On 6th of February 2020, Michael Paquier committed patch:
Add leader_pid to pg_stat_activity
This new field tracks the PID of the group leader used with parallel
query. For parallel workers and the leader, the value is set to the
PID of the group leader. So, for the group leader, the value is the
same as its own PID. Note that this reflects what PGPROC stores in
shared memory, so as leader_pid is NULL if a backend has never been
involved in parallel query. If the backend is using parallel query or
has used it at least once, the value is set until the backend exits.
Author: Julien Rouhaud
Reviewed-by: Sergei Kornilov, Guillaume Lelarge, Michael Paquier, Tomas
Continue reading Waiting for PostgreSQL 13 – Add leader_pid to pg_stat_activity
Recently I was in a situation where autovacuum couldn't keep up with changes. To solve the problem I finally decided to manually vacuum analyze all tables (manual vacuum/analyze is faster than one ran by autovacuum daemon).
But it irritated me that I didn't have ready way to check which tables are waiting for autovacuum to work on them.
So, I wrote it.
Continue reading Which tables should be auto vacuumed or auto analyzed?
In 2018 Lluad created wiki page with couple of rules about what not to do.
Since then there have been 30 changes, done by nine more people.
Based on some conversation on irc I figured I can write a tool to automatically check these rules. Or at least – most of them.
Continue reading Don't do these things in PostgreSQL
On 25th of January 2020, Dean Rasheed committed patch:
Add functions gcd() and lcm() for integer and numeric types.
These compute the greatest common divisor and least common multiple of
a pair of numbers using the Euclidean algorithm.
Vik Fearing, reviewed by Fabien Coelho.
Continue reading Waiting for PostgreSQL 13 – Add functions gcd() and lcm() for integer and numeric types.
Warsaw PostgreSQL Users Group (facebook , meetup) uploaded a song to youtube: Nothing Compares To VACUUM 🙂
On 20th of January 2020, Amit Kapila committed patch:
Allow vacuum command to process indexes in parallel.
This feature allows the vacuum to leverage multiple CPUs in order to
process indexes. This enables us to perform index vacuuming and index
cleanup with background workers. This adds a PARALLEL option to VACUUM
command where the user can specify the number of workers that can be used
to perform the command which is limited by the number of indexes on a
table. Specifying zero as a number of workers will disable parallelism.
This option can't be used with the FULL option.
Each index is processed by at most one vacuum process. Therefore parallel
vacuum can be used when the table has at least two indexes.
The parallel degree is either specified by the user or determined based on
the number of indexes that the table has, and further limited by
max_parallel_maintenance_workers. The index can participate in parallel
vacuum iff it's size is greater than min_parallel_index_scan_size.
Author: Masahiko Sawada and Amit Kapila
Mahendra Singh and Sergei Kornilov
Continue reading Waiting for PostgreSQL 13 – Allow vacuum command to process indexes in parallel.
Title: Waiting for PostgreSQL 13 – ALTER TABLE … ALTER COLUMN … DROP EXPRESSION
On 14th of January 2020, Peter Eisentraut committed patch:
ALTER TABLE ... ALTER COLUMN ... DROP EXPRESSION
Add an ALTER TABLE subcommand for dropping the generated property from
a column, per SQL standard.
Continue reading Waiting for PostgreSQL 13 – ALTER TABLE … ALTER COLUMN … DROP EXPRESSION
Recently, on irc, there have been some talks with people using various pg_dump/pg_dumpall calls to get dumps of database.
I voiced my ideas, but figured it could be good subject for a blog post.
Continue reading How to effectively dump PostgreSQL databases
Just pushed new version of explain.depesz.com site.
- most importantly : changed favicon to be more related to site
- extended, quite a lot, help page
- added a way to embed explains on your page
Continue reading Changes on explain.depesz.com