In case you're not familiar – there is a thing called LVM – it's a layer between physical disks, and filesystems, and allow certain interesting things, like extending, migrating, snapshotting and others.
At one of systems I've been dealing with, we stumbled upon specific requirement – change LV into striped. It took me a while to figure it out, so I'm writing it down, so I'll never have to research it again.
Continue reading Converting Logical Volume so that it's striped
On 8th of September, Alvaro Herrera committed patch:
Allow per-tablespace effective_io_concurrency Per discussion, nowadays it is possible to have tablespaces that have wildly different I/O characteristics from others. Setting different effective_io_concurrency parameters for those has been measured to improve performance. Author: Julien Rouhaud Reviewed by: Andres Freund
Continue reading Waiting for 9.6 – Allow per-tablespace effective_io_concurrency
On 7th of September, Jeff Davis committed patch:
Add log_line_prefix option 'n' for Unix epoch. Prints time as Unix epoch with milliseconds. Tomas Vondra, reviewed by Fabien Coelho.
Continue reading Waiting for 9.6 – Add log_line_prefix option ‘n' for Unix epoch.
On 2nd of September, Teodor Sigaev committed patch:
Allow usage of huge maintenance_work_mem for GIN build. Currently, in-memory posting list during GIN build process is limited 1GB because of using repalloc. The patch replaces call of repalloc to repalloc_huge. It increases limit of posting list from 180 millions (1GB / sizeof(ItemPointerData)) to 4 billions limited by maxcount/count fields in GinEntryAccumulator and subsequent calls. Check added. Also, fix accounting of allocatedMemory during build to prevent integer overflow with maintenance_work_mem > 4GB. Robert Abraham <robert.abraham86@googlemail.com> with additions by me
Continue reading Waiting for 9.6 – Allow usage of huge maintenance_work_mem for GIN build.
There exists an extension to PostgreSQL, which lets you use hypothetical indexes.
What are there? That's simple – these are indexes that don't really exist. So what good are they?
Let's see.
On 30th of July, Andrew Dunstan committed patch:
Add IF NOT EXISTS processing to ALTER TABLE ADD COLUMN Fabrízio de Royes Mello, reviewed by Payal Singh, Alvaro Herrera and Michael Paquier.
Continue reading Waiting for 9.6 – Add IF NOT EXISTS processing to ALTER TABLE ADD COLUMN
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.
Continue reading Waiting for 9.6 – Add new function pg_notification_queue_usage.
On 7th of July, Andres Freund committed patch:
Add psql PROMPT variable showing the pid of the connected to backend. The substitution for the pid is %p. Author: Julien Rouhaud Discussion: <a href="http://git.postgresql.org/gitweb/?p=postgresql.git;a=object;h=116262CF971C844FB6E793F8809B51C6E99D48">116262CF971C844FB6E793F8809B51C6E99D48</a>@BPXM02GP.gisp.nec.co.jp
On 3rd of July, Tom Lane committed patch:
Add psql \ev and \sv commands for editing and showing view definitions. These are basically just like the \ef and \sf commands for functions. Petr Korobeinikov, reviewed by Jeevan Chalke, some changes by me
Recently I noticed that more and more cases that I deal with could use some partitioning. And while theoretically most people know about it, it's definitely not a very well-understood feature, and sometimes people are scared of it.
So, I'll try to explain, to my best knowledge, what it is, why one would want to use it, and how to actually make it happen.