cockroachdb / cockroachdb/cockroach
sql/hints: failed hint causes prepared memo to always be invalidated
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A-plan-management
A-statement-hint
C-performance
T-sql-queries
- Dominant language
- Go
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Description
After preparing a memo with an injected statement hint fails, we set `usingHintInjection` [to false](https://github.com/cockroachdb/cockroach/blob/2d7256aebf3a9af6551df5ec35cb3f9a8e3100c2/pkg/sql/plan_opt.go#L71) and re-plan, caching the result. However, when the prepared memo is executed, we check for staleness with `usingHintInjection` [set to true,](https://github.com/cockroachdb/cockroach/blob/2d7256aebf3a9af6551df5ec35cb3f9a8e3100c2/pkg/sql/plan_opt.go#L315) which results in the memo being invalidated. We should either reuse the memo without hints, or not re-plan during prepare, since otherwise we're doing extra work for no reason.
Jira issue: CRDB-62381
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