 100644
--- a/helper/helper_test.go
+++ b/helper/helper_test.go
@@ -4,6 +4,7 @@ import (
 	"bufio"
 	"fmt"
 	"io"
+	"strings"
 	"os"
 
 	"github.com/greenplum-db/gpbackup/utils"
@@ -628,20 +629,28 @@ var _ = Describe("helper tests", func() {
 
 			bytesRead, err := test_reader.copyData(30)
 			Expect(bytesRead).To(Equal(int64(25)))
-			Expect(err).To(Equal(io.EOF))
+			Expect(errors.Is(err, discardError)).To(Equal(true))
+			Expect(errors.Is(err, io.EOF)).To(Equal(true))
 		})
 		It("CopyData, readerType is SUBSET. Error on write and on read", func() {
 			*onErrorContinue = true
-			writer = bufio.NewWriterSize(&limitWriter{7}, 5)
+			bufSize := 5
+			toCopy := int64(30)
+			rLmt := int64(25)
+			writer = bufio.NewWriterSize(&limitWriter{7}, bufSize)
 
 			test_reader := RestoreReader{
 				readerType: SUBSET,
-				bufReader:  bufio.NewReader(&limitReader{25, io.ErrNoProgress}),
+				bufReader:  bufio.NewReader(&limitReader{int(rLmt), io.ErrNoProgress}),
 			}
 
-			bytesRead, err := test_reader.copyData(30)
-			Expect(bytesRead).To(Equal(int64(25)))
+			bytesRead, err := test_reader.copyData(toCopy)
+			Expect(bytesRead).To(Equal(rLmt))
 			Expect(errors.Is(err, discardError)).To(Equal(true))
+			Expect(errors.Is(err, io.ErrNoProgress)).To(Equal(true))
+			readBeforeErr := int64(bufSize * 2)
+			str := fmt.Sprintf("discarded %d bytes from %d: [", rLmt - readBeforeErr, toCopy - readBeforeErr)
+			Expect(strings.HasPrefix(err.Error(), str)).To(Equal(true))
 		})
 	})
 })
diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index 1c5984f08..123453f5f 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -112,10 +112,8 @@ func (r *RestoreReader) discardData(num int64) (int64, error) {
 
 	n, err := io.CopyN(io.Discard, r.bufReader, num)
 	if err != nil {
-		logError(fmt.Sprintf("discarded %d bytes from %d. Error: %s", n, num, err.Error()))
-		if err != io.EOF {
-			err = errors.Wrap(discardError, err.Error())
-		}
+		err = fmt.Errorf("discarded %d bytes from %d: [%w: [%w]]", n, num, err, discardError)
+		logError(err.Error())
 	} else {
 		logVerbose(fmt.Sprintf("discarded %d bytes", n))
 	}

From 28807a105a2edf90e61f91df15c528e32e9ab53a Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Mon, 8 Sep 2025 15:09:53 +0300
Subject: [PATCH 27/46] Simplify

---
 helper/restore_helper.go | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index 123453f5f..575927c7c 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -476,14 +476,17 @@ func doRestoreAgentInternal(restoreHelper IRestoreHelper) error {
 
 		if err != nil {
 			logError(fmt.Sprintf("Oid %d, Batch %d: Error encountered: %v", tableOid, batchNum, err))
+			if (!*onErrorContinue) {
+				return err
+			}
+
 			seekable := readers[contentToRestore] != nil && readers[contentToRestore].getReaderType() == SEEKABLE
-			if *onErrorContinue && (seekable || (!errors.Is(err, io.EOF) && !errors.Is(err, discardError))) {
-				lastError = err
-				err = nil
-				continue
-			} else {
+			if !seekable && (errors.Is(err, io.EOF) || errors.Is(err, discardError)) {
 				return err
 			}
+
+			lastError = err
+			err = nil
 		}
 	}
 

From 327db888dfbbab69ef4b5368c588a924db1021f6 Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Mon, 8 Sep 2025 15:23:42 +0300
Subject: [PATCH 28/46] Add comment

---
 helper/restore_helper.go | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index 575927c7c..4cf1c4afd 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -480,6 +480,8 @@ func doRestoreAgentInternal(restoreHelper IRestoreHelper) error {
 				return err
 			}
 
+			// When we read data from NONSEEKABLE or SUBSET, we cannot read more when EOF or discardError happens.
+			// These errors are not a problem for SEEKABLE, because the next table may be in the middle of the file. 
 			seekable := readers[contentToRestore] != nil && readers[contentToRestore].getReaderType() == SEEKABLE
 			if !seekable && (errors.Is(err, io.EOF) || errors.Is(err, discardError)) {
 				return err

From f3b8da089beec9aaeea47ed424c964e874a688e9 Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Mon, 8 Sep 2025 15:34:38 +0300
Subject: [PATCH 29/46] split conditions

---
 helper/restore_helper.go | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index 4cf1c4afd..c0b448cb0 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -482,9 +482,10 @@ func doRestoreAgentInternal(restoreHelper IRestoreHelper) error {
 
 			// When we read data from NONSEEKABLE or SUBSET, we cannot read more when EOF or discardError happens.
 			// These errors are not a problem for SEEKABLE, because the next table may be in the middle of the file. 
-			seekable := readers[contentToRestore] != nil && readers[contentToRestore].getReaderType() == SEEKABLE
-			if !seekable && (errors.Is(err, io.EOF) || errors.Is(err, discardError)) {
-				return err
+			if readers[contentToRestore] == nil || readers[contentToRestore].getReaderType() != SEEKABLE {
+				if errors.Is(err, io.EOF) || errors.Is(err, discardError) {
+					return err
+				}
 			}
 
 			lastError = err

From 3cad64a68dcea288a24414fc53e2322c956c813c Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Mon, 8 Sep 2025 16:50:07 +0300
Subject: [PATCH 30/46] Remove parenthesis

---
 helper/restore_helper.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index c0b448cb0..58866947d 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -476,7 +476,7 @@ func doRestoreAgentInternal(restoreHelper IRestoreHelper) error {
 
 		if err != nil {
 			logError(fmt.Sprintf("Oid %d, Batch %d: Error encountered: %v", tableOid, batchNum, err))
-			if (!*onErrorContinue) {
+			if !*onErrorContinue {
 				return err
 			}
 

