postgresql/doc
Alvaro Herrera 7526e10224 BRIN auto-summarization
Previously, only VACUUM would cause a page range to get initially
summarized by BRIN indexes, which for some use cases takes too much time
since the inserts occur.  To avoid the delay, have brininsert request a
summarization run for the previous range as soon as the first tuple is
inserted into the first page of the next range.  Autovacuum is in charge
of processing these requests, after doing all the regular vacuuming/
analyzing work on tables.

This doesn't impose any new tasks on autovacuum, because autovacuum was
already in charge of doing summarizations.  The only actual effect is to
change the timing, i.e. that it occurs earlier.  For this reason, we
don't go any great lengths to record these requests very robustly; if
they are lost because of a server crash or restart, they will happen at
a later time anyway.

Most of the new code here is in autovacuum, which can now be told about
"work items" to process.  This can be used for other things such as GIN
pending list cleaning, perhaps visibility map bit setting, both of which
are currently invoked during vacuum, but do not really depend on vacuum
taking place.

The requests are at the page range level, a granularity for which we did
not have SQL-level access; we only had index-level summarization
requests via brin_summarize_new_values().  It seems reasonable to add
SQL-level access to range-level summarization too, so add a function
brin_summarize_range() to do that.

Authors: Álvaro Herrera, based on sketch from Simon Riggs.
Reviewed-by: Thomas Munro.
Discussion: https://postgr.es/m/20170301045823.vneqdqkmsd4as4ds@alvherre.pgsql
2017-04-01 14:00:53 -03:00
..
src BRIN auto-summarization 2017-04-01 14:00:53 -03:00
bug.template Stamp HEAD as 10devel. 2016-08-15 13:49:49 -04:00
KNOWN_BUGS Remove extra newlines at end and beginning of files, add missing newlines 2010-08-19 05:57:36 +00:00
Makefile Remove maintainer-check target, fold into normal build 2013-10-10 20:11:56 -04:00
MISSING_FEATURES Remove extra newlines at end and beginning of files, add missing newlines 2010-08-19 05:57:36 +00:00
TODO Update URL. 2008-08-21 20:15:31 +00:00