Method dryRunQuery

backend/plugin/db/bigquery/bigquery.go:220–301

dryRunQuery performs a dry run validation of the query without executing it. Returns validation status and estimated bytes to be processed.

(ctx context.Context, statement string, queryContext db.QueryContext)

// dryRunQuery performs a dry run validation of the query without executing it.
// Returns validation status and estimated bytes to be processed.
func (d *Driver) dryRunQuery(ctx context.Context, statement string, queryContext db.QueryContext) ([]*v1pb.QueryResult, error) {
	statements, err := util.SanitizeSQL(statement)
	if err != nil {
		return nil, err
	}

	var results []*v1pb.QueryResult
	for _, stmt := range statements {
		startTime := time.Now()

		q := d.client.Query(stmt)
		q.DefaultDatasetID = d.databaseName
		q.DryRun = true

		if queryContext.OperatorEmail != "" {
			q.Labels = map[string]string{"operator_email": encodeOperatorEmail(queryContext.OperatorEmail)}
		}

		job, err := q.Run(ctx)
		if err != nil {
			results = append(results, &v1pb.QueryResult{
				Statement: stmt,
				Error:     err.Error(),
				Latency:   durationpb.New(time.Since(startTime)),
			})
			continue
		}

		// For dry run, the job completes immediately - use Status() instead of Wait()
		status := job.LastStatus()
		if status == nil {
			results = append(results, &v1pb.QueryResult{
				Statement: stmt,
				Error:     "failed to get job status",
				Latency:   durationpb.New(time.Since(startTime)),
			})
			continue
		}

		if err := status.Err(); err != nil {
			results = append(results, &v1pb.QueryResult{
				Statement: stmt,
				Error:     err.Error(),
				Latency:   durationpb.New(time.Since(startTime)),
			})
			continue
		}

		// Extract dry run results
		result := &v1pb.QueryResult{
			Statement: stmt,
			Latency:   durationpb.New(time.Since(startTime)),
		}

		if stats, ok := status.Statistics.Details.(*bigquery.QueryStatistics); ok {
			bytesProcessed := stats.TotalBytesProcessed

			// Format output similar to bq CLI