From b87a05ddd8304dbdba9215af33fee1f0f7229d7a Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Tue, 9 Sep 2025 15:08:02 +0300
Subject: [PATCH 31/46] Revert changes about exit from doRestoreAgentInternal

---
 helper/restore_helper.go | 17 +++++------------
 1 file changed, 5 insertions(+), 12 deletions(-)

diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index 58866947d..71c2772bb 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -476,20 +476,13 @@ func doRestoreAgentInternal(restoreHelper IRestoreHelper) error {
 
 		if err != nil {
 			logError(fmt.Sprintf("Oid %d, Batch %d: Error encountered: %v", tableOid, batchNum, err))
-			if !*onErrorContinue {
+			if *onErrorContinue {
+				lastError = err
+				err = nil
+				continue
+			} else {
 				return err
 			}
-
-			// When we read data from NONSEEKABLE or SUBSET, we cannot read more when EOF or discardError happens.
-			// These errors are not a problem for SEEKABLE, because the next table may be in the middle of the file. 
-			if readers[contentToRestore] == nil || readers[contentToRestore].getReaderType() != SEEKABLE {
-				if errors.Is(err, io.EOF) || errors.Is(err, discardError) {
-					return err
-				}
-			}
-
-			lastError = err
-			err = nil
 		}
 	}
 

From cb926b2bdf816cdf542f112892c05abb8f2a046c Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Thu, 11 Sep 2025 10:20:15 +0300
Subject: [PATCH 32/46] Add exit on discardError

---
 helper/restore_helper.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index 71c2772bb..9b3a861ad 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -476,7 +476,7 @@ func doRestoreAgentInternal(restoreHelper IRestoreHelper) error {
 
 		if err != nil {
 			logError(fmt.Sprintf("Oid %d, Batch %d: Error encountered: %v", tableOid, batchNum, err))
-			if *onErrorContinue {
+			if *onErrorContinue && !errors.Is(err, discardError) {
 				lastError = err
 				err = nil
 				continue

From 12094de252e0575560488f6fc4276e76fd4f4c6f Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Thu, 11 Sep 2025 13:13:03 +0300
Subject: [PATCH 33/46] Don't miss CopyN error

---
 helper/helper_test.go    | 35 ++++++++++++++++++++++++++---------
 helper/restore_helper.go |  3 ++-
 2 files changed, 28 insertions(+), 10 deletions(-)

diff --git a/helper/helper_test.go b/helper/helper_test.go
index 7fd1f504d..75b4ad54e 100644
--- a/helper/helper_test.go
+++ b/helper/helper_test.go
@@ -594,16 +594,21 @@ var _ = Describe("helper tests", func() {
 		})
 		It("CopyData, readerType is SUBSET. Error on write", func() {
 			*onErrorContinue = true
-			writer = bufio.NewWriterSize(&limitWriter{7}, 5)
+			bufSize := 5
+			toRead := int64(18)
+			writer = bufio.NewWriterSize(&limitWriter{7}, bufSize)
 
 			test_reader := RestoreReader{
 				readerType: SUBSET,
 				bufReader:  bufio.NewReader(&limitReader{100, io.EOF}),
 			}
 
-			bytesRead, err := test_reader.copyData(18)
-			Expect(bytesRead).To(Equal(int64(18)))
-			Expect(err).To(Equal(io.ErrShortWrite))
+			bytesRead, err := test_reader.copyData(toRead)
+			Expect(bytesRead).To(Equal(toRead))
+			Expect(errors.Is(err, io.ErrShortWrite)).To(Equal(true))
+			str := fmt.Sprintf("copied %d bytes from %d: [", bufSize * 2, toRead)
+			Expect(strings.HasPrefix(err.Error(), str)).To(Equal(true))
+
 		})
 		It("CopyData, readerType is SUBSET. EOF", func() {
 			*onErrorContinue = true
@@ -620,17 +625,26 @@ var _ = Describe("helper tests", func() {
 		})
 		It("CopyData, readerType is SUBSET. Error on write and EOF", func() {
 			*onErrorContinue = true
-			writer = bufio.NewWriterSize(&limitWriter{7}, 5)
+			bufSize := 5
+			toCopy := int64(30)
+			rLmt := int64(25)
+			writer = bufio.NewWriterSize(&limitWriter{7}, bufSize)
 
 			test_reader := RestoreReader{
 				readerType: SUBSET,
-				bufReader:  bufio.NewReader(&limitReader{25, io.EOF}),
+				bufReader:  bufio.NewReader(&limitReader{int(rLmt), io.EOF}),
 			}
 
-			bytesRead, err := test_reader.copyData(30)
-			Expect(bytesRead).To(Equal(int64(25)))
+			bytesRead, err := test_reader.copyData(toCopy)
+			Expect(bytesRead).To(Equal(rLmt))
 			Expect(errors.Is(err, discardError)).To(Equal(true))
+			Expect(errors.Is(err, io.ErrShortWrite)).To(Equal(true))
 			Expect(errors.Is(err, io.EOF)).To(Equal(true))
+			readBeforeErr := int64(bufSize * 2)
+			prefix := fmt.Sprintf("discard error in copyData: [discarded %d bytes from %d: [", rLmt - readBeforeErr, toCopy - readBeforeErr)
+			Expect(strings.HasPrefix(err.Error(), prefix)).To(Equal(true))
+			strCopied := fmt.Sprintf("[copied %d bytes from %d: [", readBeforeErr, toCopy)
+			Expect(strings.Contains(err.Error(), strCopied)).To(Equal(true))
 		})
 		It("CopyData, readerType is SUBSET. Error on write and on read", func() {
 			*onErrorContinue = true
@@ -647,10 +661,13 @@ var _ = Describe("helper tests", func() {
 			bytesRead, err := test_reader.copyData(toCopy)
 			Expect(bytesRead).To(Equal(rLmt))
 			Expect(errors.Is(err, discardError)).To(Equal(true))
+			Expect(errors.Is(err, io.ErrShortWrite)).To(Equal(true))
 			Expect(errors.Is(err, io.ErrNoProgress)).To(Equal(true))
 			readBeforeErr := int64(bufSize * 2)
-			str := fmt.Sprintf("discarded %d bytes from %d: [", rLmt - readBeforeErr, toCopy - readBeforeErr)
+			str := fmt.Sprintf("discard error in copyData: [discarded %d bytes from %d: [", rLmt - readBeforeErr, toCopy - readBeforeErr)
 			Expect(strings.HasPrefix(err.Error(), str)).To(Equal(true))
+			strCopied := fmt.Sprintf("[copied %d bytes from %d: [", readBeforeErr, toCopy)
+			Expect(strings.Contains(err.Error(), strCopied)).To(Equal(true))
 		})
 	})
 })
diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index 9b3a861ad..9e9c273c9 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -131,10 +131,11 @@ func (r *RestoreReader) copyData(num int64) (int64, error) {
 	case SUBSET:
 		bytesRead, err = io.CopyN(writer, r.bufReader, num)
 		if err != nil && err != io.EOF && *onErrorContinue {
+			err = fmt.Errorf("copied %d bytes from %d: [%w]", bytesRead, num, err)
 			bytesDiscard, errDiscard := r.discardData(num - bytesRead)
 			bytesRead += bytesDiscard
 			if errDiscard != nil {
-				err = errDiscard
+				err = fmt.Errorf("discard error in copyData: [%w: [%w]]", errDiscard, err)
 			}
 		}
 	}

