[pyramation]

Summary

ALTER STATISTICS

• RenameStmt with OBJECT_STATISTIC_EXT threw Unsupported RenameStmt renameType. It now emits ALTER STATISTICS [schema.]name RENAME TO new, with the qualified name quoted.
• AlterStatsStmt dropped IF EXISTS (missing_ok), emitted invalid SET STATISTICS with no value for SET STATISTICS DEFAULT (the PG18 AST has no stxstattarget), and did not quote names.

Operator names. The schema part of a qualified operator was never quoted, and the operator symbol was emitted unchecked. Before → after:

input	before	after
a OPERATOR("My Schema".+) b	OPERATOR(My Schema.+) (syntax error)	unchanged
a OPERATOR("S".=) ANY (...)	OPERATOR(S.=) (a different schema)	unchanged
CREATE OPERATOR ... COMMUTATOR = OPERATOR("My Schema".===)	Commutator = "My Schema", "==="	Commutator = OPERATOR("My Schema".===)
ALTER OPERATOR ... SET (COMMUTATOR = OPERATOR("My Schema".===))	commutator = 'My Schema, ==='	commutator = OPERATOR("My Schema".===)
COMMENT ON OPERATOR "My Schema".=== (int, int)	COMMENT ON OPERATOR My Schema(int, int)	unchanged
opclass/opfamily OPERATOR 1 "S".< (int, int)	S.<(int, int)	"S".<(int, int)
EXCLUDE (c WITH OPERATOR("S".&&))	c WITH S (syntax error)	c WITH OPERATOR("S".&&)

All of these now go through one helper, qualifiedOperatorName(names): it quotes each schema part with QuoteUtils.quoteIdentifier and checks the symbol. deparseOperatorName wraps qualified names in OPERATOR(...). ObjectWithArgs takes an isOperator flag, which defaults to context.objtype === 'OBJECT_OPERATOR' and is passed by AlterOperatorStmt and opclass operator items.

The symbol check throws Invalid operator name for any name that would not lex back as the same single operator token:

• characters outside ~!@#^&|?+-*/%<>=`
• names containing -- or /*
• !=, which the lexer rewrites to <>
• =>
• 64 or more characters
• multi-character names ending in +/- that don't contain one of ~!@#^&|?%, e.g. +-, which lexes as + -`

Before this change those names were emitted as-is, so the SQL silently reparsed as a different expression.

Tests

• New kitchen-sink fixtures misc/alter-statistics.sql and misc/operator-names.sql, regenerated with npm run kitchen-sink.
• __tests__/misc/operator-names.test.ts uses hand-built ASTs, because the parser can never produce an invalid operator name. It covers the rejected names and some valid edge cases (~-, @-@, a quoted schema).
• Before the fix (old src/deparser.ts checked out): both fixture tests and 10/13 of the hand-built cases failed, with Unsupported RenameStmt renameType: OBJECT_STATISTIC_EXT, syntax error at or near "Schema", or Received function did not throw. After the fix all 15 pass.
• Full suites: deparser 763/763, transform 250/250, plpgsql-deparser 115/115, transform-ast 1443/1443. tsc is clean and lint reports 0 errors.

This is independent of #368 and #369.

Link to Devin session: https://app.devin.ai/sessions/cb07c6509db64478af655f52611468f4
Open in Devin Desktop: https://app.devin.ai/desktop/session/cb07c6509db64478af655f52611468f4?variant=devin
Requested by: @pyramation

[devin-ai-integration]

I'll fix CI failures and address comments from users with write access. I'll skip comments containing "(aside)".

• Disable automatic comment, CI, and merge conflict monitoring

[tenki-reviewer]

Review complete. 🟡 1 medium

💬 Inline comments (1)

• 🟡 % wrongly accepted in operators ending in +/- — deparser.ts:991

---

The change teaches the deparser to emit qualified operator references (OPERATOR(schema.op)) and validate operator symbol names against PostgreSQL lexer rules, and extends RenameStmt/AlterStatsStmt handling for statistics objects including IF EXISTS and SET STATISTICS DEFAULT.

Files	Change
packages/deparser/src/deparser.ts	Adds isValidOperatorSymbol/qualifiedOperatorName/deparseOperatorName helpers, wires operator-name lists through A_Expr, CommentStmt, DefElem commutator/negator, DefineStmt, and ObjectWithArgs; adds OBJECT_STATISTIC_EXT and IF EXISTS/DEFAULT handling for ALTER STATISTICS.
__fixtures__/kitchen-sink/misc/{operator-names,alter-statistics}.sql, __fixtures__/generated/generated.json	New fixtures covering 18 operator-name cases and 9 ALTER STATISTICS cases.
packages/deparser/__tests__/*	Kitchen-sink tests for the two new fixture sets plus a unit test for operator-name validation.

_{Reviewed commit: e2c6d77}

[tenki-reviewer]

This PR adds operator-name validation and qualified OPERATOR(schema.op) deparsing plus ALTER STATISTICS support to the deparser, backed by new kitchen-sink fixtures and tests.

Key findings

• 🟡 % wrongly accepted in operators ending in +/- — deparser.ts:991

[tenki-reviewer]

🟡 bug · medium

% wrongly accepted in operators ending in +/-

isValidOperatorSymbol includes % in the exception class /[~!@#^&|?%]/that legalizes multi-character operators ending in+or-(packages/deparser/src/deparser.ts:991). PostgreSQL's lexer only allows such operators when they contain at least one of~ ! @ # ^ & | ` ?—%does not qualify. A name like%+` therefore passes validation and is deparsed, but the emitted SQL is rejected by the real PostgreSQL parser, breaking the round-trip guarantee this check was added to enforce.

📋 Prompt for AI Agents

In packages/deparser/src/deparser.ts at line 991, change the trailing +/- exception regex in isValidOperatorSymbol from /[~!@#^&|?%]/to/[~!@#^&|?]/. PostgreSQL's lexer only allows a multi-character operator ending in + or - when it contains one of ~ ! @ # ^ & | ? — % does not qualify, so the current code accepts invalid operators like%+` that PostgreSQL will reject on reparse.

[devin-ai-integration]

Folded into #371