Merge #130361

130361: workload/schemachange: add unique constraint hits duplicate key errors r=fqazi a=fqazi

Previously, the ALTER TABLE ADD UNIQUE CONSTRAINT operation could encounter duplicate key errors. This would occur because our scan query was not exhaustive enough. To address this and to help stabilize the workload, we will allow unique violations to be potential commit errors.

Fixes: #129909

Release note: None

Co-authored-by: Faizan Qazi <[email protected]>

Author: craig[bot]

pkg/workload/schemachange/operation_generator.go

@@ -400,6 +400,11 @@ func (og *operationGenerator) addUniqueConstraint(ctx context.Context, tx pgx.Tx
 
 	if !canApplyConstraint {
 		og.candidateExpectedCommitErrors.add(pgcode.UniqueViolation)
+	} else {
+		// Otherwise there is still a possibility for an error,
+		// so add it in the potential set, since our validation query
+		// above isn't exhaustive enough.
+		og.potentialCommitErrors.add(pgcode.UniqueViolation)
 	}
 
 	stmt.sql = fmt.Sprintf(