From 52568ff8c066e163aaf5d9e3752bb216f92d314e Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Thu, 11 Sep 2025 13:15:28 +0300
Subject: [PATCH 34/46] change variable name

---
 helper/helper_test.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/helper/helper_test.go b/helper/helper_test.go
index 75b4ad54e..dba72625c 100644
--- a/helper/helper_test.go
+++ b/helper/helper_test.go
@@ -664,8 +664,8 @@ var _ = Describe("helper tests", func() {
 			Expect(errors.Is(err, io.ErrShortWrite)).To(Equal(true))
 			Expect(errors.Is(err, io.ErrNoProgress)).To(Equal(true))
 			readBeforeErr := int64(bufSize * 2)
-			str := fmt.Sprintf("discard error in copyData: [discarded %d bytes from %d: [", rLmt - readBeforeErr, toCopy - readBeforeErr)
-			Expect(strings.HasPrefix(err.Error(), str)).To(Equal(true))
+			prefix := fmt.Sprintf("discard error in copyData: [discarded %d bytes from %d: [", rLmt - readBeforeErr, toCopy - readBeforeErr)
+			Expect(strings.HasPrefix(err.Error(), prefix)).To(Equal(true))
 			strCopied := fmt.Sprintf("[copied %d bytes from %d: [", readBeforeErr, toCopy)
 			Expect(strings.Contains(err.Error(), strCopied)).To(Equal(true))
 		})

From 8bb569ffb62e9bbf6bfabb945bcb546bde21fc62 Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Fri, 12 Sep 2025 13:44:32 +0300
Subject: [PATCH 35/46] Fix hanging

---
 helper/helper_test.go    |  2 --
 helper/restore_helper.go | 30 ++++++++++++++++++++++--------
 2 files changed, 22 insertions(+), 10 deletions(-)

diff --git a/helper/helper_test.go b/helper/helper_test.go
index dba72625c..ab59b35a5 100644
--- a/helper/helper_test.go
+++ b/helper/helper_test.go
@@ -637,7 +637,6 @@ var _ = Describe("helper tests", func() {
 
 			bytesRead, err := test_reader.copyData(toCopy)
 			Expect(bytesRead).To(Equal(rLmt))
-			Expect(errors.Is(err, discardError)).To(Equal(true))
 			Expect(errors.Is(err, io.ErrShortWrite)).To(Equal(true))
 			Expect(errors.Is(err, io.EOF)).To(Equal(true))
 			readBeforeErr := int64(bufSize * 2)
@@ -660,7 +659,6 @@ var _ = Describe("helper tests", func() {
 
 			bytesRead, err := test_reader.copyData(toCopy)
 			Expect(bytesRead).To(Equal(rLmt))
-			Expect(errors.Is(err, discardError)).To(Equal(true))
 			Expect(errors.Is(err, io.ErrShortWrite)).To(Equal(true))
 			Expect(errors.Is(err, io.ErrNoProgress)).To(Equal(true))
 			readBeforeErr := int64(bufSize * 2)
diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index 9e9c273c9..81611e4df 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -40,8 +40,6 @@ var (
 	contentRE   *regexp.Regexp
 )
 
-var discardError = errors.New("helper: discard error")
-
 /* IRestoreReader interface to wrap the underlying reader.
  * getReaderType() identifies how the reader can be used
  * SEEKABLE uses seekReader. Used when restoring from uncompressed data with filters from local filesystem
@@ -65,6 +63,7 @@ type RestoreReader struct {
 	seekReader io.ReadSeeker
 	pluginCmd  IPluginCmd
 	readerType ReaderType
+	discardErr error
 }
 
 // Wait for plugin process that should be already finished. This should be
@@ -110,14 +109,19 @@ func (r *RestoreReader) discardData(num int64) (int64, error) {
 		panic("discardData should be called for readerType == SUBSET only")
 	}
 
+	if r.discardErr != nil {
+		logVerbose(fmt.Sprintf("%d bytes to discard, but discard error has already been set. Don't read", num))
+		return 0, r.discardErr
+	}
+
 	n, err := io.CopyN(io.Discard, r.bufReader, num)
-	if err != nil {
-		err = fmt.Errorf("discarded %d bytes from %d: [%w: [%w]]", n, num, err, discardError)
-		logError(err.Error())
-	} else {
+	if err == nil {
 		logVerbose(fmt.Sprintf("discarded %d bytes", n))
+	} else {
+		r.discardErr = fmt.Errorf("discarded %d bytes from %d: [%w]", n, num, err)
+		logError(r.discardErr.Error())
 	}
-	return n, err
+	return n, r.discardErr
 }
 
