reduce NOWAIT usage to tables with unique keys for foreign key plans (#…

…14772)
vitessio · Dec 20, 2023 · c4b275c · c4b275c
1 parent ed5e67f
commit c4b275c
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Showing 5 changed files with 107 additions and 93 deletions.
diff --git a/go/vt/vtgate/planbuilder/operators/delete.go b/go/vt/vtgate/planbuilder/operators/delete.go
@@ -110,7 +110,7 @@ func createOperatorFromDelete(ctx *plancontext.PlanningContext, deleteStmt *sqlp
 		panic(vterrors.VT12001("foreign keys management at vitess with limit"))
 	}
 
-	return createFkCascadeOpForDelete(ctx, delOp, delClone, childFks)
+	return createFkCascadeOpForDelete(ctx, delOp, delClone, childFks, vindexTable)
 }
 
 func createDeleteOperator(ctx *plancontext.PlanningContext, del *sqlparser.Delete) Operator {
@@ -193,7 +193,7 @@ func updateQueryGraphWithSource(ctx *plancontext.PlanningContext, input Operator
 	return vTbl
 }
 
-func createFkCascadeOpForDelete(ctx *plancontext.PlanningContext, parentOp Operator, delStmt *sqlparser.Delete, childFks []vindexes.ChildFKInfo) Operator {
+func createFkCascadeOpForDelete(ctx *plancontext.PlanningContext, parentOp Operator, delStmt *sqlparser.Delete, childFks []vindexes.ChildFKInfo, deletedTbl *vindexes.Table) Operator {
 	var fkChildren []*FkChild
 	var selectExprs []sqlparser.SelectExpr
 	for _, fk := range childFks {
@@ -210,7 +210,7 @@ func createFkCascadeOpForDelete(ctx *plancontext.PlanningContext, parentOp Opera
 		fkChildren = append(fkChildren,
 			createFkChildForDelete(ctx, fk, offsets))
 	}
-	selectionOp := createSelectionOp(ctx, selectExprs, delStmt.TableExprs, delStmt.Where, nil, nil, sqlparser.ForUpdateLockNoWait)
+	selectionOp := createSelectionOp(ctx, selectExprs, delStmt.TableExprs, delStmt.Where, nil, nil, getUpdateLock(deletedTbl))
 
 	return &FkCascade{
 		Selection: selectionOp,

diff --git a/go/vt/vtgate/planbuilder/operators/update.go b/go/vt/vtgate/planbuilder/operators/update.go
@@ -255,7 +255,7 @@ func createFKCascadeOp(ctx *plancontext.PlanningContext, parentOp Operator, updS
 		fkChildren = append(fkChildren, fkChild)
 	}
 
-	selectionOp := createSelectionOp(ctx, selectExprs, updStmt.TableExprs, updStmt.Where, updStmt.OrderBy, nil, sqlparser.ForUpdateLockNoWait)
+	selectionOp := createSelectionOp(ctx, selectExprs, updStmt.TableExprs, updStmt.Where, updStmt.OrderBy, nil, getUpdateLock(updatedTable))
 
 	return &FkCascade{
 		Selection: selectionOp,
@@ -658,7 +658,21 @@ func createFkVerifyOpForParentFKForUpdate(ctx *plancontext.PlanningContext, upda
 		sqlparser.NewWhere(sqlparser.WhereClause, whereCond),
 		nil,
 		sqlparser.NewLimitWithoutOffset(1),
-		sqlparser.ForShareLockNoWait)
+		getVerifyLock(updatedTable))
+}
+
+func getVerifyLock(vTbl *vindexes.Table) sqlparser.Lock {
+	if len(vTbl.UniqueKeys) > 0 {
+		return sqlparser.ForShareLockNoWait
+	}
+	return sqlparser.ForShareLock
+}
+
+func getUpdateLock(vTbl *vindexes.Table) sqlparser.Lock {
+	if len(vTbl.UniqueKeys) > 0 {
+		return sqlparser.ForUpdateLockNoWait
+	}
+	return sqlparser.ForUpdateLock
 }
 
 // Each child foreign key constraint is verified by a join query of the form:
@@ -728,7 +742,7 @@ func createFkVerifyOpForChildFKForUpdate(ctx *plancontext.PlanningContext, updat
 		sqlparser.NewWhere(sqlparser.WhereClause, whereCond),
 		nil,
 		sqlparser.NewLimitWithoutOffset(1),
-		sqlparser.ForShareLockNoWait)
+		getVerifyLock(updatedTable))
 }
 
 // nullSafeNotInComparison is used to compare the child columns in the foreign key constraint aren't the same as the updateExpressions exactly.