Re: ExecForceStoreMinimalTuple leaks memory like there's no tomorrow
Hi, On 2019-04-18 19:04:09 -0700, Andres Freund wrote: > On 2019-04-15 22:46:56 -0400, Tom Lane wrote: > > Using HEAD, > > > > create table t1 as select generate_series(1,4000) id; > > vacuum analyze t1; > > explain select * from t1, t1 t1b where t1.id = t1b.id; > > -- should indicate a hash join > > explain analyze select * from t1, t1 t1b where t1.id = t1b.id; > > > > ... watch the process's memory consumption bloat. (It runs for > > awhile before that starts to happen, but eventually it goes to > > a couple of GB.) > > > > It looks to me like the problem is that ExecHashJoinGetSavedTuple > > calls ExecForceStoreMinimalTuple with shouldFree = true, and > > ExecForceStoreMinimalTuple's second code branch simply ignores > > the requirement to free the supplied tuple. > > Thanks for finding. The fix is obviously easy - but looking through the > code I think I found another similar issue. I'll fix both in one go > tomorrow. Pushed the combined fix for that. Thanks! Greetings, Andres Freund
Re: ExecForceStoreMinimalTuple leaks memory like there's no tomorrow
Hi, On 2019-04-15 22:46:56 -0400, Tom Lane wrote: > Using HEAD, > > create table t1 as select generate_series(1,4000) id; > vacuum analyze t1; > explain select * from t1, t1 t1b where t1.id = t1b.id; > -- should indicate a hash join > explain analyze select * from t1, t1 t1b where t1.id = t1b.id; > > ... watch the process's memory consumption bloat. (It runs for > awhile before that starts to happen, but eventually it goes to > a couple of GB.) > > It looks to me like the problem is that ExecHashJoinGetSavedTuple > calls ExecForceStoreMinimalTuple with shouldFree = true, and > ExecForceStoreMinimalTuple's second code branch simply ignores > the requirement to free the supplied tuple. Thanks for finding. The fix is obviously easy - but looking through the code I think I found another similar issue. I'll fix both in one go tomorrow. Greetings, Andres Freund
Re: ExecForceStoreMinimalTuple leaks memory like there's no tomorrow
On Mon, Apr 15, 2019 at 10:46:56PM -0400, Tom Lane wrote: > create table t1 as select generate_series(1,4000) id; > vacuum analyze t1; > explain select * from t1, t1 t1b where t1.id = t1b.id; > -- should indicate a hash join > explain analyze select * from t1, t1 t1b where t1.id = t1b.id; > > ... watch the process's memory consumption bloat. (It runs for > awhile before that starts to happen, but eventually it goes to > a couple of GB.) > > It looks to me like the problem is that ExecHashJoinGetSavedTuple > calls ExecForceStoreMinimalTuple with shouldFree = true, and > ExecForceStoreMinimalTuple's second code branch simply ignores > the requirement to free the supplied tuple. Open item added, as the root comes from 4da597ed. -- Michael signature.asc Description: PGP signature
