fix: preserve INCLUDE columns in CREATE INDEX CONCURRENTLY (#508)

[tianzhou]

Summary

Fixes #508.

The generateIndexSQL in rewrite.go (used exclusively for CREATE INDEX CONCURRENTLY statements) was a duplicate of the canonical version in index.go but missing the INCLUDE clause. This caused covering indexes to lose their non-key columns when added to existing tables, creating an infinite plan loop.

• Added INCLUDE columns emission between the key columns and NULLS NOT DISTINCT
• Fixed operator class vs direction ordering to match the canonical version (operator class before direction, per PostgreSQL syntax)
• Root cause: two separate generateIndexSQL implementations drifted apart

Test plan

• New fixture online/issue_508_include_columns_concurrent_index — adds a covering index (a) INCLUDE (b) to an existing table
• Diff test passes (non-concurrent output preserves INCLUDE)
• Integration test passes (concurrent output preserves INCLUDE)
• Full diff test suite passes — no regressions

🤖 Generated with Claude Code

[greptile-apps]

Greptile Summary

This PR fixes concurrent covering-index generation. The main changes are:

• Adds INCLUDE columns to the online CREATE INDEX CONCURRENTLY rewrite path.
• Emits operator classes before index direction to match PostgreSQL syntax.
• Adds an online regression fixture for (a) INCLUDE (b) indexes.

Confidence Score: 5/5

This looks safe to merge.

• No blocking issues found in the changed code.

Important Files Changed

Filename	Overview
internal/plan/rewrite.go	Updates concurrent index SQL generation to preserve INCLUDE columns and match the canonical operator-class ordering.
testdata/diff/online/issue_508_include_columns_concurrent_index/diff.sql	Adds expected diff output for creating a covering index with INCLUDE columns.
testdata/diff/online/issue_508_include_columns_concurrent_index/new.sql	Adds the desired schema fixture containing the covering index.
testdata/diff/online/issue_508_include_columns_concurrent_index/old.sql	Adds the baseline schema fixture before the covering index exists.
testdata/diff/online/issue_508_include_columns_concurrent_index/plan.json	Adds expected JSON plan output with concurrent covering-index creation.
testdata/diff/online/issue_508_include_columns_concurrent_index/plan.sql	Adds expected SQL plan output with the concurrent covering-index statement and wait query.
testdata/diff/online/issue_508_include_columns_concurrent_index/plan.txt	Adds expected text plan output for the online covering-index fixture.

_{Reviews (1): Last reviewed commit: "fix: preserve INCLUDE columns in CREATE ..." | Re-trigger Greptile}

[Copilot]

Pull request overview

This PR fixes a drift bug in the online-plan rewrite path for CREATE INDEX CONCURRENTLY, ensuring covering indexes keep their INCLUDE columns (preventing repeated “rebuild index” loops in subsequent plans).

Changes:

• Emit INCLUDE (...) columns in the internal/plan/rewrite.go concurrent index SQL generator.
• Align index column syntax ordering with PostgreSQL grammar (operator class before sort direction).
• Add a new online diff fixture (issue_508_include_columns_concurrent_index) validating concurrent index creation preserves INCLUDE.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
testdata/diff/online/issue_508_include_columns_concurrent_index/plan.txt	New expected plan output showing CREATE INDEX CONCURRENTLY ... INCLUDE (...) plus wait step.
testdata/diff/online/issue_508_include_columns_concurrent_index/plan.sql	New SQL fixture asserting concurrent index creation includes INCLUDE.
testdata/diff/online/issue_508_include_columns_concurrent_index/plan.json	New JSON plan fixture verifying the emitted SQL includes INCLUDE.
testdata/diff/online/issue_508_include_columns_concurrent_index/old.sql	Fixture “before” state table definition (no index).
testdata/diff/online/issue_508_include_columns_concurrent_index/new.sql	Fixture “desired” state adding covering index with INCLUDE.
testdata/diff/online/issue_508_include_columns_concurrent_index/diff.sql	Fixture diff output for non-concurrent CREATE INDEX ... INCLUDE (...).
internal/plan/rewrite.go	Fix concurrent index SQL generation to preserve INCLUDE columns and correct column clause ordering.

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