Remove EState.es_range_table_array.

Now that list_nth is O(1), there's no good reason to maintain a
separate array of RTE pointers rather than indexing into
estate->es_range_table.  Deleting the array doesn't save all that
much either; but just on cleanliness grounds, it's better not to
have duplicate representations of the identical information.

Discussion: https://postgr.es/m/14960.1565384592@sss.pgh.pa.us

diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index dbd7dd9bcd4ece8513024b14201c5963dd8006be..7f494abf14ab632908134ff950b5f7572dafc4de 100644 (file)
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -2790,7 +2790,6 @@ EvalPlanQualStart(EPQState *epqstate, EState *parentestate, Plan *planTree)
        estate->es_snapshot = parentestate->es_snapshot;
        estate->es_crosscheck_snapshot = parentestate->es_crosscheck_snapshot;
        estate->es_range_table = parentestate->es_range_table;
-       estate->es_range_table_array = parentestate->es_range_table_array;
        estate->es_range_table_size = parentestate->es_range_table_size;
        estate->es_relations = parentestate->es_relations;
        estate->es_queryEnv = parentestate->es_queryEnv;

diff --git a/src/backend/executor/execUtils.c b/src/backend/executor/execUtils.c
index c1fc0d54e956a0555f75108aa90af638d452ceb2..afd9bebdbdc93612d212cb7e9880cf0dcd450f14 100644 (file)
--- a/src/backend/executor/execUtils.c
+++ b/src/backend/executor/execUtils.c
@@ -113,7 +113,6 @@ CreateExecutorState(void)
        estate->es_snapshot = InvalidSnapshot;  /* caller must initialize this */
        estate->es_crosscheck_snapshot = InvalidSnapshot;       /* no crosscheck */
        estate->es_range_table = NIL;
-       estate->es_range_table_array = NULL;
        estate->es_range_table_size = 0;
        estate->es_relations = NULL;
        estate->es_rowmarks = NULL;
@@ -720,29 +719,17 @@ ExecOpenScanRelation(EState *estate, Index scanrelid, int eflags)
  * ExecInitRangeTable
  *             Set up executor's range-table-related data
  *
- * We build an array from the range table list to allow faster lookup by RTI.
- * (The es_range_table field is now somewhat redundant, but we keep it to
- * avoid breaking external code unnecessarily.)
- * This is also a convenient place to set up the parallel es_relations array.
+ * In addition to the range table proper, initialize arrays that are
+ * indexed by rangetable index.
  */
 void
 ExecInitRangeTable(EState *estate, List *rangeTable)
 {
-       Index           rti;
-       ListCell   *lc;
-
        /* Remember the range table List as-is */
        estate->es_range_table = rangeTable;
 
-       /* Set up the equivalent array representation */
+       /* Set size of associated arrays */
        estate->es_range_table_size = list_length(rangeTable);
-       estate->es_range_table_array = (RangeTblEntry **)
-               palloc(estate->es_range_table_size * sizeof(RangeTblEntry *));
-       rti = 0;
-       foreach(lc, rangeTable)
-       {
-               estate->es_range_table_array[rti++] = lfirst_node(RangeTblEntry, lc);
-       }
 
        /*
         * Allocate an array to store an open Relation corresponding to each
@@ -753,8 +740,8 @@ ExecInitRangeTable(EState *estate, List *rangeTable)
                palloc0(estate->es_range_table_size * sizeof(Relation));
 
        /*
-        * es_rowmarks is also parallel to the es_range_table_array, but it's
-        * allocated only if needed.
+        * es_rowmarks is also parallel to the es_range_table, but it's allocated
+        * only if needed.
         */
        estate->es_rowmarks = NULL;
 }

diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
index 1fb28b4596be0f655d303c8b238a3afeb216536f..39c8b3bbbe8d8d2f4a6b4bad47607055c8c9d0e8 100644 (file)
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -535,8 +535,7 @@ extern void ExecInitRangeTable(EState *estate, List *rangeTable);
 static inline RangeTblEntry *
 exec_rt_fetch(Index rti, EState *estate)
 {
-       Assert(rti > 0 && rti <= estate->es_range_table_size);
-       return estate->es_range_table_array[rti - 1];
+       return (RangeTblEntry *) list_nth(estate->es_range_table, rti - 1);
 }
 
 extern Relation ExecGetRangeTableRelation(EState *estate, Index rti);

diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 4ec78491f6f75aea875122ae99706270d5b999d3..063b49013c66dac8b6bf512820b30471a46037b1 100644 (file)
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -502,7 +502,6 @@ typedef struct EState
        Snapshot        es_snapshot;    /* time qual to use */
        Snapshot        es_crosscheck_snapshot; /* crosscheck time qual for RI */
        List       *es_range_table; /* List of RangeTblEntry */
-       struct RangeTblEntry **es_range_table_array;    /* equivalent array */
        Index           es_range_table_size;    /* size of the range table arrays */
        Relation   *es_relations;       /* Array of per-range-table-entry Relation
                                                                 * pointers, or NULL if not yet opened */