Re: Yet another fast GiST build

On Sun, Sep 20, 2020 at 05:10:05PM -0400, Tom Lane wrote:
> I wrote:
> > It appears that hyrax (CLOBBER_CACHE_ALWAYS) is not very happy
> > with this:
> > https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=hyrax&dt=2020-09-19%2021%3A27%3A23
>
> I reproduced that and traced it to a missing RelationOpenSmgr call.
> Fixed now.

This also appears to break checksums.

postgres=# CREATE TABLE pvactst (i INT, a INT[], p POINT) with (autovacuum_enabled = off);
postgres=# CREATE INDEX gist_pvactst ON pvactst USING gist (p);
postgres=# INSERT INTO pvactst SELECT i, array[1,2,3], point(i, i+1) FROM generate_series(1,1000) i;
WARNING: page verification failed, calculated checksum 34313 but expected 0
ERROR: invalid page in block 0 of relation base/12859/16389

I was able to make this work like so:

@@ -449,6 +450,7 @@ gist_indexsortbuild(GISTBuildState *state)

/* Write out the root */
PageSetLSN(pagestate->page, GistBuildLSN);
+ PageSetChecksumInplace(pagestate->page, GIST_ROOT_BLKNO, state->indexrel->rd_smgr);
smgrwrite(state->indexrel->rd_smgr, MAIN_FORKNUM, GIST_ROOT_BLKNO,
pagestate->page, true);
if (RelationNeedsWAL(state->indexrel))
@@ -555,6 +557,7 @@ gist_indexsortbuild_flush_ready_pages(GISTBuildState *state)

PageSetLSN(page, GistBuildLSN);

+ PageSetChecksumInplace(page, state->pages_written, state->indexrel->rd_smgr);
smgrextend(state->indexrel->rd_smgr,
MAIN_FORKNUM,
state->pages_written++,

--
Justin