Re: Using user mapping OID as hash key for connection hash

On Wed, Jan 27, 2016 at 6:32 AM, Ashutosh Bapat
<ashutosh.bapat@enterprisedb.com> wrote:
> As discussed in postgres_fdw join pushdown thread [1], for two different
> effective local users which use public user mapping we will be creating two
> different connections to the foreign server with the same credentials.
>
> Robert suggested [2] that we should use user mapping OID as the connection
> cache key instead of current userid and serverid.
>
> There are two patches attached here:
> 1. pg_fdw_concache.patch.short - shorter version of the fix. Right now
> ForeignTable, ForeignServer have corresponding OIDs saved in these
> structures. But UserMapping doesn't. Patch adds user mapping OID as a member
> to this structure. This member is then used as key in GetConnection().
> 2. pg_fdw_concache.patch.large - most of the callers of GetConnection() get
> ForeignServer object just to pass it to GetConnection(). GetConnection can
> obtain ForeignServer by using serverid from UserMapping and doesn't need
> ForeignServer to be an argument. Larger version of patch has this change.

The long form seems like a good idea, so I committed that one.

-- 
Robert Haas
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