"Joshua D. Drake" <jd@xxxxxxxxxxxxxxxxx> writes: > Tom Lane wrote: >> "Joshua D. Drake" <jd@xxxxxxxxxxxxxxxxx> writes: >>> Tom Lane wrote: >>>> "Joshua D. Drake" <jd@xxxxxxxxxxxxxxxxx> writes: >>>>> SERIALIZABLE is really slow :). >>>> Say what? If anything it's probably faster than READ COMMITTED, because >>>> it doesn't take as many snapshots. But the difference is likely down in >>>> the noise anyway. >> >>> Not in production it isn't. >> >> Well, I can believe that specific applications might be slower overall >> due to having to retry transactions that get serialization failures, >> or perhaps because they take more locks to prevent such failures. >> But it's not slower as far as the database engine is concerned. > > Well I can only speak to live production loads. I have never profiled > the difference from that low of a level. I can definitely say that in a > standard web app, under velocity, serializable is a huge performance killer. Are you having to retry after serialization failures frequently? There's no reason for an individual transaction to take longer in SERIALIZABLE mode. In fact I believe SERIALIZABLE mode is actually measurably faster in benchmarks but haven't run one in READ COMMITTED mode recently (for that reason). -- Gregory Stark EnterpriseDB http://www.enterprisedb.com ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org/
