Couple of days earlier I wrote about tools to run tasks in db at scheduled times.
In writing this I missed pg_cron. So let's look into it now.
Continue reading How to run some tasks without user intervention, at specific times? – part 2
Month: January 2021
Waiting for PostgreSQL 14 – Add pg_stat_database counters for sessions and session time
On 17th of January 2021, Magnus Hagander committed patch:
Add pg_stat_database counters for sessions and session time This add counters for number of sessions, the different kind of session termination types, and timers for how much time is spent in active vs idle in a database to pg_stat_database. Internally this also renames the parameter "force" to disconnect. This was the only use-case for the parameter before, so repurposing it to this mroe narrow usecase makes things cleaner than inventing something new. Author: Laurenz Albe Reviewed-By: Magnus Hagander, Soumyadeep Chakraborty, Masahiro Ikeda Discussion: https://postgr.es/m/b07e1f9953701b90c66ed368656f2aef40cac4fb.camel@cybertec.at
Are there limits to partition counts?
How to run some tasks without user intervention, at specific times?
Every now and then someone complains (me included) that PostgreSQL doesn't have job scheduler.
This is true, to some extent. I'll try to show you couple of approaches to solving this particular problem.
Continue reading How to run some tasks without user intervention, at specific times?
Waiting for PostgreSQL 14 – Add idle_session_timeout.
On 6th of January 2021, Tom Lane committed patch:
Add idle_session_timeout. This GUC variable works much like idle_in_transaction_session_timeout, in that it kills sessions that have waited too long for a new client query. But it applies when we're not in a transaction, rather than when we are. Li Japin, reviewed by David Johnston and Hayato Kuroda, some fixes by me Discussion: https://postgr.es/m/763A0689-F189-459E-946F-F0EC4458980B@hotmail.com
Continue reading Waiting for PostgreSQL 14 – Add idle_session_timeout.
Waiting for PostgreSQL 14 – Report progress of COPY commands
On 6th of January 2021, Tomas Vondra committed patch:
Report progress of COPY commands This commit introduces a view pg_stat_progress_copy, reporting progress of COPY commands. This allows rough estimates how far a running COPY progressed, with the caveat that the total number of bytes may not be available in some cases (e.g. when the input comes from the client). Author: Josef Šimánek Reviewed-by: Fujii Masao, Bharath Rupireddy, Vignesh C, Matthias van de Meent Discussion: https://postgr.es/m/CAFp7QwqMGEi4OyyaLEK9DR0+E+oK3UtA4bEjDVCa4bNkwUY2PQ@mail.gmail.com Discussion: https://postgr.es/m/CAFp7Qwr6_FmRM6pCO0x_a0mymOfX_Gg+FEKet4XaTGSW=LitKQ@mail.gmail.com
Continue reading Waiting for PostgreSQL 14 – Report progress of COPY commands
How to limit rows to at most N per category – fix
A bit ago I wrote a blog post that was supposed to show how to keep number of rows in table to N per some category.
Unfortunately, I overlooked a problem related to concurrency.
Continue reading How to limit rows to at most N per category – fix
Fixes on why-upgrade.depesz.com
In case you're not familiar with this site, why-upgrade.depesz.com shows you aggregated changelog between any two releases, with optionally searching for some keywords.
Yesterday azeem on irc pointed me towards a problem on why-upgrade.depesz.com. Specifically, when displaying changes from 9.5.24 to 13.1 site showed 30 security fixes. But in reality there should be only 10.
Reconnecting to SSH servers
In my work I'm often in situation where I want to restart remote server, and then immediately connect to it over ssh.
This can be done by repeating ssh HOST in shell, but it gets tedious.