 func (r *RestoreReader) copyData(num int64) (int64, error) {
@@ -129,6 +133,11 @@ func (r *RestoreReader) copyData(num int64) (int64, error) {
 	case NONSEEKABLE:
 		bytesRead, err = io.CopyN(writer, r.bufReader, num)
 	case SUBSET:
+		if r.discardErr != nil {
+			logVerbose(fmt.Sprintf("%d bytes to copy, but discard error has already been set. Don't read", num))
+			return 0, r.discardErr
+		}
+
 		bytesRead, err = io.CopyN(writer, r.bufReader, num)
 		if err != nil && err != io.EOF && *onErrorContinue {
 			err = fmt.Errorf("copied %d bytes from %d: [%w]", bytesRead, num, err)
@@ -149,6 +158,11 @@ func (r *RestoreReader) copyAllData() (int64, error) {
 	case SEEKABLE:
 		bytesRead, err = io.Copy(writer, r.seekReader)
 	case NONSEEKABLE, SUBSET:
+		if r.discardErr != nil {
+			logVerbose("copyAllData: discard error has already been set. Don't read")
+			return 0, r.discardErr
+		}
+
 		bytesRead, err = io.Copy(writer, r.bufReader)
 	}
 	return bytesRead, err
@@ -477,7 +491,7 @@ func doRestoreAgentInternal(restoreHelper IRestoreHelper) error {
 
 		if err != nil {
 			logError(fmt.Sprintf("Oid %d, Batch %d: Error encountered: %v", tableOid, batchNum, err))
-			if *onErrorContinue && !errors.Is(err, discardError) {
+			if *onErrorContinue {
 				lastError = err
 				err = nil
 				continue

From aa88bf067505352b580075cd6785c98133d331ad Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Mon, 15 Sep 2025 08:42:16 +0300
Subject: [PATCH 36/46] Fix logging

---
 helper/restore_helper.go | 29 ++++++++++++++++-------------
 1 file changed, 16 insertions(+), 13 deletions(-)

diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index 81611e4df..318404251 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -40,6 +40,8 @@ var (
 	contentRE   *regexp.Regexp
 )
 
+var discardError = errors.New("discard error occurred when restoring a previous table")
+
 /* IRestoreReader interface to wrap the underlying reader.
  * getReaderType() identifies how the reader can be used
  * SEEKABLE uses seekReader. Used when restoring from uncompressed data with filters from local filesystem
@@ -63,7 +65,7 @@ type RestoreReader struct {
 	seekReader io.ReadSeeker
 	pluginCmd  IPluginCmd
 	readerType ReaderType
-	discardErr error
+	discardErr bool
 }
 
 // Wait for plugin process that should be already finished. This should be
@@ -109,19 +111,20 @@ func (r *RestoreReader) discardData(num int64) (int64, error) {
 		panic("discardData should be called for readerType == SUBSET only")
 	}
 
-	if r.discardErr != nil {
-		logVerbose(fmt.Sprintf("%d bytes to discard, but discard error has already been set. Don't read", num))
-		return 0, r.discardErr
+	if r.discardErr {
+		logVerbose(fmt.Sprintf("%d bytes to discard, but discard error has already occurred. Don't read", num))
+		return 0, discardError
 	}
 
 	n, err := io.CopyN(io.Discard, r.bufReader, num)
 	if err == nil {
 		logVerbose(fmt.Sprintf("discarded %d bytes", n))
 	} else {
-		r.discardErr = fmt.Errorf("discarded %d bytes from %d: [%w]", n, num, err)
-		logError(r.discardErr.Error())
+		r.discardErr = true
+		err = fmt.Errorf("discarded %d bytes from %d: [%w]", n, num, err)
+		logError(err.Error())
 	}
-	return n, r.discardErr
+	return n, err
 }
 
 func (r *RestoreReader) copyData(num int64) (int64, error) {
@@ -133,9 +136,9 @@ func (r *RestoreReader) copyData(num int64) (int64, error) {
 	case NONSEEKABLE:
 		bytesRead, err = io.CopyN(writer, r.bufReader, num)
 	case SUBSET:
-		if r.discardErr != nil {
-			logVerbose(fmt.Sprintf("%d bytes to copy, but discard error has already been set. Don't read", num))
-			return 0, r.discardErr
+		if r.discardErr {
+			logVerbose(fmt.Sprintf("%d bytes to copy, but discard error has already occurred. Don't read", num))
+			return 0, discardError
 		}
 
 		bytesRead, err = io.CopyN(writer, r.bufReader, num)
@@ -158,9 +161,9 @@ func (r *RestoreReader) copyAllData() (int64, error) {
 	case SEEKABLE:
 		bytesRead, err = io.Copy(writer, r.seekReader)
 	case NONSEEKABLE, SUBSET:
-		if r.discardErr != nil {
-			logVerbose("copyAllData: discard error has already been set. Don't read")
-			return 0, r.discardErr
+		if r.discardErr {
+			logVerbose("copyAllData: discard error has already occurred. Don't read")
+			return 0, discardError
 		}
 
 		bytesRead, err = io.Copy(writer, r.bufReader)

From d6663ec239e94ea9650ec236944b4fe41fb945bf Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Mon, 15 Sep 2025 10:23:07 +0300
Subject: [PATCH 37/46] Revert changes in CopyAllData

---
 helper/restore_helper.go | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index 318404251..1df69537b 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -161,11 +161,6 @@ func (r *RestoreReader) copyAllData() (int64, error) {
 	case SEEKABLE:
 		bytesRead, err = io.Copy(writer, r.seekReader)
 	case NONSEEKABLE, SUBSET:
-		if r.discardErr {
-			logVerbose("copyAllData: discard error has already occurred. Don't read")
-			return 0, discardError
-		}
-
 		bytesRead, err = io.Copy(writer, r.bufReader)
 	}
 	return bytesRead, err

From c644bea2485fc55acc92b24693a1af1d05fdfc4b Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Mon, 15 Sep 2025 11:04:51 +0300
Subject: [PATCH 38/46] Rewrite to use Join, go fmt

---
 helper/helper_test.go    | 18 +++++++++---------
 helper/restore_helper.go |  4 +++-
 2 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/helper/helper_test.go b/helper/helper_test.go
index ab59b35a5..189ebe6f2 100644
--- a/helper/helper_test.go
+++ b/helper/helper_test.go
@@ -4,8 +4,8 @@ import (
 	"bufio"
 	"fmt"
 	"io"
-	"strings"
 	"os"
+	"strings"
 
