Add a dolt_preview_merge_conflicts_summary table function

[tbantle22]

This table function shows which tables are conflicting between two branches and how many data and/or schema conflicts there are for each table

[Copilot]

Pull Request Overview

This PR adds a new dolt_preview_merge_conflicts_summary table function to report data and schema conflicts between branches, wires it into the engine and test harness, and updates merge logic to support the new functionality.

• Register PreviewMergeConflictsSummaryTableFunction and integrate it into SQL engine and tests
• Introduce GetNewValueMerger, Prolly‐backed row accessors, and expose SchemaMerge on TableMerger
• Rename internal newValueMerger/tryMerge to public NewValueMerger/TryMerge and update call sites

Reviewed Changes

Copilot reviewed 19 out of 19 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
merge/merge_rows.go	Added Prolly map helpers and GetNewValueMerger / SchemaMerge
merge/merge_rows.go (imports)	Missing import for durable in rowsFromTable
merge/merge_prolly_rows.go	Updated calls to NewValueMerger and TryMerge
merge/row_merge_test.go	Updated tests to use NewValueMerger / TryMerge
sqle/dtablefunctions/init.go	Registered new table function
sqle/enginetest/*	Bulk additions of select * from dolt_preview_merge_conflicts_summary assertions
sqle/enginetest/dolt_engine_tests.go and .go	Added harness runners and tests for preview conflict function
.github/workflows/merge-perf.yaml	Fixed typo in comment

Comments suppressed due to low confidence (2)

go/libraries/doltcore/sqle/enginetest/dolt_queries_schema_merge.go:46

• The table function returns uint64 counters, so using uint here may cause a type mismatch in the test. Change these literals to uint64(1) and uint64(0) to match the function's return types.

Expected: []sql.Row{{"t", uint(1), uint(0)}}

go/libraries/doltcore/merge/merge_rows.go:96

• The code references durable.ProllyMapFromIndex but there is no import for the durable package. Add the appropriate import to resolve this symbol and ensure compilation succeeds.

rows, err := durable.ProllyMapFromIndex(rd)

[coffeegoddd]

@tbantle22 DOLT

comparing_percentages
100.000000 to 100.000000

version	result	total
2900f6c	ok	5937457

version	total_tests
2900f6c	5937457

correctness_percentage
100.0

[coffeegoddd]

@coffeegoddd DOLT

comparing_percentages
100.000000 to 100.000000

version	result	total
cdc4b9e	ok	5937457

version	total_tests
cdc4b9e	5937457

correctness_percentage
100.0

[coffeegoddd]

@tbantle22 DOLT

comparing_percentages
100.000000 to 100.000000

version	result	total
95ac4e2	ok	5937457

version	total_tests
95ac4e2	5937457

correctness_percentage
100.0

[coffeegoddd]

@tbantle22 DOLT

comparing_percentages
100.000000 to 100.000000

version	result	total
3b800c0	ok	5937457

version	total_tests
3b800c0	5937457

correctness_percentage
100.0

[coffeegoddd]

@tbantle22 DOLT

comparing_percentages
100.000000 to 100.000000

version	result	total
efea9ed	ok	5937457

version	total_tests
efea9ed	5937457

correctness_percentage
100.0

[coffeegoddd]

@tbantle22 DOLT

comparing_percentages
100.000000 to 100.000000

version	result	total
3a5dcb3	ok	5937457

version	total_tests
3a5dcb3	5937457

correctness_percentage
100.0