diff --git a/pg_store_plans.c b/pg_store_plans.c
index a8f01ca..c5fda3f 100644
--- a/pg_store_plans.c
+++ b/pg_store_plans.c
@@ -409,7 +409,7 @@ _PG_init(void)
 	  "Sets the maximum number of plans tracked by pg_store_plans.",
 							NULL,
 							&store_size,
-							1000,
+							5000,
 							100,
 							INT_MAX,
 							PGC_POSTMASTER,
@@ -471,7 +471,7 @@ _PG_init(void)
 					"Minimum duration to record plan in milliseconds.",
 							NULL,
 							&min_duration,
-							0,
+							10,
 							0,
 							INT_MAX,
 							PGC_SUSET,
@@ -517,7 +517,7 @@ _PG_init(void)
 							 "Log timings.",
 							 NULL,
 							 &log_timing,
-							 true,
+							 false,
 							 PGC_SUSET,
 							 0,
 							 NULL,
@@ -738,6 +738,15 @@ pgsp_shmem_startup(void)
 		pgver != PGSP_PG_MAJOR_VERSION)
 		goto data_error;
 
+	/* check if num is out of range */
+	if (num < 0 || num > store_size)
+	{
+	    ereport(LOG,
+		    (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+		     errmsg("Invalid number of entries in file: %d", num)));
+	    goto data_error;
+	}
+
 	for (i = 0; i < num; i++)
 	{
 		pgspEntry	temp;
@@ -930,6 +939,10 @@ pgsp_shmem_shutdown(int code, Datum arg)
 	/* Unlink query-texts file; it's not needed while shutdown */
 	unlink(PGSP_TEXT_FILE);
 
+	if (pbuffer){
+		free(pbuffer);  // or free(pbuffer)
+		pbuffer = NULL;
+	}
 	return;
 
 error:
@@ -940,6 +953,10 @@ pgsp_shmem_shutdown(int code, Datum arg)
 	if (file)
 		FreeFile(file);
 	unlink(PGSP_DUMP_FILE ".tmp");
+	if (pbuffer){
+		free(pbuffer);  // or free(pbuffer)
+		pbuffer = NULL;
+	}
 }
 
 
@@ -1356,8 +1373,13 @@ pgsp_store(char *plan, queryid_t queryId,
 	e->counters.temp_blks_read += bufusage->temp_blks_read;
 	e->counters.temp_blks_written += bufusage->temp_blks_written;
 
+#if PG_VERSION_NUM >= 170000 /* compatible with version 17 */
+	e->counters.blk_read_time += INSTR_TIME_GET_MILLISEC(bufusage->local_blk_read_time);
+	e->counters.blk_write_time += INSTR_TIME_GET_MILLISEC(bufusage->local_blk_write_time);
+#else
 	e->counters.blk_read_time += INSTR_TIME_GET_MILLISEC(bufusage->blk_read_time);
 	e->counters.blk_write_time += INSTR_TIME_GET_MILLISEC(bufusage->blk_write_time);
+#endif
 
 #if PG_VERSION_NUM >= 150000
 	e->counters.temp_blk_read_time += INSTR_TIME_GET_MILLISEC(bufusage->temp_blk_read_time);
@@ -1579,6 +1601,9 @@ pg_store_plans_internal(FunctionCallInfo fcinfo,
 			else
 				pstr = SHMEM_PLAN_PTR(entry);
 
+			if (pstr == NULL)
+				continue;			/* Ignore any entries with bogus texts */
+
 			switch (plan_format)
 			{
 				case PLAN_FORMAT_TEXT:
@@ -1682,6 +1707,11 @@ pg_store_plans_internal(FunctionCallInfo fcinfo,
 
 	/* clean up and return the tuplestore */
 	tuplestore_donestoring(tupstore);
+
+	if (pbuffer){
+		free(pbuffer);  // or free(pbuffer)
+		pbuffer = NULL;
+	}
 }
 
 /* Number of output arguments (columns) for pg_stat_statements_info */