 	"github.com/greenplum-db/gpbackup/utils"
 	"golang.org/x/sys/unix"
@@ -20,7 +20,7 @@ import (
 var (
 	testDir     = "/tmp/helper_test/20180101/20180101010101"
 	testTocFile = fmt.Sprintf("%s/test_toc.yaml", testDir)
-	discarded int64
+	discarded   int64
 )
 
 type restoreReaderTestImpl struct {
@@ -208,7 +208,7 @@ func (pt *testPluginCmd) errLog() {
 
 type limitReader struct {
 	remainder int
-	err error
+	err       error
 }
 
 func (r *limitReader) Read(p []byte) (n int, err error) {
@@ -476,7 +476,7 @@ var _ = Describe("helper tests", func() {
 			}()
 
 			oidBatch := []oidWithBatch{
-				{1 /* The first oid from TOC */, 0}, 
+				{1 /* The first oid from TOC */, 0},
 			}
 
 			expectedScenario := []helperTestStep{
@@ -606,7 +606,7 @@ var _ = Describe("helper tests", func() {
 			bytesRead, err := test_reader.copyData(toRead)
 			Expect(bytesRead).To(Equal(toRead))
 			Expect(errors.Is(err, io.ErrShortWrite)).To(Equal(true))
-			str := fmt.Sprintf("copied %d bytes from %d: [", bufSize * 2, toRead)
+			str := fmt.Sprintf("copied %d bytes from %d: [", bufSize*2, toRead)
 			Expect(strings.HasPrefix(err.Error(), str)).To(Equal(true))
 
 		})
@@ -640,9 +640,9 @@ var _ = Describe("helper tests", func() {
 			Expect(errors.Is(err, io.ErrShortWrite)).To(Equal(true))
 			Expect(errors.Is(err, io.EOF)).To(Equal(true))
 			readBeforeErr := int64(bufSize * 2)
-			prefix := fmt.Sprintf("discard error in copyData: [discarded %d bytes from %d: [", rLmt - readBeforeErr, toCopy - readBeforeErr)
+			prefix := fmt.Sprintf("discard error in copyData: [discarded %d bytes from %d: [", rLmt-readBeforeErr, toCopy-readBeforeErr)
 			Expect(strings.HasPrefix(err.Error(), prefix)).To(Equal(true))
-			strCopied := fmt.Sprintf("[copied %d bytes from %d: [", readBeforeErr, toCopy)
+			strCopied := fmt.Sprintf("copied %d bytes from %d: [", readBeforeErr, toCopy)
 			Expect(strings.Contains(err.Error(), strCopied)).To(Equal(true))
 		})
 		It("CopyData, readerType is SUBSET. Error on write and on read", func() {
@@ -662,9 +662,9 @@ var _ = Describe("helper tests", func() {
 			Expect(errors.Is(err, io.ErrShortWrite)).To(Equal(true))
 			Expect(errors.Is(err, io.ErrNoProgress)).To(Equal(true))
 			readBeforeErr := int64(bufSize * 2)
-			prefix := fmt.Sprintf("discard error in copyData: [discarded %d bytes from %d: [", rLmt - readBeforeErr, toCopy - readBeforeErr)
+			prefix := fmt.Sprintf("discard error in copyData: [discarded %d bytes from %d: [", rLmt-readBeforeErr, toCopy-readBeforeErr)
 			Expect(strings.HasPrefix(err.Error(), prefix)).To(Equal(true))
-			strCopied := fmt.Sprintf("[copied %d bytes from %d: [", readBeforeErr, toCopy)
+			strCopied := fmt.Sprintf("copied %d bytes from %d: [", readBeforeErr, toCopy)
 			Expect(strings.Contains(err.Error(), strCopied)).To(Equal(true))
 		})
 	})
diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index 1df69537b..d2513857e 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -4,6 +4,7 @@ import (
 	"bufio"
 	"bytes"
 	"compress/gzip"
+	errorsStd "errors"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -147,7 +148,8 @@ func (r *RestoreReader) copyData(num int64) (int64, error) {
 			bytesDiscard, errDiscard := r.discardData(num - bytesRead)
 			bytesRead += bytesDiscard
 			if errDiscard != nil {
-				err = fmt.Errorf("discard error in copyData: [%w: [%w]]", errDiscard, err)
+				err = errorsStd.Join(errDiscard, err)
+				err = fmt.Errorf("discard error in copyData: [%w]", err)
 			}
 		}
 	}

From 5420290b94933f0a7a54be8b50b6c802c6673fae Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Mon, 15 Sep 2025 16:25:52 +0300
Subject: [PATCH 39/46] Add RestoreReader tests

---
 helper/helper_test.go | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/helper/helper_test.go b/helper/helper_test.go
index 189ebe6f2..4f97cfdcc 100644
--- a/helper/helper_test.go
+++ b/helper/helper_test.go
@@ -644,6 +644,10 @@ var _ = Describe("helper tests", func() {
 			Expect(strings.HasPrefix(err.Error(), prefix)).To(Equal(true))
 			strCopied := fmt.Sprintf("copied %d bytes from %d: [", readBeforeErr, toCopy)
 			Expect(strings.Contains(err.Error(), strCopied)).To(Equal(true))
+
+			bytesRead, err = test_reader.copyData(10)
+			Expect(bytesRead).To(Equal(int64(0)))
+			Expect(err).To(Equal(discardError))
 		})
 		It("CopyData, readerType is SUBSET. Error on write and on read", func() {
 			*onErrorContinue = true
@@ -666,6 +670,10 @@ var _ = Describe("helper tests", func() {
 			Expect(strings.HasPrefix(err.Error(), prefix)).To(Equal(true))
 			strCopied := fmt.Sprintf("copied %d bytes from %d: [", readBeforeErr, toCopy)
 			Expect(strings.Contains(err.Error(), strCopied)).To(Equal(true))
+
+			bytesRead, err = test_reader.copyData(10)
+			Expect(bytesRead).To(Equal(int64(0)))
+			Expect(err).To(Equal(discardError))
 		})
 	})
 })

From c7c9d66eb6811cb6fda77f222b8d45d427b4a412 Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Tue, 16 Sep 2025 09:52:24 +0300
Subject: [PATCH 40/46] Remove discardError

