Fix collecting eclasses routine.

Author: Daniil Anisimov

aqo.c

@@ -118,6 +118,7 @@ aqo_free_callback(ResourceReleasePhase phase,
 	{
 		MemoryContextReset(AQOCacheMemCtx);
 		cur_classes = NIL;
+		aqo_eclass_collector = NIL;
 	}
 }
 

hash.c

@@ -641,18 +641,28 @@ get_clauselist_args(List *clauselist, int *nargs, int **args_hash)
 	*args_hash = repalloc(*args_hash, (*nargs) * sizeof(**args_hash));
 	p_sorted = repalloc(p_sorted, (*nargs) * sizeof(*p_sorted));
 
-	/* Compress the values of eclasses */
+	/*
+	 * Compress the values of eclasses.
+	 * It is only sorted in order of args_hash.
+	 * Get the indexes in ascending order of the elements.
+	 */
+	idx = argsort(p_sorted, *nargs, sizeof(*p_sorted), int_cmp);
+
+	/*
+	 * Remove the holes from given array.
+	 * Later we can use it as indexes of args_hash.
+	 */
 	if (*nargs > 0)
 	{
-		int prev = p_sorted[0];
-		p_sorted[0] = 0;
+		int prev = p_sorted[idx[0]];
+		p_sorted[idx[0]] = 0;
 		for (i = 1; i < *nargs; i++)
 		{
-			int cur = p_sorted[i];
+			int cur = p_sorted[idx[i]];
 			if (cur == prev)
-				p_sorted[i] = p_sorted[i-1];
+				p_sorted[idx[i]] = p_sorted[idx[i-1]];
 			else
-				p_sorted[i] = p_sorted[i-1] + 1;
+				p_sorted[idx[i]] = p_sorted[idx[i-1]] + 1;
 			prev = cur;
 		}
 	}

path_utils.c

@@ -52,13 +52,13 @@ static AQOPlanNode DefaultAQOPlanNode =
 	.prediction = -1.
 };
 
-
 /*
  * Auxiliary list for relabel equivalence classes
  * from pointers to the serial numbers - indexes of this list.
- * Maybe it's need to use some smart data structure such a HTAB?
+ * XXX: Maybe it's need to use some smart data structure such a HTAB?
+ * It must be allocated in AQOCacheMemCtx.
  */
-List *eclass_collector = NIL;
+List *aqo_eclass_collector = NIL;
 
 /*
  * Hook on creation of a plan node. We need to store AQO-specific data to
@@ -345,13 +345,6 @@ aqo_get_raw_clauses(PlannerInfo *root, List *restrictlist)
 	return clauses;
 }
 
-void
-eclass_collector_free(void)
-{
-	list_free(eclass_collector);
-	eclass_collector = NIL;
-}
-
 static int
 get_eclass_index(EquivalenceClass *ec)
 {
@@ -366,16 +359,16 @@ get_eclass_index(EquivalenceClass *ec)
 	while(ec->ec_merged)
 		ec = ec->ec_merged;
 
-	foreach (lc, eclass_collector)
+	foreach (lc, aqo_eclass_collector)
 	{
 		if (lfirst(lc) == ec)
 			break;
 		i++;
 	}
 
 	old_ctx = MemoryContextSwitchTo(AQOCacheMemCtx);
-	if (i == list_length(eclass_collector))
-		eclass_collector = lappend(eclass_collector, ec);
+	if (i == list_length(aqo_eclass_collector))
+		aqo_eclass_collector = lappend(aqo_eclass_collector, ec);
 	MemoryContextSwitchTo(old_ctx);
 
 	return i;

path_utils.h

@@ -8,6 +8,8 @@
 #define AQO_PLAN_NODE	"AQOPlanNode"
 #define AQO_CONST_NODE	"AQOConstNode"
 
+extern List *aqo_eclass_collector;
+
 /*
  * Find and sort out relations that used in the query:
  * Use oids of relations to store dependency of ML row on a set of tables.
@@ -114,6 +116,5 @@ extern void RegisterAQOPlanNodeMethods(void);
 extern List *aqo_get_clauses(PlannerInfo *root, List *restrictlist);
 
 void aqo_path_utils_init(void);
-void eclass_collector_free(void);
 
 #endif /* PATH_UTILS_H */

postprocessing.c

@@ -848,7 +848,6 @@ aqo_ExecutorEnd(QueryDesc *queryDesc)
 end:
 	/* Release all AQO-specific memory, allocated during learning procedure */
 	selectivity_cache_clear();
-	eclass_collector_free();
 	MemoryContextSwitchTo(oldctx);
 	MemoryContextReset(AQOLearnMemCtx);