fix row copy

flow/connectors/bigquery/bigquery.go

@@ -7,6 +7,7 @@ import (
 	"log/slog"
 	"reflect"
 	"regexp"
+	"slices"
 	"strings"
 	"time"
 
@@ -460,20 +461,26 @@ func (c *BigQueryConnector) getTableNametoUnchangedCols(flowJobName string, sync
 	// Create a map to store the results.
 	resultMap := make(map[string][]string)
 
-	// Process the query results using an iterator.
-	var row struct {
-		Tablename             string   `bigquery:"_peerdb_destination_table_name"`
-		UnchangedToastColumns []string `bigquery:"unchanged_toast_columns"`
-	}
 	for {
+		// Process the query results using an iterator.
+		var row struct {
+			Tablename             string   `bigquery:"_peerdb_destination_table_name"`
+			UnchangedToastColumns []string `bigquery:"unchanged_toast_columns"`
+		}
+
 		err := it.Next(&row)
 		if err == iterator.Done {
 			break
 		}
 		if err != nil {
 			return nil, err
 		}
-		resultMap[row.Tablename] = row.UnchangedToastColumns
+
+		resultMap[row.Tablename] = slices.Clone(row.UnchangedToastColumns)
+		c.logger.Info("unchanged toast columns",
+			slog.String("table", row.Tablename),
+			slog.Any("columns", row.UnchangedToastColumns),
+		)
 	}
 	return resultMap, nil
 }