---
 helper/helper_test.go    | 12 ++++++++++--
 helper/restore_helper.go | 12 ++++++------
 2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/helper/helper_test.go b/helper/helper_test.go
index 4f97cfdcc..f7854789b 100644
--- a/helper/helper_test.go
+++ b/helper/helper_test.go
@@ -647,7 +647,11 @@ var _ = Describe("helper tests", func() {
 
 			bytesRead, err = test_reader.copyData(10)
 			Expect(bytesRead).To(Equal(int64(0)))
-			Expect(err).To(Equal(discardError))
+			Expect(err.Error()).To(Equal("10 bytes to copy, but discard error has already occurred. Don't read"))
+
+			bytesRead, err = test_reader.discardData(5)
+			Expect(bytesRead).To(Equal(int64(0)))
+			Expect(err.Error()).To(Equal("5 bytes to discard, but discard error has already occurred. Don't read"))
 		})
 		It("CopyData, readerType is SUBSET. Error on write and on read", func() {
 			*onErrorContinue = true
@@ -673,7 +677,11 @@ var _ = Describe("helper tests", func() {
 
 			bytesRead, err = test_reader.copyData(10)
 			Expect(bytesRead).To(Equal(int64(0)))
-			Expect(err).To(Equal(discardError))
+			Expect(err.Error()).To(Equal("10 bytes to copy, but discard error has already occurred. Don't read"))
+
+			bytesRead, err = test_reader.discardData(5)
+			Expect(bytesRead).To(Equal(int64(0)))
+			Expect(err.Error()).To(Equal("5 bytes to discard, but discard error has already occurred. Don't read"))
 		})
 	})
 })
diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index d2513857e..cefa30efa 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -41,8 +41,6 @@ var (
 	contentRE   *regexp.Regexp
 )
 
-var discardError = errors.New("discard error occurred when restoring a previous table")
-
 /* IRestoreReader interface to wrap the underlying reader.
  * getReaderType() identifies how the reader can be used
  * SEEKABLE uses seekReader. Used when restoring from uncompressed data with filters from local filesystem
@@ -113,8 +111,9 @@ func (r *RestoreReader) discardData(num int64) (int64, error) {
 	}
 
 	if r.discardErr {
-		logVerbose(fmt.Sprintf("%d bytes to discard, but discard error has already occurred. Don't read", num))
-		return 0, discardError
+		err := fmt.Errorf("%d bytes to discard, but discard error has already occurred. Don't read", num)
+		logVerbose(err.Error())
+		return 0, err
 	}
 
 	n, err := io.CopyN(io.Discard, r.bufReader, num)
@@ -138,8 +137,9 @@ func (r *RestoreReader) copyData(num int64) (int64, error) {
 		bytesRead, err = io.CopyN(writer, r.bufReader, num)
 	case SUBSET:
 		if r.discardErr {
-			logVerbose(fmt.Sprintf("%d bytes to copy, but discard error has already occurred. Don't read", num))
-			return 0, discardError
+			err := fmt.Errorf("%d bytes to copy, but discard error has already occurred. Don't read", num)
+			logVerbose(err.Error())
+			return 0, err
 		}
 
 		bytesRead, err = io.CopyN(writer, r.bufReader, num)

From 769bddc2809cdaa7868981bac73d93790ec00c35 Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Tue, 16 Sep 2025 10:37:34 +0300
Subject: [PATCH 41/46] Replace fmt.Errorf with errors.Wrap

---
 helper/helper_test.go    | 10 +++++-----
 helper/restore_helper.go |  6 +++---
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/helper/helper_test.go b/helper/helper_test.go
index f7854789b..bd5551c13 100644
--- a/helper/helper_test.go
+++ b/helper/helper_test.go
@@ -606,7 +606,7 @@ var _ = Describe("helper tests", func() {
 			bytesRead, err := test_reader.copyData(toRead)
 			Expect(bytesRead).To(Equal(toRead))
 			Expect(errors.Is(err, io.ErrShortWrite)).To(Equal(true))
-			str := fmt.Sprintf("copied %d bytes from %d: [", bufSize*2, toRead)
+			str := fmt.Sprintf("copied %d bytes from %d: ", bufSize*2, toRead)
 			Expect(strings.HasPrefix(err.Error(), str)).To(Equal(true))
 
 		})
@@ -640,9 +640,9 @@ var _ = Describe("helper tests", func() {
 			Expect(errors.Is(err, io.ErrShortWrite)).To(Equal(true))
 			Expect(errors.Is(err, io.EOF)).To(Equal(true))
 			readBeforeErr := int64(bufSize * 2)
-			prefix := fmt.Sprintf("discard error in copyData: [discarded %d bytes from %d: [", rLmt-readBeforeErr, toCopy-readBeforeErr)
+			prefix := fmt.Sprintf("discard error in copyData: discarded %d bytes from %d: ", rLmt-readBeforeErr, toCopy-readBeforeErr)
 			Expect(strings.HasPrefix(err.Error(), prefix)).To(Equal(true))
-			strCopied := fmt.Sprintf("copied %d bytes from %d: [", readBeforeErr, toCopy)
+			strCopied := fmt.Sprintf("copied %d bytes from %d: ", readBeforeErr, toCopy)
 			Expect(strings.Contains(err.Error(), strCopied)).To(Equal(true))
 
 			bytesRead, err = test_reader.copyData(10)
@@ -670,9 +670,9 @@ var _ = Describe("helper tests", func() {
 			Expect(errors.Is(err, io.ErrShortWrite)).To(Equal(true))
 			Expect(errors.Is(err, io.ErrNoProgress)).To(Equal(true))
 			readBeforeErr := int64(bufSize * 2)
-			prefix := fmt.Sprintf("discard error in copyData: [discarded %d bytes from %d: [", rLmt-readBeforeErr, toCopy-readBeforeErr)
+			prefix := fmt.Sprintf("discard error in copyData: discarded %d bytes from %d: ", rLmt-readBeforeErr, toCopy-readBeforeErr)
 			Expect(strings.HasPrefix(err.Error(), prefix)).To(Equal(true))
-			strCopied := fmt.Sprintf("copied %d bytes from %d: [", readBeforeErr, toCopy)
+			strCopied := fmt.Sprintf("copied %d bytes from %d: ", readBeforeErr, toCopy)
 			Expect(strings.Contains(err.Error(), strCopied)).To(Equal(true))
 
