t8y2/dbx · error

failed to parse constraint %s columns: %w

Error message

failed to parse constraint %s columns: %w

What it means

While reading table constraints from the catalog, the driver parses the constraint's own column list (stored as attribute-number text like '1 2 3') via parseVastbaseConstraintAttributeNumbers. If that parse fails (non-numeric token after splitting on commas/spaces/tabs), the error is wrapped as 'failed to parse constraint %s columns'.

Source

Thrown at agents/drivers/vastbase-go/vastbase_metadata.go:1585

	type rawConstraint struct {
		name, kind, definition                        string
		columnNumbers, refColumnNumbers               []int
		refSchema, refTable                           sql.NullString
		matchType, onUpdate, onDelete                 sql.NullString
		deferrable, initiallyDeferred, valid, enabled bool
	}
	raw := []rawConstraint{}
	for rows.Next() {
		var item rawConstraint
		var columnsRaw, refColumnsRaw sql.NullString
		var validRaw, enabledRaw any
		if err := rows.Scan(&item.name, &item.kind, &item.definition, &columnsRaw, &item.refSchema, &item.refTable, &refColumnsRaw, &item.matchType, &item.onUpdate, &item.onDelete, &item.deferrable, &item.initiallyDeferred, &validRaw, &enabledRaw); err != nil {
			return nil, err
		}
		item.columnNumbers, err = parseVastbaseConstraintAttributeNumbers(columnsRaw.String)
		if err != nil {
			return nil, fmt.Errorf("failed to parse constraint %s columns: %w", item.name, err)
		}
		item.refColumnNumbers, err = parseVastbaseConstraintAttributeNumbers(refColumnsRaw.String)
		if err != nil {
			return nil, fmt.Errorf("failed to parse constraint %s referenced columns: %w", item.name, err)
		}
		item.valid = parseVastbaseConstraintValid(validRaw)
		item.enabled = parseVastbaseConstraintEnabled(enabledRaw)
		raw = append(raw, item)
	}
	if err := rows.Err(); err != nil {
		return nil, err
	}

	attributes, err := s.relationAttributesByNumber(catalog, prefix, effective, table)
	if err != nil {
		return nil, err
	}
	refAttributes := map[string]map[int]string{}

View on GitHub (pinned to c0390bff16)

Solutions

1. Inspect the constraint named in the error and its catalog conkey value; check for empty/malformed data.
2. Confirm the server version is supported by the driver; upgrade the driver if catalog formats changed.
3. If the value is legitimately empty (e.g. NOT NULL constraints have no conkey), the driver may need updating to skip empty values.
4. Query the constraint directly (SELECT conkey FROM pg_constraint WHERE conname=...) to diagnose the raw value.

// sanity-check conkey text before/during introspection
var conkey string
err := db.QueryRow(`SELECT conkey::text FROM pg_constraint WHERE conname=$1`, cname).Scan(&conkey)
if err == nil {
    for _, tok := range strings.FieldsFunc(conkey, func(r rune) bool { return r == ',' || r == ' ' || r == '\t' }) {
        if _, e := strconv.Atoi(tok); e != nil {
            return fmt.Errorf("malformed conkey %q for constraint %s", conkey, cname)
        }
    }
}

cols, err := srv.ListConstraints(schema, table)
if err != nil && strings.Contains(err.Error(), "failed to parse constraint") {
    // log constraint name from error and inspect its catalog row
    return fmt.Errorf("introspection blocked by malformed constraint data: %w", err)
}

When it happens

Trigger: Introspecting constraints when a constraint row's conkey column contains an unexpected format — e.g. empty string, NULL rendered oddly, or a value with characters other than digits, commas, spaces, or tabs.

Common situations: Non-standard Vastbase/PG-compatible server whose catalog text representation differs; corrupted or unusual catalog rows; driver version mismatch with server catalog format.

Understand the failure class

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• failed to parse constraint %s referenced columns: %w
• invalid attribute number %q
• %s.%s is the auto-generated row type of a relation, not an i
• failed to read enum values: %w
• failed to read composite fields: %w

AI-assisted analysis of t8y2/dbx@c0390bff16 (2026-09-05). Data as JSON: /api/errors/72a151d2579bf1ac. Report an issue: GitHub.