From: Noah Misch <noah@leadboat.com>
To: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Cc: robertmhaas@gmail.com
Cc: pgsql-hackers@postgresql.org
Cc: 9erthalion6@gmail.com
Cc: andrew.dunstan@2ndquadrant.com
Cc: hlinnaka@iki.fi
Cc: michael@paquier.xyz
Subject: Re: [HACKERS] WAL logging problem in 9.4.3?
Date: Sun, 26 Jan 2020 20:22:01 -0800
Message-ID: <20200127042201.GA3119606@rfd.leadboat.com> (raw)
In-Reply-To: <20200121.184557.1462314355964996736.horikyota.ntt@gmail.com>
References: <20200115.171857.1170166613760719188.horikyota.ntt@gmail.com>
<20200116.142057.1250623796779593147.horikyota.ntt@gmail.com>
<20200119035139.GA2811524@rfd.leadboat.com>
<20200121.184557.1462314355964996736.horikyota.ntt@gmail.com>
Diffing the two latest versions of one patch:
> --- v32-0002-Fix-the-defect-1.patch 2020-01-18 14:32:47.499129940 -0800
> +++ v33-0002-Fix-the-defect-1.patch 2020-01-26 16:23:52.846391035 -0800
> +@@ -2978,8 +3054,8 @@ AssertPendingSyncs_RelationCache(void)
> + LOCKTAG_RELATION)
> + continue;
> + relid = ObjectIdGetDatum(locallock->tag.lock.locktag_field2);
> +- r = RelationIdGetRelation(relid);
> +- if (r == NULL)
> ++ r = RelationIdGetRelationCache(relid);
The purpose of this loop is to create relcache entries for rels locked in the
current transaction. (The "r == NULL" case happens for rels no longer visible
in catalogs. It is harmless.) Since RelationIdGetRelationCache() never
creates a relcache entry, calling it defeats that purpose.
RelationIdGetRelation() is the right function to call.
On Tue, Jan 21, 2020 at 06:45:57PM +0900, Kyotaro Horiguchi wrote:
> Three other fixes not mentined above are made. One is the useless
> rd_firstRelfilenodeSubid in the condition to dicide whether to
> preserve or not a relcache entry
It was not useless. Test case:
create table t (c int);
begin;
alter table t alter c type bigint; -- sets rd_firstRelfilenodeSubid
savepoint q; drop table t; rollback to q; -- forgets rd_firstRelfilenodeSubid
commit; -- assertion failure, after s/RelationIdGetRelationCache/RelationIdGetRelation/ discussed above
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To: pgsql-hackers@postgresql.org
Cc: noah@leadboat.com, horikyota.ntt@gmail.com, robertmhaas@gmail.com, 9erthalion6@gmail.com, andrew.dunstan@2ndquadrant.com, hlinnaka@iki.fi, michael@paquier.xyz
Subject: Re: [HACKERS] WAL logging problem in 9.4.3?
In-Reply-To: <20200127042201.GA3119606@rfd.leadboat.com>
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