 			bytesRead, err = test_reader.copyData(10)
diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index cefa30efa..7196e8ead 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -121,7 +121,7 @@ func (r *RestoreReader) discardData(num int64) (int64, error) {
 		logVerbose(fmt.Sprintf("discarded %d bytes", n))
 	} else {
 		r.discardErr = true
-		err = fmt.Errorf("discarded %d bytes from %d: [%w]", n, num, err)
+		err = errors.Wrapf(err, "discarded %d bytes from %d", n, num)
 		logError(err.Error())
 	}
 	return n, err
@@ -144,12 +144,12 @@ func (r *RestoreReader) copyData(num int64) (int64, error) {
 
 		bytesRead, err = io.CopyN(writer, r.bufReader, num)
 		if err != nil && err != io.EOF && *onErrorContinue {
-			err = fmt.Errorf("copied %d bytes from %d: [%w]", bytesRead, num, err)
+			err = errors.Wrapf(err, "copied %d bytes from %d", bytesRead, num)
 			bytesDiscard, errDiscard := r.discardData(num - bytesRead)
 			bytesRead += bytesDiscard
 			if errDiscard != nil {
 				err = errorsStd.Join(errDiscard, err)
-				err = fmt.Errorf("discard error in copyData: [%w]", err)
+				err = errors.Wrap(err, "discard error in copyData")
 			}
 		}
 	}

From bba8d88c9385f8cbf6546d276f8538bfd50df922 Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Tue, 16 Sep 2025 11:47:24 +0300
Subject: [PATCH 42/46] Fix error message

---
 helper/helper_test.go    | 8 ++++----
 helper/restore_helper.go | 4 ++--
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/helper/helper_test.go b/helper/helper_test.go
index bd5551c13..b68e71a7d 100644
--- a/helper/helper_test.go
+++ b/helper/helper_test.go
@@ -647,11 +647,11 @@ var _ = Describe("helper tests", func() {
 
 			bytesRead, err = test_reader.copyData(10)
 			Expect(bytesRead).To(Equal(int64(0)))
-			Expect(err.Error()).To(Equal("10 bytes to copy, but discard error has already occurred. Don't read"))
+			Expect(err.Error()).To(Equal("10 bytes to copy, but discard error has already occurred. Skipping read."))
 
 			bytesRead, err = test_reader.discardData(5)
 			Expect(bytesRead).To(Equal(int64(0)))
-			Expect(err.Error()).To(Equal("5 bytes to discard, but discard error has already occurred. Don't read"))
+			Expect(err.Error()).To(Equal("5 bytes to discard, but discard error has already occurred. Skipping read."))
 		})
 		It("CopyData, readerType is SUBSET. Error on write and on read", func() {
 			*onErrorContinue = true
@@ -677,11 +677,11 @@ var _ = Describe("helper tests", func() {
 
 			bytesRead, err = test_reader.copyData(10)
 			Expect(bytesRead).To(Equal(int64(0)))
-			Expect(err.Error()).To(Equal("10 bytes to copy, but discard error has already occurred. Don't read"))
+			Expect(err.Error()).To(Equal("10 bytes to copy, but discard error has already occurred. Skipping read."))
 
 			bytesRead, err = test_reader.discardData(5)
 			Expect(bytesRead).To(Equal(int64(0)))
-			Expect(err.Error()).To(Equal("5 bytes to discard, but discard error has already occurred. Don't read"))
+			Expect(err.Error()).To(Equal("5 bytes to discard, but discard error has already occurred. Skipping read."))
 		})
 	})
 })
diff --git a/helper/restore_helper.go b/helper/restore_helper.go
index 7196e8ead..a0374fd03 100644
--- a/helper/restore_helper.go
+++ b/helper/restore_helper.go
@@ -111,7 +111,7 @@ func (r *RestoreReader) discardData(num int64) (int64, error) {
 	}
 
 	if r.discardErr {
-		err := fmt.Errorf("%d bytes to discard, but discard error has already occurred. Don't read", num)
+		err := fmt.Errorf("%d bytes to discard, but discard error has already occurred. Skipping read.", num)
 		logVerbose(err.Error())
 		return 0, err
 	}
@@ -137,7 +137,7 @@ func (r *RestoreReader) copyData(num int64) (int64, error) {
 		bytesRead, err = io.CopyN(writer, r.bufReader, num)
 	case SUBSET:
 		if r.discardErr {
-			err := fmt.Errorf("%d bytes to copy, but discard error has already occurred. Don't read", num)
+			err := fmt.Errorf("%d bytes to copy, but discard error has already occurred. Skipping read.", num)
 			logVerbose(err.Error())
 			return 0, err
 		}

From 3154bf63718e209ef02c6df0578762a4afc5c348 Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Tue, 16 Sep 2025 12:57:03 +0300
Subject: [PATCH 43/46] Add test for discard error. Rename discarded to
 discardedCount

---
 helper/helper_test.go | 38 +++++++++++++++++++++++++++++++++-----
 1 file changed, 33 insertions(+), 5 deletions(-)

diff --git a/helper/helper_test.go b/helper/helper_test.go
index b68e71a7d..649a8a264 100644
--- a/helper/helper_test.go
+++ b/helper/helper_test.go
@@ -18,9 +18,10 @@ import (
 )
 
 var (
-	testDir     = "/tmp/helper_test/20180101/20180101010101"
-	testTocFile = fmt.Sprintf("%s/test_toc.yaml", testDir)
-	discarded   int64
+	testDir        = "/tmp/helper_test/20180101/20180101010101"
+	testTocFile    = fmt.Sprintf("%s/test_toc.yaml", testDir)
+	discardedCount int64
+	discardErr     error
 )
 
 type restoreReaderTestImpl struct {
@@ -52,7 +53,11 @@ func (r *restoreReaderTestImpl) getReaderType() ReaderType {
 }
 
 func (r *restoreReaderTestImpl) discardData(num int64) (int64, error) {
-	discarded += num
+	if discardErr != nil {
+		return 0, discardErr
+	}
+
+	discardedCount += num
 	return num, nil
 }
 
