vitessio/vitess · error

strict index ordering is unsupported

Error message

strict index ordering is unsupported

What it means

ErrStrictIndexOrderingUnsupported is returned when the requested diff operation requires strict preservation of index ordering, which the schemadiff engine does not support. Index comparison in Vitess is order-insensitive, so a diff that depends on exact index ordinality cannot be honored.

Source

Thrown at go/vt/schemadiff/errors.go:30

WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package schemadiff

import (
	"errors"
	"fmt"
	"strings"

	"vitess.io/vitess/go/sqlescape"
	"vitess.io/vitess/go/vt/sqlparser"
)

var (
	ErrEntityTypeMismatch             = errors.New("mismatched entity type")
	ErrStrictIndexOrderingUnsupported = errors.New("strict index ordering is unsupported")
	ErrUnexpectedDiffAction           = errors.New("unexpected diff action")
	ErrUnexpectedTableSpec            = errors.New("unexpected table spec")
	ErrExpectedCreateTable            = errors.New("expected a CREATE TABLE statement")
	ErrExpectedCreateView             = errors.New("expected a CREATE VIEW statement")
)

type ImpossibleApplyDiffOrderError struct {
	UnorderedDiffs   []EntityDiff
	ConflictingDiffs []EntityDiff
}

func (e *ImpossibleApplyDiffOrderError) Error() string {
	var b strings.Builder
	conflictingStatements := e.ConflictingStatements()
	fmt.Fprintf(&b, "no valid applicable order for diffs. %d diffs found conflicting:", len(conflictingStatements))
	for _, s := range conflictingStatements {
		b.WriteString("\n")
		b.WriteString(s)

View on GitHub (pinned to 01a25a7d17)

Solutions

1. Compare indexes without strict ordering (use the default diff behavior)
2. Normalize index order in both schemas before diffing
3. Apply the generated diff instead of expecting identical DDL text

if !indexOrdersMatch(a, b) { return fmt.Errorf("strict index ordering required but differs: %w", schemadiff.ErrStrictIndexOrderingUnsupported) }

if err != nil {
	if errors.Is(err, schemadiff.ErrStrictIndexOrderingUnsupported) {
		// fall back to non-strict diff
	}
}

When it happens

Trigger: Requesting a diff mode that demands strict index ordering between two CREATE TABLE entities whose indexes have the same content but different declaration order.

Common situations: Comparing schemas where ALTERs over time reordered index definitions; teams expecting byte-exact DDL output for equal-but-reordered indexes.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

• mismatched entity type
• unexpected diff action
• unexpected table spec
• expected a CREATE TABLE statement
• expected a CREATE VIEW statement

AI-assisted analysis of vitessio/vitess@01a25a7d17 (2026-09-01). Data as JSON: /api/errors/5507d55f975998f3. Report an issue: GitHub.