cannot build a row streamer plan for the %s table as a lastp

Error message

cannot build a row streamer plan for the %s table as a lastpk value was provided (%v) and the number of primary key values within it (%d) does not match the number of primary key columns in the table (%d)

What it means

When resuming a copy phase, the saved lastpk must have exactly one value per primary key column of the table. buildSelect rejects the plan when the counts differ, because the WHERE clause (col1 = ? and col2 > ?) or (col1 > ?) cannot be constructed correctly.

Source

Thrown at go/vt/vttablet/tabletserver/vstreamer/rowstreamer.go:293

	// If we know the index name that we should be using then tell MySQL
	// to use it if possible. This helps to ensure that we are able to
	// leverage the ordering from the index itself and avoid having to
	// do a FILESORT of all the results. This index should contain all
	// of the PK columns which are used in the ORDER BY clause below.
	var indexHint string
	// If we're pushing down any expressions, we need to let the optimizer
	// choose the best index to use.
	if st.PKIndexName != "" && len(rs.plan.whereExprsToPushDown) == 0 {
		escapedPKIndexName, err := sqlescape.EnsureEscaped(st.PKIndexName)
		if err != nil {
			return "", err
		}
		indexHint = fmt.Sprintf(" force index (%s)", escapedPKIndexName)
	}
	buf.Myprintf(" from %v%s", sqlparser.NewIdentifierCS(rs.plan.Table.Name), indexHint)
	if len(rs.lastpk) != 0 { // We're in the Nth copy phase cycle and need to resume
		if len(rs.lastpk) != len(rs.pkColumns) {
			return "", fmt.Errorf("cannot build a row streamer plan for the %s table as a lastpk value was provided (%v) and the number of primary key values within it (%d) does not match the number of primary key columns in the table (%d)",
				st.Name, rs.lastpk, len(rs.lastpk), len(rs.pkColumns))
		}
		buf.WriteString(" where ")
		// This closure handles the case for composite PKs. For example,
		// if lastpk was (1,2), the where clause would be:
		// (col1 = 1 and col2 > 2) or (col1 > 1).
		// A tuple inequality like (col1,col2) > (1,2) ends up
		// being a full table scan for MySQL.
		addLastPKExpressions := func() {
			prefix := ""
			for lastcol, pkCol := range slices.Backward(rs.pkColumns) {
				buf.Myprintf("%s(", prefix)
				prefix = " or "
				for i, pk := range rs.pkColumns[:lastcol] {
					buf.Myprintf("%v = ", sqlparser.NewIdentifierCI(rs.plan.Table.Fields[pk].Name))
					rs.lastpk[i].EncodeSQL(buf)
					buf.Myprintf(" and ")
				}

View on GitHub (pinned to 01a25a7d17)

Solutions

Check the table's current PK column count (SHOW INDEX/SHOW CREATE TABLE) and compare with the checkpointed lastpk in the workflow's vgtid.
If the PK changed, reset/restart the workflow's copy phase (or correct the TableLastPK) so lastpk is regenerated against the current schema.
Do not hand-edit checkpoints; use vtctld workflow restart/copy-phase reset so lastpk is rebuilt from live schema.

Defensive patterns

Strategy: validation

Validate before calling

pkCols := getPrimaryKeyColumns(tableName)
lastpk := checkpoint.TableLastPK[tableName].Lastpk
if lastpk != nil && len(lastpk.Rows) > 0 && len(lastpk.Rows[0]) != len(pkCols) {
    return fmt.Errorf("stale lastpk for %s: %d values vs %d pk cols; reset copy phase", tableName, len(lastpk.Rows[0]), len(pkCols))
}

Try / catch

err := stream(ctx, filter, tablePKs)
if err != nil && strings.Contains(err.Error(), "does not match the number of primary key columns") {
    // drop the stale checkpoint and restart the copy phase
    restartWorkflowCopyPhase(ctx, workflowID)
}

Prevention

Never hand-edit VReplication checkpoints (TableLastPK/vgtid)
Re-plan workflows after any ALTER TABLE touching the primary key
Validate lastpk shape against current schema before resuming streams
Use vtctld workflow reset instead of manual state surgery

When it happens

Trigger: Calling Stream/VStreamRows with a TableLastPK whose lastpk values count differs from the table's PK column count — e.g. lastpk saved against an older schema whose PK had a different number of columns.

Common situations: Workflow checkpoint (vgtid TableLastPK) written before an ALTER TABLE changed the primary key; copying lastpk state between tables with different PKs; manual editing of VReplication state.

Related errors

AI-assisted analysis of vitessio/vitess@01a25a7d17 (2026-09-01). Data as JSON: /api/errors/f9c3daedd4e0229a. Report an issue: GitHub.