Add reserved procedures/functions namespaces and naming rules (#320)

Author: NataliaIvakina

modules/ROOT/pages/extending-neo4j/aggregation-functions.adoc

@@ -32,6 +32,12 @@ An aggregator class contains one method annotated with `@UserAggregationUpdate`
 The method annotated with `@UserAggregationUpdate` will be called multiple times and enables the class to aggregate data.
 When the aggregation is done, the method annotated with `@UserAggregationResult` will be called once and the result of the aggregation will be returned.
 
+Particular things to note:
+
+* All functions are annotated with `@UserAggregationFunction`.
+* The aggregation function name must be namespaced and is not allowed in reserved namespaces.
+* If a user-defined aggregation function is registered with the same name as a built-in function in a deprecated namespace, the built-in function is shadowed.
+
 See xref:extending-neo4j/values-and-types.adoc[] for details on values and types.
 
 For more details, see the Neo4j Javadocs for link:{org-neo4j-procedure-UserAggregationFunction}[`org.neo4j.procedure.UserAggregationFunction`^].
@@ -132,3 +138,53 @@ public class LongestStringTest
 }
 ----
 
+
+[[reserved-function-namespaces]]
+== Reserved function namespaces
+
+
+List of reserved function namespaces and names::
+
+* *                          
+* date
+* date.realtime
+* date.statement
+* date.transaction
+* date.truncate
+* datetime
+* datetime.fromepoch
+* datetime.fromepochmillis
+* datetime.realtime
+* datetime.statement
+* datetime.transaction
+* datetime.truncate
+* db.nameFromElementId
+* duration
+* duration.between
+* duration.inDays
+* duration.inMonths
+* duration.inSeconds
+* graph.byElementId
+* graph.byName
+* graph.names
+* graph.propertiesByName
+* localdatetime
+* localdatetime.realtime
+* localdatetime.statement
+* localdatetime.transaction
+* localdatetime.truncate
+* localtime
+* localtime.realtime
+* localtime.statement
+* localtime.transaction
+* localtime.truncate
+* point.distance
+* point.withinBBox
+* time
+* time.realtime
+* time.statement
+* time.transaction
+* time.truncate
+* vector.similarity.cosine
+* vector.similarity.euclidean
+

modules/ROOT/pages/extending-neo4j/functions.adoc

@@ -30,6 +30,12 @@ RETURN org.neo4j.examples.join(collect(p.names))
 User-defined functions are created similarly to how procedures are created.
 But unlike procedures, they are annotated with `@UserFunction` and return a single value instead of a stream of values.
 
+Particular things to note:
+
+* All functions are annotated with `@UserFunction`.
+* The function name must be namespaced and is not allowed in reserved namespaces.
+* If a function is registered with the same name as a built-in function in a deprecated namespace, the built-in function is shadowed.
+
 See xref:extending-neo4j/values-and-types.adoc[] for details on values and types.
 
 For more details, see the link:{org-neo4j-procedure-UserFunction}[Neo4j Javadocs for `org.neo4j.procedure.UserFunction`^].
@@ -120,3 +126,52 @@ public class JoinTest {
 }
 ----
 
+
+[[reserved-function-namespaces]]
+== Reserved function namespaces
+
+List of reserved function namespaces::
+
+* *
+* date
+* date.realtime
+* date.statement
+* date.transaction
+* date.truncate
+* datetime
+* datetime.fromepoch
+* datetime.fromepochmillis
+* datetime.realtime
+* datetime.statement
+* datetime.transaction
+* datetime.truncate
+* db.nameFromElementId
+* duration
+* duration.between
+* duration.inDays
+* duration.inMonths
+* duration.inSeconds
+* graph.byElementId
+* graph.byName
+* graph.names
+* graph.propertiesByName
+* localdatetime
+* localdatetime.realtime
+* localdatetime.statement
+* localdatetime.transaction
+* localdatetime.truncate
+* localtime
+* localtime.realtime
+* localtime.statement
+* localtime.transaction
+* localtime.truncate
+* point.distance
+* point.withinBBox
+* time
+* time.realtime
+* time.statement
+* time.transaction
+* time.truncate
+* vector.similarity.cosine
+* vector.similarity.euclidean
+

modules/ROOT/pages/extending-neo4j/procedures.adoc

@@ -143,6 +143,8 @@ Particular things to note:
 * The procedure annotation can take three optional arguments: `name`, `mode`, and `eager`.
 ** `name` is used to specify a different name for the procedure than the default generated, which is `class.path.nameOfMethod`.
    If `mode` is specified, `name` must be specified as well.
+** `name` is not allowed in a reserved namespace, and having a `name` without a namespace is deprecated behavior.
+** If a procedure is registered with the same name as a built-in procedure in a deprecated namespace, the built-in procedure is shadowed.
 ** `mode` is used to declare the types of interactions that the procedure performs.
    A procedure fails if it attempts to execute database operations that violate its mode.
    The default `mode` is `READ`.
@@ -163,7 +165,7 @@ Particular things to note:
 MATCH (n)
 WHERE n.key = 'value'
 WITH n
-CALL deleteNeighbours(n, 'FOLLOWS')
+CALL example.deleteNeighbours(n, 'FOLLOWS')
 ----
 This query can delete some of the nodes that are matched by the Cypher query, and the `n.key` lookup will fail.
 Marking this procedure as `eager` prevents this from causing an error in Cypher code.
@@ -273,3 +275,24 @@ public class MyProcedures {
 }
 
 ----
+
+
+[[reserved-procedure-namespaces]]
+== Reserved procedure namespaces
+
+List of reserved procedure namespaces::
+
+* cdc.*
+* date.*
+* datetime.*
+* db.*
+* dbms.*
+* duration.*
+* graph.*
+* internal.*
+* localdatetime.*
+* localtime.*
+* time.*
+* tx.*
+* unsupported.*
+