@@ -486,7 +491,30 @@ var _ = Describe("helper tests", func() {
 			helper := newHelperTest(oidBatch, expectedScenario)
 			err := doRestoreAgentInternal(helper)
 			Expect(err).ToNot(HaveOccurred())
-			Expect(discarded).To(Equal(int64(18)))
+			Expect(discardedCount).To(Equal(int64(18)))
+		})
+		It("discard error data if skip file is discovered with single datafile", func() {
+			discardErr = io.EOF
+			*singleDataFile = true
+			*isResizeRestore = false
+			*tocFile = testTocFile
+
+			writeTestTOC(testTocFile)
+			defer func() {
+				_ = os.Remove(*tocFile)
+			}()
+
+			oidBatch := []oidWithBatch{
+				{1 /* The first oid from TOC */, 0},
+			}
+
+			expectedScenario := []helperTestStep{
+				{"mock_1_0", false, 1, true, "Can not open pipe for table 1, check_skip_file shall called, skip file exists"},
+			}
+
+			helper := newHelperTest(oidBatch, expectedScenario)
+			err := doRestoreAgentInternal(helper)
+			Expect(err).To(Equal(discardErr))
 		})
 		It("calls Wait in waitForPlugin doRestoreAgent for single data file", func() {
 			*singleDataFile = true

From 90420b9f4c30ba1ec5b12db14515949edd8f1573 Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Tue, 16 Sep 2025 12:59:03 +0300
Subject: [PATCH 44/46] Rename

---
 helper/helper_test.go | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/helper/helper_test.go b/helper/helper_test.go
index 649a8a264..d89f03ce4 100644
--- a/helper/helper_test.go
+++ b/helper/helper_test.go
@@ -20,7 +20,7 @@ import (
 var (
 	testDir        = "/tmp/helper_test/20180101/20180101010101"
 	testTocFile    = fmt.Sprintf("%s/test_toc.yaml", testDir)
-	discardedCount int64
+	discardedBytes int64
 	discardErr     error
 )
 
@@ -57,7 +57,7 @@ func (r *restoreReaderTestImpl) discardData(num int64) (int64, error) {
 		return 0, discardErr
 	}
 
-	discardedCount += num
+	discardedBytes += num
 	return num, nil
 }
 
@@ -491,7 +491,7 @@ var _ = Describe("helper tests", func() {
 			helper := newHelperTest(oidBatch, expectedScenario)
 			err := doRestoreAgentInternal(helper)
 			Expect(err).ToNot(HaveOccurred())
-			Expect(discardedCount).To(Equal(int64(18)))
+			Expect(discardedBytes).To(Equal(int64(18)))
 		})
 		It("discard error data if skip file is discovered with single datafile", func() {
 			discardErr = io.EOF

From 4c4c51743152e31c5089f4e7191db9b8a8e5b023 Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Tue, 16 Sep 2025 13:03:17 +0300
Subject: [PATCH 45/46] Clear discardErr

---
 helper/helper_test.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/helper/helper_test.go b/helper/helper_test.go
index d89f03ce4..63ee09ebc 100644
--- a/helper/helper_test.go
+++ b/helper/helper_test.go
@@ -515,6 +515,7 @@ var _ = Describe("helper tests", func() {
 			helper := newHelperTest(oidBatch, expectedScenario)
 			err := doRestoreAgentInternal(helper)
 			Expect(err).To(Equal(discardErr))
+			discardErr = nil
 		})
 		It("calls Wait in waitForPlugin doRestoreAgent for single data file", func() {
 			*singleDataFile = true

From 3a54c484b68c84935acd112c5006dbc808903dcc Mon Sep 17 00:00:00 2001
From: Andrey Sokolov <a.sokolov@arenadata.io>
Date: Tue, 16 Sep 2025 13:23:31 +0300
Subject: [PATCH 46/46] Move global variables to struct

---
 helper/helper_test.go | 23 +++++++++++------------
 1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/helper/helper_test.go b/helper/helper_test.go
index 63ee09ebc..fa10d7686 100644
--- a/helper/helper_test.go
+++ b/helper/helper_test.go
@@ -18,14 +18,14 @@ import (
 )
 
 var (
-	testDir        = "/tmp/helper_test/20180101/20180101010101"
-	testTocFile    = fmt.Sprintf("%s/test_toc.yaml", testDir)
-	discardedBytes int64
-	discardErr     error
+	testDir     = "/tmp/helper_test/20180101/20180101010101"
+	testTocFile = fmt.Sprintf("%s/test_toc.yaml", testDir)
 )
 
 type restoreReaderTestImpl struct {
-	waitCount int
+	waitCount      int
+	discardedBytes int64
+	discardErr     error
 }
 
 func (r *restoreReaderTestImpl) waitForPlugin() error {
@@ -53,11 +53,11 @@ func (r *restoreReaderTestImpl) getReaderType() ReaderType {
 }
 
 func (r *restoreReaderTestImpl) discardData(num int64) (int64, error) {
-	if discardErr != nil {
-		return 0, discardErr
+	if r.discardErr != nil {
+		return 0, r.discardErr
 	}
 
-	discardedBytes += num
+	r.discardedBytes += num
 	return num, nil
 }
 
@@ -491,10 +491,9 @@ var _ = Describe("helper tests", func() {
 			helper := newHelperTest(oidBatch, expectedScenario)
 			err := doRestoreAgentInternal(helper)
 			Expect(err).ToNot(HaveOccurred())
-			Expect(discardedBytes).To(Equal(int64(18)))
+			Expect(helper.restoreData.discardedBytes).To(Equal(int64(18)))
 		})
 		It("discard error data if skip file is discovered with single datafile", func() {
-			discardErr = io.EOF
 			*singleDataFile = true
 			*isResizeRestore = false
 			*tocFile = testTocFile
@@ -513,9 +512,9 @@ var _ = Describe("helper tests", func() {
 			}
 
 			helper := newHelperTest(oidBatch, expectedScenario)
+			helper.restoreData.discardErr = io.EOF
 			err := doRestoreAgentInternal(helper)
-			Expect(err).To(Equal(discardErr))
-			discardErr = nil
+			Expect(err).To(Equal(io.EOF))
 		})
 		It("calls Wait in waitForPlugin doRestoreAgent for single data file", func() {
 			*singleDataFile = true