postgresql/contrib/pg_walinspect
Robert Haas 05d4cbf9b6 Increase width of RelFileNumbers from 32 bits to 56 bits.
RelFileNumbers are now assigned using a separate counter, instead of
being assigned from the OID counter. This counter never wraps around:
if all 2^56 possible RelFileNumbers are used, an internal error
occurs. As the cluster is limited to 2^64 total bytes of WAL, this
limitation should not cause a problem in practice.

If the counter were 64 bits wide rather than 56 bits wide, we would
need to increase the width of the BufferTag, which might adversely
impact buffer lookup performance. Also, this lets us use bigint for
pg_class.relfilenode and other places where these values are exposed
at the SQL level without worrying about overflow.

This should remove the need to keep "tombstone" files around until
the next checkpoint when relations are removed. We do that to keep
RelFileNumbers from being recycled, but now that won't happen
anyway. However, this patch doesn't actually change anything in
this area; it just makes it possible for a future patch to do so.

Dilip Kumar, based on an idea from Andres Freund, who also reviewed
some earlier versions of the patch. Further review and some
wordsmithing by me. Also reviewed at various points by Ashutosh
Sharma, Vignesh C, Amul Sul, Álvaro Herrera, and Tom Lane.

Discussion: http://postgr.es/m/CA+Tgmobp7+7kmi4gkq7Y+4AM9fTvL+O1oQ4-5gFTT+6Ng-dQ=g@mail.gmail.com
2022-09-27 13:25:21 -04:00
..
expected Increase width of RelFileNumbers from 32 bits to 56 bits. 2022-09-27 13:25:21 -04:00
sql Increase width of RelFileNumbers from 32 bits to 56 bits. 2022-09-27 13:25:21 -04:00
.gitignore
Makefile
meson.build meson: Add initial version of meson based build system 2022-09-21 22:37:17 -07:00
pg_walinspect--1.0.sql Use float8 datatype for percentiles in pg_walinspect stat functions 2022-09-12 10:01:00 +02:00
pg_walinspect.c Use float8 datatype for percentiles in pg_walinspect stat functions 2022-09-12 10:01:00 +02:00
pg_walinspect.control
walinspect.conf