On Sat, May 09, 2020 at 06:48:59AM -0300, Ranier Vilela wrote:
Em sáb., 9 de mai. de 2020 às 01:45, Tom Lane <t...@sss.pgh.pa.us> escreveu:James Coleman <jtc...@gmail.com> writes: > There are always full sort groups before any prefix groups can happen, > so we know (even though the tooling doesn't) that the 2nd test can > never contradict the first. So maybe an assertion enforcing that would be appropriate? Untested, but: - if (fullsortGroupInfo->groupCount == 0 && - prefixsortGroupInfo->groupCount == 0) + if (fullsortGroupInfo->groupCount == 0) + { + Assert(prefixsortGroupInfo->groupCount == 0); continue; + }I agree, asserts always help.
That doesn't work, because the prefixSortGroupInfo is used before assignment, producing compile-time warnings. I've pushed a simpler fix without the assert. If we want to make this check, perhaps doing it in incremental sort itself would be better than doing it in explain. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
