Re: Yet another fast GiST build

[Justin Pryzby]

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