Re: [PATCHES] Implementing RESET CONNECTION ... - Mailing list pgsql-hackers
From | Bruce Momjian |
---|---|
Subject | Re: [PATCHES] Implementing RESET CONNECTION ... |
Date | |
Msg-id | 200604251419.k3PEJfL16403@candle.pha.pa.us Whole thread Raw |
Responses |
Re: [PATCHES] Implementing RESET CONNECTION ...
Re: [PATCHES] Implementing RESET CONNECTION ... |
List | pgsql-hackers |
OK, what would people like done with this patch? Our TODO list has: * -Add RESET CONNECTION command to reset all session state This would include resetting of all variables (RESET ALL), droppingof temporary tables, removing any NOTIFYs, cursors, open transactions, prepared queries, currval()s, etc. Thiscould be used for connection pooling. We could also change RESET ALL to have this functionality. The difficult ofthis features is allowing RESET ALL to not affect changes made by the interface driver for its internal use. One idea is for this to be a protocol-only feature. Another approach is to notify the protocol when a RESET CONNECTION commandis used. This patch does everything except reset currval(), but the big missing item is that it doesn't handle the protocol issues outlined in the TODO item. However, there also has been very little discussion on exactly how the protocol stuff would work. Should we add it for 8.2 and see if we get any problem reports? --------------------------------------------------------------------------- > I have backed out the patch until there is more discussion. > > I now see that the CC list had an incorrect entry for the patches list, > so I am unsure if others have seen this patch thoroughly. --------------------------------------------------------------------------- Hans-J�rgen Sch�nig wrote: > We have implemented a patch which can be used by connection pools for > instance. > RESECT CONNECTION cleans up a backend so that it can be reused. > Temp tables, LISTEN / NOTIFY stuff, WITH HOLD cursors, open > transactions, prepared statements and GUCs are cleaned up. > I hope we have not missed important per-backend information. > > test=# BEGIN; > BEGIN > test=# RESET CONNECTION; > RESET > test=# COMMIT; > WARNING: there is no transaction in progress > COMMIT > test=# PREPARE myplan(int, int) AS SELECT $1 + $2; > PREPARE > test=# RESET CONNECTION; > RESET > test=# EXECUTE myplan(1, 2); > ERROR: prepared statement "myplan" does not exist > test=# > test=# DECLARE mycur CURSOR WITH HOLD FOR SELECT relname FROM pg_class; > DECLARE CURSOR > test=# FETCH NEXT FROM mycur; > relname > --------- > views > (1 row) > > test=# RESET CONNECTION; > RESET > test=# FETCH NEXT FROM mycur; > ERROR: cursor "mycur" does not exist > test=# CREATE TEMP TABLE mytmp (id int4); > CREATE TABLE > test=# RESET CONNECTION; > RESET > test=# INSERT INTO mytmp VALUES (10); > ERROR: relation "mytmp" does not exist > > > All regression tests passed. > It would be nice if we had this in 8.1. > > Best regards, > > Hans > > > -- > Cybertec Geschwinde u Schoenig > Schoengrabern 134, A-2020 Hollabrunn, Austria > Tel: +43/660/816 40 77 > www.cybertec.at, www.postgresql.at > -- Bruce Momjian http://candle.pha.pa.us EnterpriseDB http://www.enterprisedb.com + If your life is a hard drive, Christ can be your backup. + ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend -- Bruce Momjian http://candle.pha.pa.us EnterpriseDB http://www.enterprisedb.com + If your life is a hard drive, Christ can be your backup. +
pgsql-hackers by date: