Hi hackers, Currently we don't generate parallel plans in SERIALIZABLE. What problems need to be solved to be able to do that? I'm probably steamrolling over a ton of subtleties and assumptions here, but it occurred to me that a first step might be something like this:
1. Hand the leader's SERIALIZABLEXACT to workers. 2. Make sure that workers don't release predicate locks. 3. Make sure that the leader doesn't release predicate locks until after the workers have finished accessing the leader's SERIALIZABLEXACT. I think this is already the case. See attached 5 minute hack. Need to audit predicate.c for cases where MySerializableXact might be modified without suitable locking, and probably sprinkle assertions all over the place that workers don't reach certain places etc. I wonder what horrible things might happen as a result of workers running with a SERIALIZABLEXACT that contains the leader's vxid and other such things. I'd love to figure all this out in time for one of the later CFs in this cycle. Any thoughts? -- Thomas Munro http://www.enterprisedb.com
ssi-parallel-hack.patch
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