As you perhaps know, explain.depesz.com has anonymization feature.
Couple of days ago Filip contacted me and sent a patch that stopped anonymization of typecasts.
I thought about the patch, and what it achieves, changed it's internals, but kept the effect. And today, it got released.
Continue reading Change in anonymization of plans on explain.depesz.com
During last months I wrote some tools to help me with my daily duties.
I'd like to let you know you about them, as you might find them useful.
So, here we go:
Continue reading Some new tools for PostgreSQL or around PostgreSQL
On 19t of January, Magnus Hagander committed patch:
Separate state from query string in pg_stat_activity
This separates the state (running/idle/idleintransaction etc) into
it's own field ("state"), and leaves the query field containing just
query text.
The query text will now mean "current query" when a query is running
and "last query" in other states. Accordingly,the field has been
renamed from current_query to query.
Since backwards compatibility was broken anyway to make that, the procpid
field has also been renamed to pid - along with the same field in
pg_stat_replication for consistency.
Scott Mead and Magnus Hagander, review work from Greg SmithContinue reading Waiting for 9.2 – split of current_query in pg_stat_activity
On 19t of January, Heikki Linnakangas committed patch:
Make pg_relation_size() and friends return NULL if the object doesn't exist. That avoids errors when the functions are used in queries like "SELECT pg_relation_size(oid) FROM pg_class", and a table is dropped concurrently. Phil Sorber
Continue reading Waiting for 9.2 – NULLS from pg_*_size() functions
Just released version 0.3.0 of our tool for handling WAL based replication in PostgreSQL – OmniPITR.
Version jump is related to addition of another tool – omnipitr-synch. This tool is used to copy PostgreSQL data dir (including all tablespaces of course) to remote location(s).
While this process is usually simple (call pg_start_backup(), transfer data, call pg_stop_backup()), thanks to the tool it can be wrapped as single call, with standardized logging, and tested logic. It also makes it trivial, and cheap, to setup more than one new slave at a time, without need to read data off master more than once.
If you have production DB servers, chances are you're running variant of these queries:
SELECT sum(pg_relation_size(oid)) from pg_class where relkind = 'i' SELECT sum(pg_relation_size(oid)) from pg_class where relkind = 'r'
To get summarized size of tables and/or indexes in your database (for example for graphing purposes).
This (getting pg_relation_size for rows in pg_class) has one problem – it can lock, or it can fail.
Continue reading Tips N' Tricks – getting sizes of relations without locks
I got asked on irc to show some examples how to use recursive CTE. Apparently my previous post wasn't good enough 🙂
I think that most of the users will use recursive cte to deal with trees I decided to show how to use it, even though it's not my favorite approach to dealing with trees in SQL.
Continue reading r/trees ( recursive trees, what did you think about? )
On 14h of December, Andrew Dunstan committed patch:
Add --exclude-table-data option to pg_dump. Andrew Dunstan, reviewed by Josh Berkus, Robert Haas and Peter Geoghegan. This allows dumping of a table definition but not its data, on a per table basis. Table name patterns are supported just as for --exclude-table.
Continue reading Waiting for 9.2 – excluding data of table from dump
( title, in case you don't know, comes from excellent “movie" about databases )
The secret ingredient is of course sharding.
Can we do sharding in PostgreSQL? First, let's define what sharding is:
Continue reading The secret ingredient in the webscale sauce
Just released version 0.2.0 of OmniPITR. There is one important change – that is OmniPITR backup programs can now create checksum files for backups.
Details in docs, but the basic idea is that to all the other options to omnipitr-backup-{master,slave} we added (Phil Sorber to be exact) –digest option, which lets you specify that you want some checksums (md5, sha1, sha2).