On 23/4/2024 11:16, Imseih (AWS), Sami wrote:
FWIW, I'd like to think that we could improve the situation, requiring
a mix of calling pgstat_report_query_id() while feeding on some query
IDs retrieved from CachedPlanSource->query_list. I have not in
details looked at how much could be achieved, TBH.
I was dealing with this today and found this thread. I spent some time
looking at possible solutions.
In the flow of extended query protocol, the exec_parse_message
reports the queryId, but subsequent calls to exec_bind_message
and exec_execute_message reset the queryId when calling
pgstat_report_activity(STATE_RUNNING,..) as you can see below.
/*
* If a new query is started, we reset the query identifier as it'll only
* be known after parse analysis, to avoid reporting last query's
* identifier.
*/
if (state == STATE_RUNNING)
beentry->st_query_id = UINT64CONST(0);
So, I think the simple answer is something like the below.
Inside exec_bind_message and exec_execute_message,
the query_id should be reported after pg_report_activity.
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 76f48b13d2..7ec2df91d5 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -1678,6 +1678,7 @@ exec_bind_message(StringInfo input_message)
debug_query_string = psrc->query_string;
pgstat_report_activity(STATE_RUNNING, psrc->query_string);
+ pgstat_report_query_id(linitial_node(Query, psrc->query_list)->queryId,
true);
set_ps_display("BIND");
@@ -2146,6 +2147,7 @@ exec_execute_message(const char *portal_name, long max_rows)
debug_query_string = sourceText;
pgstat_report_activity(STATE_RUNNING, sourceText);
+ pgstat_report_query_id(portal->queryDesc->plannedstmt->queryId, true);
cmdtagname = GetCommandTagNameAndLen(portal->commandTag, &cmdtaglen);
thoughts?
In exec_bind_message, how can you be sure that queryId exists in
query_list before the call of GetCachedPlan(), which will validate and
lock the plan? What if some OIDs were altered in the middle?
--
regards, Andrei Lepikhov
