When re-executing a pausable portal, we re-call the connExecutor.execStmtInOpenState(). Originally, the logic in this function is expected to be run only once for each query, so we're not sure if they should be rerun for a portal. This home region savepoint part is an example, and we should confirm its usage.
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if enforceHomeRegion && ex.state.mu.txn.IsOpen() && isSelectStmt { |
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// Create a savepoint at a point before which rows were read so that we can |
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// roll back to it, which will allow the txn to be modified with a |
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// historical timestamp (so that the locality-optimized ops used for error |
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// reporting can run locally and not incur latency). This is currently only |
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// supported for SELECT statements. |
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var b strings.Builder |
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b.WriteString("enforce_home_region_sp") |
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// Add some unprintable ASCII characters to the name of the savepoint to |
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// decrease the likelihood of collision with a user-created savepoint. |
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b.WriteRune(rune(0x11)) |
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b.WriteRune(rune(0x12)) |
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b.WriteRune(rune(0x13)) |
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enforceHomeRegionSavepointName := tree.Name(b.String()) |
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s := &tree.Savepoint{Name: enforceHomeRegionSavepointName} |
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var event fsm.Event |
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var eventPayload fsm.EventPayload |
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if event, eventPayload, err = ex.execSavepointInOpenState(ctx, s, res); err != nil { |
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return event, eventPayload, err |
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} |
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|
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r = &tree.ReleaseSavepoint{Savepoint: enforceHomeRegionSavepointName} |
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rollbackSP = &tree.RollbackToSavepoint{Savepoint: enforceHomeRegionSavepointName} |
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defer func() { |
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// The default case is to roll back the internally-generated savepoint |
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// after every request. We only need it if a retryable "query has no home |
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// region" error occurs. |
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ex.execRelease(ctx, r, res) |
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}() |
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} |
Jira issue: CRDB-25869
Epic CRDB-25183