Horton

Re: WIP: BRIN multi-range indexes

John Naylor <john.naylor@enterprisedb.com>

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From: John Naylor <john.naylor@enterprisedb.com>
To: Tomas Vondra <tomas.vondra@enterprisedb.com>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2021-01-26T18:40:43Z
Lists: pgsql-hackers 
Hi Tomas,
I took another look through the Bloom opclass portion (0004) with
sorted_mode omitted, and it looks good to me code-wise. I think this part
is close to commit-ready. I also did one more proofreading pass for
minor details.

+     rows per block). The default values is <literal>-0.1</literal>, and

+     greater than 0.0 and smaller than 1.0. The default values is 0.01,

s/values/value/

+ * bloom filter, we can easily and cheaply test wheter it contains values

s/wheter/whether/

+ * XXX We assume the bloom filters have the same parameters fow now. In the

s/fow/for/

+ * or null if it does not exists.

s/exists/exist/

+ * We do expect the bloom filter to eventually switch to hashing mode,
+ * and it's bound to be almost perfectly random, so not compressible.

Leftover from when it started out in sorted mode.

+ if ((m/8) > BLCKSZ)

It seems we need something more safe, to account for page header and tuple
header at least. As the comment before says, the filter will eventually not
be compressible. I remember we can't be exact here, with the possibility of
multiple columns, but we can leave a little slack space.

-- 
John Naylor
EDB: http://www.enterprisedb.com

Commits

  1. BRIN minmax-multi indexes

  2. BRIN bloom indexes

  3. Support the old signature of BRIN consistent function

  4. Remove unnecessary pg_amproc BRIN minmax entries

  5. Optimize allocations in bringetbitmap

  6. Move IS [NOT] NULL handling from BRIN support functions

  7. Pass all scan keys to BRIN consistent function at once

  8. Properly detoast data in brin_form_tuple