Starting new blog series – explanation of various configuration parameters.
I will of course follow no schedule or order – if I'd had to – it would be my job, and in this way – it's fun.
First configuration parameter to write about is checkpoint_completion_target.
Continue reading Understanding postgresql.conf : checkpoint_completion_target
On 7th of October Alvaro Herrera committed his own patch, which adds quite interesting possibilty:
Make it possibly to specify GUC params per user and per database.
Create a new catalog pg_db_role_setting where they are now stored, and better
encapsulate the code that deals with settings into its realm. The old
datconfig and rolconfig columns are removed.
psql has gained a \drds command to display the settings.
Backwards compatibility warning: while the backwards-compatible system views
still have the config columns, they no longer completely represent the
configuration for a user or database.
Catalog version bumped.
Continue reading Waiting for 8.5 – GUC per user and database
This post has been updated with new code that uses temporary table – the code is at the end of post!
There was this question on Stack Overflow.
For future reference: guy asked how to do session variables – i.e. something he could define once in session, and later reuse in standard sql queries – without modifying postgresql.conf – so usage of custom_variable_classes is forbidden 🙂
While I don't actually see why somebody would want to avoid modifying its postgresql.conf (short of “it's shared hosting and I don't have superuser privileges"), I thought that it will be rather simple, and at the same time, rather interesting.
So, let's do it:
Continue reading Getting session variables without touching postgresql.conf
Also yesterday, and also Peter Eisentraut, committed patch by Guillaume Smet, which:
Add log_line_prefix placeholder %e to contain the current SQL state
Author: Guillaume Smet
Continue reading Waiting for 8.5 – Add log_line_prefix placeholder %e to contain the current SQL state