On 2015-09-02 PM 04:07, Albe Laurenz wrote: > Amit Langote wrote: >> On 2015-09-02 PM 03:25, Amit Kapila wrote: >>> Will it handle deadlocks across different table partitions. Consider >>> a case as below: >>> >>> T1 >>> 1. Updates row R1 of T1 on shard S1 >>> 2. Updates row R2 of T2 on shard S2 >>> >>> T2 >>> 1. Updates row R2 of T2 on shard S2 >>> 2. Updates row R1 of T1 on shard S1 > >> As long as shards are processed in the same order in different >> transactions, ISTM, this issue should not arise? I can imagine it becoming >> a concern if parallel shard processing enters the scene. Am I missing >> something? > > That would only hold for a single query, right? > > If 1. and 2. in the above example come from different queries within one > transaction, you cannot guarantee that shards are processed in the same order. > > So T1 and T2 could deadlock. >
Sorry, I failed to see why that would be the case. Could you elaborate? Thanks, Amit -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
