fix: handle PostgreSQL identifier quoting in partial index predicate comparison by jay-l-e-e · Pull Request #5788 · prisma/prisma-engines

jay-l-e-e · 2026-03-07T11:53:21Z

Description

Problem

After #5780, partial indexes with object literal where clauses are still recreated on every migration when predicates contain multiple conditions. PostgreSQL's pg_get_expr() returns unquoted identifiers for lowercase column names (postcode), while Prisma generates quoted identifiers ("postcode"). The AST comparison treats these as different, causing needless drop+recreate cycles.

-- Prisma generates:
("deletedAt" IS NULL AND "postcode" IS NOT NULL)

-- pg_get_expr() returns:
((("deletedAt" IS NULL) AND (postcode IS NOT NULL)))

Solution

Extend exprs_semantically_eq to treat quoted and unquoted identifiers as equivalent when the unquoted form is a valid PostgreSQL identifier. Uses sqlparser with PostgreSqlDialect to verify that the identifier value can be safely used without quotes (i.e., it's not a reserved keyword and follows identifier rules).

Changes

PG schema_differ.rs — Added identifier quoting comparison in exprs_semantically_eq; checks if "foo" and foo refer to the same column by re-parsing with sqlparser
partial.rs — Regression test for object literal predicates with null and not: null conditions

Summary by CodeRabbit

Bug Fixes
- Improved PostgreSQL schema comparison to more robustly treat identifiers as equivalent across quote styles and within expressions.
Tests
- Added an idempotency test for Postgres partial indexes using object-literal filters with null and not-null conditions.

…n partial index predicate comparison

coderabbitai · 2026-03-07T11:53:39Z

No actionable comments were generated in the recent review. 🎉

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📥 Commits

Reviewing files that changed from the base of the PR and between 0953f51 and c75b823.

📒 Files selected for processing (1)

schema-engine/connectors/sql-schema-connector/src/flavour/postgres/schema_differ.rs

Walkthrough

Adds semantic identifier comparison to the Postgres schema differ to treat quoted and unquoted identifiers as equivalent in predicate ASTs, and adds a Postgres test ensuring a partial index with an object-literal where clause is idempotent across repeated pushes.

Changes

Cohort / File(s)	Summary
Postgres Schema Differ Enhancement `schema-engine/connectors/sql-schema-connector/src/flavour/postgres/schema_differ.rs`	Adds private `fn idents_semantically_eq(a: &Ident, b: &Ident) -> bool`; extends `exprs_semantically_eq` to handle `Identifier` and `CompoundIdentifier` by delegating to the new helper; refactors `pg_predicates_semantically_equal` imports and comparison paths to use the identifier-aware logic.
Partial Index Tests `schema-engine/sql-migration-tests/tests/migrations/indexes/partial.rs`	Adds test `partial_index_object_literal_null_and_not_null_is_idempotent_postgres` (Postgres-only, excludes CockroachDB, enables `partialIndexes`) verifying idempotence of partial index with object-literal where clause across consecutive pushes.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 40.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	Title accurately describes the main change: adding PostgreSQL identifier quoting handling in partial index predicate comparison, matching the core objective.
Linked Issues check	✅ Passed	Code changes directly address issue `#5787`: new idents_semantically_eq function handles quoted vs unquoted identifier comparison [`#5787`], and regression test validates the fix [`#5787`].
Out of Scope Changes check	✅ Passed	All changes are directly scoped to the linked issue: identifier comparison logic in schema_differ.rs and a regression test in partial.rs.

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jay-l-e-e · 2026-03-07T11:59:46Z

Hi @jacek-prisma, Please review these changes! Thank you.

codspeed-hq · 2026-03-09T09:06:53Z

Merging this PR will not alter performance

✅ 11 untouched benchmarks
⏩ 11 skipped benchmarks¹

_{Comparing jay-l-e-e:fix/partial-index-pg-identifier-quoting (c75b823) with main (ab73dcf)}

11 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

schema-engine/connectors/sql-schema-connector/src/flavour/postgres/schema_differ.rs

fix: treat quoted and unquoted PostgreSQL identifiers as equivalent i…

0953f51

…n partial index predicate comparison

jay-l-e-e mentioned this pull request Mar 7, 2026

fix: use AST comparison for partial index predicates on PostgreSQL and MSSQL #5780

Merged

jacek-prisma reviewed Mar 9, 2026

View reviewed changes

schema-engine/connectors/sql-schema-connector/src/flavour/postgres/schema_differ.rs Outdated Show resolved Hide resolved

refactor: simplify identifier validation in idents_semantically_eq

c75b823

jacek-prisma approved these changes Mar 9, 2026

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jacek-prisma merged commit 0f1690a into prisma:main Mar 9, 2026
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fix: handle PostgreSQL identifier quoting in partial index predicate comparison#5788

fix: handle PostgreSQL identifier quoting in partial index predicate comparison#5788
jacek-prisma merged 2 commits intoprisma:mainfrom
jay-l-e-e:fix/partial-index-pg-identifier-quoting

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Description

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Solution

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Summary by CodeRabbit

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Walkthrough

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Merging this PR will not alter performance

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jay-l-e-e commented Mar 7, 2026 •

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