Remove some unused and seldom used fields from RelationAmInfo.

This saves some memory from each index relcache entry. At least on a 64-bit
machine, it saves just enough to shrink a typical relcache entry's memory
usage from 2k to 1k. That's nice if you have a lot of backends and a lot of
indexes.

diff --git a/src/backend/access/index/indexam.c b/src/backend/access/index/indexam.c
index ce94649281d93a69e2d733f78b75166cdbdcb969..b87815544d9eec6131447c718ccd8648eae1b90f 100644 (file)
--- a/src/backend/access/index/indexam.c
+++ b/src/backend/access/index/indexam.c
@@ -114,6 +114,13 @@ do { \
    } \
 } while(0)
 
+#define GET_UNCACHED_REL_PROCEDURE(pname) \
+do { \
+   if (!RegProcedureIsValid(indexRelation->rd_am->pname)) \
+       elog(ERROR, "invalid %s regproc", CppAsString(pname)); \
+   fmgr_info(indexRelation->rd_am->pname, &procedure); \
+} while(0)
+
 #define GET_SCAN_PROCEDURE(pname) \
 do { \
    procedure = &scan->indexRelation->rd_aminfo->pname; \
@@ -671,14 +678,14 @@ index_bulk_delete(IndexVacuumInfo *info,
                  void *callback_state)
 {
    Relation    indexRelation = info->index;
-   FmgrInfo   *procedure;
+   FmgrInfo    procedure;
    IndexBulkDeleteResult *result;
 
    RELATION_CHECKS;
-   GET_REL_PROCEDURE(ambulkdelete);
+   GET_UNCACHED_REL_PROCEDURE(ambulkdelete);
 
    result = (IndexBulkDeleteResult *)
-       DatumGetPointer(FunctionCall4(procedure,
+       DatumGetPointer(FunctionCall4(&procedure,
                                      PointerGetDatum(info),
                                      PointerGetDatum(stats),
                                      PointerGetDatum((Pointer) callback),
@@ -698,14 +705,14 @@ index_vacuum_cleanup(IndexVacuumInfo *info,
                     IndexBulkDeleteResult *stats)
 {
    Relation    indexRelation = info->index;
-   FmgrInfo   *procedure;
+   FmgrInfo    procedure;
    IndexBulkDeleteResult *result;
 
    RELATION_CHECKS;
-   GET_REL_PROCEDURE(amvacuumcleanup);
+   GET_UNCACHED_REL_PROCEDURE(amvacuumcleanup);
 
    result = (IndexBulkDeleteResult *)
-       DatumGetPointer(FunctionCall2(procedure,
+       DatumGetPointer(FunctionCall2(&procedure,
                                      PointerGetDatum(info),
                                      PointerGetDatum(stats)));
 

diff --git a/src/include/utils/rel.h b/src/include/utils/rel.h
index 1fd3f67b1e4861dff57c94ef4d7a0707cecb8612..632743af9436e14f8b537e58d2fc0acbbb319873 100644 (file)
--- a/src/include/utils/rel.h
+++ b/src/include/utils/rel.h
@@ -47,8 +47,8 @@ typedef LockInfoData *LockInfo;
 
 
 /*
- * Cached lookup information for the index access method functions defined
- * by the pg_am row associated with an index relation.
+ * Cached lookup information for the frequently used index access method
+ * functions, defined by the pg_am row associated with an index relation.
  */
 typedef struct RelationAmInfo
 {
@@ -60,13 +60,7 @@ typedef struct RelationAmInfo
    FmgrInfo    amendscan;
    FmgrInfo    ammarkpos;
    FmgrInfo    amrestrpos;
-   FmgrInfo    ambuild;
-   FmgrInfo    ambuildempty;
-   FmgrInfo    ambulkdelete;
-   FmgrInfo    amvacuumcleanup;
    FmgrInfo    amcanreturn;
-   FmgrInfo    amcostestimate;
-   FmgrInfo    amoptions;
 } RelationAmInfo;