Method delete

internal/storage/postgres/data_writer.go:242–314

delete handles the deletion of tuples and attributes from the database based on provided filters. It returns an EncodedSnapToken upon successful deletion or an error if the deletion fails.

(
	ctx context.Context,
	tenantID string,
	tupleFilter *base.TupleFilter,
	attributeFilter *base.AttributeFilter,
)

// delete handles the deletion of tuples and attributes from the database based on provided filters.
// It returns an EncodedSnapToken upon successful deletion or an error if the deletion fails.
func (w *DataWriter) delete(
	ctx context.Context,
	tenantID string,
	tupleFilter *base.TupleFilter,
	attributeFilter *base.AttributeFilter,
) (token token.EncodedSnapToken, err error) {
	var tx pgx.Tx
	tx, err = w.database.WritePool.BeginTx(ctx, w.txOptions)
	if err != nil {
		return nil, err
	}
	// Defer rollback
	defer func() {
		_ = tx.Rollback(ctx)
	}()
	// Get transaction ID and snapshot
	var xid db.XID8
	var snapshotValue string
	err = tx.QueryRow(ctx, utils.TransactionTemplate, tenantID).Scan(&xid, &snapshotValue)
	if err != nil {
		return nil, err
	}

	slog.DebugContext(ctx, "retrieved transaction", slog.Any("xid", xid), "for tenant", slog.Any("tenant_id", tenantID))

	slog.DebugContext(ctx, "processing tuple and executing update query")
	// Process tuple filter
	if !validation.IsTupleFilterEmpty(tupleFilter) {
		tbuilder := w.database.Builder.Update(RelationTuplesTable).Set("expired_tx_id", xid).Where(squirrel.Eq{"expired_tx_id": utils.ActiveRecordTxnID, "tenant_id": tenantID})
		tbuilder = utils.TuplesFilterQueryForUpdateBuilder(tbuilder, tupleFilter)

		var tquery string
		var targs []interface{}

		tquery, targs, err = tbuilder.ToSql()
		if err != nil {
			return nil, err
		}

		_, err = tx.Exec(ctx, tquery, targs...)
		if err != nil {
			return nil, err
		}
	}

	slog.DebugContext(ctx, "processing attribute and executing update query")
	// Process attribute filter
	if !validation.IsAttributeFilterEmpty(attributeFilter) {
		abuilder := w.database.Builder.Update(AttributesTable).Set("expired_tx_id", xid).Where(squirrel.Eq{"expired_tx_id": utils.ActiveRecordTxnID, "tenant_id": tenantID})
		abuilder = utils.AttributesFilterQueryForUpdateBuilder(abuilder, attributeFilter)
		// Declare query variables
		var aquery string
		var aargs []interface{}
		// Generate SQL query
		aquery, aargs, err = abuilder.ToSql()
		if err != nil {
			return nil, err
		}