make SelectMergeRule greedily merge all child selects

[g31pranjal]

No description provided.

[github-actions]

📊 Metrics Diff Analysis Report

Summary

• New queries: 0
• Dropped queries: 0
• Plan changed + metrics changed: 23
• Plan unchanged + metrics changed: 32

ℹ️ About this analysis

This automated analysis compares query planner metrics between the base branch and this PR. It categorizes changes into:

• New queries: Queries added in this PR
• Dropped queries: Queries removed in this PR. These should be reviewed to ensure we are not losing coverage.
• Plan changed + metrics changed: The query plan has changed along with planner metrics.
• Metrics only changed: Same plan but different metrics

The last category in particular may indicate planner regressions that should be investigated.

Plan and Metrics Changed

These queries experienced both plan and metrics changes. This generally indicates that there was some planner change
that means the planning for this query may be substantially different. Some amount of query plan metrics change is expected,
but the reviewer should still validate that these changes are not excessive.

Total: 23 queries

Statistical Summary (Plan and Metrics Changed)

task_count:

• Average change: +54.0
• Average regression: +54.0
• Median change: +54
• Median regression: +54
• Standard deviation: 0.0
• Standard deviation of regressions: 0.0
• Range: +54 to +54
• Range of regressions: +54 to +54
• Queries changed: 1
• Queries regressed: 1

transform_count:

• Average change: +10.0
• Average regression: +10.0
• Median change: +10
• Median regression: +10
• Standard deviation: 0.0
• Standard deviation of regressions: 0.0
• Range: +10 to +10
• Range of regressions: +10 to +10
• Queries changed: 1
• Queries regressed: 1

transform_yield_count:

• Average change: +4.0
• Average regression: +4.0
• Median change: +4
• Median regression: +4
• Standard deviation: 0.0
• Standard deviation of regressions: 0.0
• Range: +4 to +4
• Range of regressions: +4 to +4
• Queries changed: 1
• Queries regressed: 1

insert_new_count:

• Average change: -1.5
• Median change: -1
• Standard deviation: 1.2
• Range: -6 to -1
• Queries changed: 23
• No regressions! 🎉

insert_reused_count:

• Average change: -1.0
• Median change: -1
• Standard deviation: 0.0
• Range: -1 to -1
• Queries changed: 1
• No regressions! 🎉

There were no queries with significant regressions detected.

Minor Changes (Plan and Metrics Changed)

In addition, there were 23 queries with minor changes.

Only Metrics Changed

These queries experienced only metrics changes without any plan changes. If these metrics have substantially changed,
then a planner change has been made which affects planner performance but does not correlate with any new outcomes,
which could indicate a regression.

Total: 32 queries

Statistical Summary (Only Metrics Changed)

task_count:

• Average change: -107.0
• Median change: -22
• Standard deviation: 85.0
• Range: -192 to -22
• Queries changed: 4
• No regressions! 🎉

transform_yield_count:

• Average change: -9.0
• Median change: -2
• Standard deviation: 7.0
• Range: -16 to -2
• Queries changed: 4
• No regressions! 🎉

insert_new_count:

• Average change: -12.8
• Median change: -2
• Standard deviation: 38.3
• Range: -160 to -1
• Queries changed: 32
• No regressions! 🎉

insert_reused_count:

• Average change: +9.0
• Average regression: +9.0
• Median change: +16
• Median regression: +16
• Standard deviation: 7.0
• Standard deviation of regressions: 7.0
• Range: +2 to +16
• Range of regressions: +2 to +16
• Queries changed: 4
• Queries regressed: 4

There were no queries with significant regressions detected.

Minor Changes (Only Metrics Changed)

In addition, there were 32 queries with minor changes.