There is this idea that from 9.5 we will be able to upgrade pg clusters to newer, major, version, without downtime (well, almost), thanks to magic of logical replication. Sounds very promising, so I figured - I'll test it. To some ...

On 17th of July, Robert Haas committed patch: Add new function pg_notification_queue_usage. This tells you what fraction of NOTIFY's queue is currently filled. Brendan Jurd, reviewed by Merlin Moncure and Gurjeet Singh. A few further tweaks by me.

On 23rd of March, Heikki Linnakangas committed patch: Add pg_rewind, for re-synchronizing a master server after failback. Earlier versions of this tool were available (and still are) on github. Thanks to Michael Paquier, Alvaro Herrera, Peter Eisentraut, Amit Kapila, and Satoshi Nagayasu for review.

One of my clients is upgrading some servers. The procedure we have took some time to get to current state, and we found some potential problems, so decided to write more about it.

I had to deal with this question, or some version of it, quite a few times. So, decided to write a summary on what one could (or should) do, after data is in database, and application is running. Namely - ...

On 22nd of August, Alvaro Herrera committed patch: Implement ALTER TABLE .. SET LOGGED / UNLOGGED This enables changing permanent (logged) tables to unlogged and vice-versa. (Docs for ALTER TABLE / SET TABLESPACE got shuffled in an order that hopefully makes more sense than the ...

On 3rd of March, Robert Haas committed patch: Introduce logical decoding. This feature, building on previous commits, allows the write-ahead log stream to be decoded into a series of logical changes; that is, inserts, updates, and deletes and the transactions which contain them. It is ...

On 28th of January, Fujii Masao committed patch: Add pg_stat_archiver statistics view. This view shows the statistics about the WAL archiver process's activity. Gabriele Bartolini, reviewed by Michael Paquier, refactored a bit by me.

On 12th of December, Simon Riggs committed patch: Allow time delayed standbys and recovery Set min_recovery_apply_delay to force a delay in recovery apply for commit and restore point WAL records. Other records are replayed immediately. Delay is measured between WAL record time and local ...

On 11th of December, Robert Haas committed patch: Add new wal_level, logical, sufficient for logical decoding. When wal_level=logical, we'll log columns from the old tuple as configured by the REPLICA IDENTITY facility added in commit 07cacba983ef79be4a84fcd0e0ca3b5fcb85dd65. This makes it possible a properly-configured logical replication ...