Tom Lane wrote:
> As far as avoiding overhead goes, here's what I'm thinking:
>
> * The Values RTE node should contain a list of lists of bare
> expressions, without TargetEntry decoration (you probably do not
> need ResTarget in the raw parse tree for VALUES, either).
>
> * The ValuesScan plan node will just reference this list-of-lists
> (avoiding making a copy). It will need to contain a targetlist
> because all plan nodes do, but the base version of that will just
> be a trivial "Var 1", "Var 2", etc. (The planner might replace that
> with a nontrivial targetlist in cases such as the example above.)
I wanted to post an updated patch even though there are still things not
working again after conversion to bare expressions. Note that I hacked
enough of the executor stuff so I could test my changes on the parser
area. The basic "INSERT ... VALUES (...), (...), ..." does work, but
without DEFAULT again :-(.
The good news is that from a memory and perfomance standpoint, my simple
test now shows us outperforming mysql:
$loopcount = 1000000;
Postgres:
multi-INSERT-at-once Elapsed time is 12 seconds
~420MB
MySQL:
multi-INSERT-at-once Elapsed time is 17 seconds
~600MB
$loopcount = 2000000;
Postgres:
multi-INSERT-at-once Elapsed time is 29 seconds
~730MB
MySQL:
multi-INSERT-at-once Elapsed time is 37 seconds
~1.2GB (this one is from memory -- I didn't write it in my notes)
Joe
