Some time ago someone posted on Reddit that they have problems adding Polish configuration to their PostgreSQL.
While checking it, I found some interesting news. And of course figured out how to have Polish configuration…
Tag: howto
Human/version sort in PostgreSQL – revisited
Couple of months ago I wrote how to do human sort in Pg by using arrays, and splitting string.
This works, but Matt mentioned in comments that it could be done with ICU collations.
So I looked into it …
Continue reading Human/version sort in PostgreSQL – revisited
Human/version sort in PostgreSQL
Ever been in situation where you had to sort data that is partially text, and partially numerical?
Like invoice numbers: prefix-9, prefix-10, prefix-11, other-5, other-20 ? Normally you can't do order by as you will get them in wrong order: other-20 ⇒ other-5 ⇒ prefix-10 ⇒ prefix-11 ⇒ prefix-9. Can something be done with it?
Why is my WAL directory so large?
This problem happened recently to couple of people on various Pg support channels, so I figured I can write a bit more about it, so that in future I have a place where I can refer people to 🙂
Variables in psql, how to use them?
psql, the database client for PostgreSQL has, since forever, support for variables.
These let you write certain queries in a way that is safe even when getting params from “outside".
Let's see what can be done with it…
How to get a row, and all of it’s dependencies?
This question was asked at least twice on some support channel. Getting a row is trivial: select * from table where id = ?. But what about dependencies – the rows that this exported row references?
Decided to take a look at this task.
Continue reading How to get a row, and all of it's dependencies?
Can you use fzf for psql history?
FZF is quite popular tool for fuzzy string finder. Very helpful for checking history of commands.
But, can I use it in psql?
Picking random element, with weights
Whenever I'm doing some testing I need sample data. Easiest way to do it is to generate data using some random/generate_series queries.
But what if I need specific frequencies?
For example, I need to generate 10,000,000 rows, where there will be 10% of ‘a', 20% of ‘b', and the rest will be split equally between ‘c' and ‘d'?
How to log selects from specific table?
Starting with Pg – where are logs?
Just so that it will be perfectly clear: the logs I have in mind are the ones for DBAs to read – with slow queries, errors, and other interesting information.
So, how does one find them?