2014-05-23 21:24 GMT+02:00 Simon Riggs <si...@2ndquadrant.com>: > On 23 May 2014 10:40, Tom Lane <t...@sss.pgh.pa.us> wrote: > > > If we're pulling syntax out of the air it'd be nice if we could avoid > > adding new keywords to the grammar. > > Oracle, SQLServer and DB2 have this capability. MySQL does not. > > SQLServer implements that using the table hint of READPAST. Since that > whole syntax area is radically different to what we have, it isn't > easy to maintain code compatibility. > > DB2 z/OS 10 provides SKIP LOCKED DATA clause to allow moving past > already locked rows. That's fairly recent and I don't believe there > will be many programs using that. DB2 UDB supports some complex > functionality using DB2_SKIPINSERTED, DB2_EVALUNCOMMITTED and > DB2_SKIPDELETED, all of which is complex and mostly exists for > benchmarks, AFAICS. > > Oracle uses both SKIP LOCKED and NOWAIT. > > PostgreSQL already chose to follow the Oracle syntax when we > implemented NOWAIT. So my proposal is that we follow the Oracle syntax > again and use the words SKIP LOCKED. > > I don't see any advantage in inventing new syntax that leaves us > incompatible with Oracle, nor do I see any need to be compatible with > both Oracle and DB2 since the latter is much less likely to gain us > anything in practice. >
+1 Pavel > > -- > Simon Riggs http://www.2ndQuadrant.com/ > PostgreSQL Development, 24x7 Support, Training & Services > > > -- > Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-hackers >
