I'm looking into upgrading a fairly busy system to 9.1. They use serializable mode for a few certain things, and suffer through some serialization errors as a result. While looking over the new serializable/SSI documentation, one thing that stood out is:
http://www.postgresql.org/docs/current/interactive/transaction-iso.html "The monitoring of read/write dependencies has a cost, as does the restart of transactions which are terminated with a serialization failure, but balanced against the cost and blocking involved in use of explicit locks and SELECT FOR UPDATE or SELECT FOR SHARE, Serializable transactions are the best performance choice for some environments." I agree it is better versus SELECT FOR, but what about repeatable read versus the new serializable? How much overhead is there in the 'monitoring of read/write dependencies'? This is my only concern at the moment. Are we talking insignificant overhead? Minor? Is it measurable? Hard to say without knowing the number of txns, number of locks, etc.? -- Greg Sabino Mullane g...@endpoint.com End Point Corporation PGP Key: 0x14964AC8
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