diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c index 786ee865f147..be3629cd57a5 100644 --- a/src/backend/commands/explain.c +++ b/src/backend/commands/explain.c @@ -3628,6 +3628,26 @@ show_memoize_info(MemoizeState *mstate, List *ancestors, ExplainState *es) ExplainPropertyText("Cache Key", keystr.data, es); ExplainPropertyText("Cache Mode", mstate->binary_mode ? "binary" : "logical", es); + if (es->costs) + { + if (es->format == EXPLAIN_FORMAT_TEXT) + { + ExplainIndentText(es); + appendStringInfo(es->str, "Estimates: capacity=%u distinct keys=%.0f lookups=%.0f hit ratio=%.2f%%\n", + ((Memoize *) plan)->est_entries, + ((Memoize *) plan)->est_unique_keys, + ((Memoize *) plan)->lookups, + ((Memoize *) plan)->hit_ratio * 100.0); + } + else + { + ExplainPropertyUInteger("Estimated Capacity", "", ((Memoize *) plan)->est_entries, es); + ExplainPropertyFloat("Estimated Distinct Lookup Keys", "", ((Memoize *) plan)->est_unique_keys, 0, es); + ExplainPropertyFloat("Estimated Lookups", "", ((Memoize *) plan)->lookups, 0, es); + ExplainPropertyFloat("Estimated Hit Ratio", "", ((Memoize *) plan)->hit_ratio * 100.0, 2, es); + } + } + pfree(keystr.data); if (!es->analyze) diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c index 60b0fcfb6be5..3e99214501b4 100644 --- a/src/backend/optimizer/path/costsize.c +++ b/src/backend/optimizer/path/costsize.c @@ -2604,6 +2604,9 @@ cost_memoize_rescan(PlannerInfo *root, MemoizePath *mpath, mpath->est_entries = Min(Min(ndistinct, est_cache_entries), PG_UINT32_MAX); + /* Remember ndistinct for a potential EXPLAIN later */ + mpath->est_unique_keys = ndistinct; + /* * When the number of distinct parameter values is above the amount we can * store in the cache, then we'll have to evict some entries from the @@ -2621,6 +2624,9 @@ cost_memoize_rescan(PlannerInfo *root, MemoizePath *mpath, hit_ratio = ((calls - ndistinct) / calls) * (est_cache_entries / Max(ndistinct, est_cache_entries)); + /* Remember cache hit ratio for a potential EXPLAIN later */ + mpath->hit_ratio = hit_ratio; + Assert(hit_ratio >= 0 && hit_ratio <= 1.0); /* diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c index a8f22a8c154a..47a092747d5f 100644 --- a/src/backend/optimizer/plan/createplan.c +++ b/src/backend/optimizer/plan/createplan.c @@ -284,7 +284,9 @@ static Material *make_material(Plan *lefttree); static Memoize *make_memoize(Plan *lefttree, Oid *hashoperators, Oid *collations, List *param_exprs, bool singlerow, bool binary_mode, - uint32 est_entries, Bitmapset *keyparamids); + uint32 est_entries, Bitmapset *keyparamids, + double est_unique_keys, double hit_ratio, + double lookups); static WindowAgg *make_windowagg(List *tlist, WindowClause *wc, int partNumCols, AttrNumber *partColIdx, Oid *partOperators, Oid *partCollations, int ordNumCols, AttrNumber *ordColIdx, Oid *ordOperators, Oid *ordCollations, @@ -1703,7 +1705,9 @@ create_memoize_plan(PlannerInfo *root, MemoizePath *best_path, int flags) plan = make_memoize(subplan, operators, collations, param_exprs, best_path->singlerow, best_path->binary_mode, - best_path->est_entries, keyparamids); + best_path->est_entries, keyparamids, + best_path->est_unique_keys, best_path->hit_ratio, + best_path->calls); copy_generic_path_info(&plan->plan, (Path *) best_path); @@ -6636,7 +6640,9 @@ materialize_finished_plan(Plan *subplan) static Memoize * make_memoize(Plan *lefttree, Oid *hashoperators, Oid *collations, List *param_exprs, bool singlerow, bool binary_mode, - uint32 est_entries, Bitmapset *keyparamids) + uint32 est_entries, Bitmapset *keyparamids, + double est_unique_keys, double hit_ratio, + double lookups) { Memoize *node = makeNode(Memoize); Plan *plan = &node->plan; @@ -6654,6 +6660,9 @@ make_memoize(Plan *lefttree, Oid *hashoperators, Oid *collations, node->binary_mode = binary_mode; node->est_entries = est_entries; node->keyparamids = keyparamids; + node->est_unique_keys = est_unique_keys; + node->hit_ratio = hit_ratio; + node->lookups = lookups; return node; } diff --git a/src/backend/optimizer/util/pathnode.c b/src/backend/optimizer/util/pathnode.c index 93e73cb44dbb..40674027f9ff 100644 --- a/src/backend/optimizer/util/pathnode.c +++ b/src/backend/optimizer/util/pathnode.c @@ -1701,6 +1701,18 @@ create_memoize_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, Assert(enable_memoize); pathnode->path.disabled_nodes = subpath->disabled_nodes; + /* + * Estimated number of distinct memoization keys, + * computed using estimate_num_groups() + */ + pathnode->est_unique_keys = 0; + + /* + * The estimated cache hit ratio will calculated later + * by cost_memoize_rescan(). + */ + pathnode->hit_ratio = 0; + /* * Add a small additional charge for caching the first entry. All the * harder calculations for rescans are performed in cost_memoize_rescan(). diff --git a/src/include/nodes/pathnodes.h b/src/include/nodes/pathnodes.h index 011e5a811c3f..ba4097a4b907 100644 --- a/src/include/nodes/pathnodes.h +++ b/src/include/nodes/pathnodes.h @@ -2138,6 +2138,9 @@ typedef struct MemoizePath uint32 est_entries; /* The maximum number of entries that the * planner expects will fit in the cache, or 0 * if unknown */ + double est_unique_keys; /* Estimated number of distinct memoization keys, + * used for cache size evaluation. Kept for EXPLAIN */ + double hit_ratio; /* Estimated cache hit ratio. Kept for EXPLAIN */ } MemoizePath; /* diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h index 658d76225e47..6eb08866304c 100644 --- a/src/include/nodes/plannodes.h +++ b/src/include/nodes/plannodes.h @@ -1063,6 +1063,18 @@ typedef struct Memoize /* paramids from param_exprs */ Bitmapset *keyparamids; + + /* + * Estimated number of distinct memoization keys, + * used for cache size evaluation. Kept for EXPLAIN + */ + double est_unique_keys; + + /* Estimated cache hit ratio. Kept for EXPLAIN */ + double hit_ratio; + + /* Estimated number of lookups. Kept for EXPLAIN */ + double lookups; } Memoize; /* ----------------