Fix the two stupid bugs. Intro AQO memory context for long-live data.

Author: danolivo

aqo.c

@@ -50,6 +50,12 @@ bool		explain_aqo;
 instr_time	query_starttime;
 double		query_planning_time;
 
+/*
+ * Currently we use it only to store query_text string which is initialized
+ * after a query parsing and is used during the query planning.
+ */
+MemoryContext AQOMemoryContext;
+
 /* Saved hook values */
 post_parse_analyze_hook_type				prev_post_parse_analyze_hook;
 planner_hook_type							prev_planner_hook;
@@ -105,6 +111,8 @@ _PG_init(void)
 	ExplainOnePlan_hook							= print_into_explain;
 
 	init_deactivated_queries_storage();
+
+	AQOMemoryContext = AllocSetContextCreate(TopMemoryContext, "AQOMemoryContext", ALLOCSET_DEFAULT_SIZES);
 }
 
 PG_FUNCTION_INFO_V1(invalidate_deactivated_queries_cache);

aqo.h

@@ -142,6 +142,7 @@
 #include "utils/builtins.h"
 #include "utils/guc.h"
 #include "utils/hsearch.h"
+#include "utils/memutils.h"
 #include "utils/rel.h"
 #include "utils/tqual.h"
 #include "utils/fmgroids.h"
@@ -217,6 +218,9 @@ extern bool explain_aqo;
 extern instr_time query_starttime;
 extern double query_planning_time;
 
+/* Memory context for long-live data */
+extern MemoryContext AQOMemoryContext;
+
 /* Saved hook values in case of unload */
 extern post_parse_analyze_hook_type prev_post_parse_analyze_hook;
 extern planner_hook_type prev_planner_hook;

auto_tuning.c

@@ -106,7 +106,7 @@ is_in_infinite_loop_cq(double *elems, int nelems)
  * we cannot execute queries on our own wish, so the tuning now is in setting
  * use_aqo and learn_aqo parameters for the query type.
  *
- * Now the workflow is quite simlple:
+ * Now the workflow is quite simple:
  *
  * Firstly, we run a new query type auto_tuning_window_size times without our
  * method to have an execution time statistics for such type of queries.

machine_learning.c

@@ -116,14 +116,14 @@ OkNNr_predict(int matrix_rows, int matrix_cols,
 		if (idx[i] != -1)
 			result += targets[idx[i]] * w[i] / w_sum;
 
-	pfree(distances);
-	pfree(idx);
-	pfree(w);
-
 	/* this should never happen */
 	if (idx[0] == -1)
 		return -1;
 
+	pfree(distances);
+	pfree(idx);
+	pfree(w);
+
 	if (result < 0)
 		result = 0;
 	return result;

preprocessing.c

@@ -67,8 +67,16 @@ static bool isQueryUsingSystemRelation_walker(Node *node, void *context);
 void
 get_query_text(ParseState *pstate, Query *query)
 {
+	MemoryContext	oldCxt;
+
+	/*
+	 * Duplicate query string into private AQO memory context for guard
+	 * from possible memory context switching.
+	 */
+	oldCxt = MemoryContextSwitchTo(AQOMemoryContext);
 	if (pstate)
-		Assert((query_text = strdup(pstate->p_sourcetext)) != NULL);
+		query_text = pstrdup(pstate->p_sourcetext);
+	MemoryContextSwitchTo(oldCxt);
 
 	if (prev_post_parse_analyze_hook)
 		prev_post_parse_analyze_hook(pstate, query);