just fetch childToParentRelIDMapping for tables we want

flow/connectors/postgres/cdc.go

@@ -85,16 +85,18 @@ func (c *PostgresConnector) NewPostgresCDCSource(cdcConfig *PostgresCDCConfig) *
 	}
 }
 
-func GetChildToParentRelIDMap(ctx context.Context, conn *pgx.Conn) (map[uint32]uint32, error) {
+func GetChildToParentRelIDMap(ctx context.Context,
+	conn *pgx.Conn, parentTableOIDs []uint32,
+) (map[uint32]uint32, error) {
 	query := `
 		SELECT parent.oid AS parentrelid, child.oid AS childrelid
 		FROM pg_inherits
 		JOIN pg_class parent ON pg_inherits.inhparent = parent.oid
 		JOIN pg_class child ON pg_inherits.inhrelid = child.oid
-		WHERE parent.relkind IN ('p','r');
+		WHERE parent.relkind IN ('p','r') AND parent.oid=ANY($1);
 	`
 
-	rows, err := conn.Query(ctx, query)
+	rows, err := conn.Query(ctx, query, parentTableOIDs)
 	if err != nil {
 		return nil, fmt.Errorf("error querying for child to parent relid map: %w", err)
 	}

flow/connectors/postgres/postgres.go

@@ -5,6 +5,8 @@ import (
 	"errors"
 	"fmt"
 	"log/slog"
+	"maps"
+	"slices"
 	"strings"
 	"sync"
 	"sync/atomic"
@@ -398,7 +400,7 @@ func pullCore[Items model.Items](
 	var childToParentRelIDMap map[uint32]uint32
 	// only initialize the map if needed, escape hatch because custom publications may not have the right setting
 	if req.OverridePublicationName != "" || pgVersion < shared.POSTGRES_13 {
-		childToParentRelIDMap, err = GetChildToParentRelIDMap(ctx, c.conn)
+		childToParentRelIDMap, err = GetChildToParentRelIDMap(ctx, c.conn, slices.Collect(maps.Keys(req.SrcTableIDNameMapping)))
 		if err != nil {
 			return fmt.Errorf("error getting child to parent relid map: %w", err)
 		}