Em sáb., 5 de jun. de 2021 às 11:16, Ranier Vilela <ranier...@gmail.com> escreveu:
> > Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> writes: > > > > Now, while this patch does seem to work correctly, it raises a number > of > > > weird cpluspluscheck warnings, which I think are attributable to the > > > new macro definitions. I didn't look into it closely, but I suppose it > > > should be fixable given sufficient effort: > > > > Didn't test, but the first one is certainly fixable by adding a cast, > > and I guess the others might be as well. > > >I get no warnings with this one. I'm a bit wary of leaving > >VARDATA_COMPRESSED_GET_EXTSIZE unchanged, but at least nothing in this > >patch requires a cast there. > > Hi Alvaro. > > Please, would you mind testing with these changes. > I'm curious to see if anything improves or not. > 1. Add a const to the attr parameter. > 2. Remove the cmid variable (and store it). > 3. Add tail cut. > I think that https://github.com/postgres/postgres/commit/e6241d8e030fbd2746b3ea3f44e728224298f35b#diff-640a50de37a0dc027d9d1c7239e34aed53b184a8ec6e1f653694e458376b19fa still has space for improvements. If attr->attcompression is invalid, it doesn't matter, it's better to decompress. Besides if it is invalid, currently default_toast_compression is not stored in attr->attcompression. I believe this version should be a little faster. Since it won't double-scan the attributes if it's not really necessary. regards, Ranier Vilela
reduce_overhead-on-detoasteds_values.patch
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