postgresql/doc
Alvaro Herrera d9d076222f
VACUUM: ignore indexing operations with CONCURRENTLY
As envisioned in commit c98763bf51, it is possible for VACUUM to
ignore certain transactions that are executing CREATE INDEX CONCURRENTLY
and REINDEX CONCURRENTLY for the purposes of computing Xmin; that's
because we know those transactions are not going to examine any other
tables, and are not going to execute anything else in the same
transaction.  (Only operations on "safe" indexes can be ignored: those
on indexes that are neither partial nor expressional).

This is extremely useful in cases where CIC/RC can run for a very long
time, because that used to be a significant headache for concurrent
vacuuming of other tables.

Reviewed-by: Matthias van de Meent <boekewurm+postgres@gmail.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Discussion: https://postgr.es/m/20210115133858.GA18931@alvherre.pgsql
2021-02-23 12:15:09 -03:00
..
src VACUUM: ignore indexing operations with CONCURRENTLY 2021-02-23 12:15:09 -03:00
KNOWN_BUGS
Makefile
MISSING_FEATURES
TODO