On 19th of January, Robert Haas committed patch:
Use abbreviated keys for faster sorting of text datums.
This commit extends the SortSupport infrastructure to allow operator
classes the option to provide abbreviated representations of Datums;
in the case of text, we abbreviate by taking the first few characters
of the strxfrm() blob. If the abbreviated comparison is insufficent
to resolve the comparison, we fall back on the normal comparator.
This can be much faster than the old way of doing sorting if the
first few bytes of the string are usually sufficient to resolve the
There is the potential for a performance regression if all of the
strings to be sorted are identical for the first 8+ characters and
differ only in later positions; therefore, the SortSupport machinery
now provides an infrastructure to abort the use of abbreviation if
it appears that abbreviation is producing comparatively few distinct
keys. HyperLogLog, a streaming cardinality estimator, is included in
this commit and used to make that determination for text.
Peter Geoghegan, reviewed by me.
Continue reading Waiting for 9.5 – Use abbreviated keys for faster sorting of text datums.
On 23rd of January, Alvaro Herrera committed patch:
vacuumdb: enable parallel mode
This mode allows vacuumdb to open several server connections to vacuum
or analyze several tables simultaneously.
Author: Dilip Kumar. Some reworking by Álvaro Herrera
Reviewed by: Jeff Janes, Amit Kapila, Magnus Hagander, Andres Freund
Continue reading Waiting for 9.5 – vacuumdb: enable parallel mode
Recently I saw this discussion on LinkedIn.
In there a guy asks whether modifying script while it's executing will change
the way it executes.
Continue reading Reloading of Perl script while it's running
This time the changes do not modify how the website works. But they make it simpler to deploy clone of explain.depesz.com on your own server.
Thanks to Petr A. Korobeinikov I got full automation for setting test/development/internal clones of the site. What was done previously manually, now can be done very fast using Vagrant or Puppet.
Great stuff, thanks Petr.
Continue reading Changes in explain.depesz.com