Daniel Westermann

The WAL segment size becomes changeable in PostgreSQL 11

Up to PostgreSQL 10 the wal segment size was fixed once PostgreSQL was compiled and installed. When you wanted to have something else than the default you needed to tell that to the configure command when building from source, e.g.

The same MAC address for two interfaces on the same host?

Yes, sounds strange, but exactly this is what we faced today. In the end it is clear and not strange anymore but for a moment we really thought we are hitting a bug in the operating system, which was RedHat(…)

When you execute the same statement thousands of times -> prepare it

Every time you send a SQL statement to PostgreSQL it must be parsed. Parsing is fast, yes, but parsing the same statement a thousand times can quickly sum up to quite some time the database could spend for something else.

Updating the partition key now works in PostgreSQL 11

In the last post about partitioning improvements in PostgreSQL 11 we talked about unique indexes and primary keys on partitioned tables. Both did not work in PostgreSQL 10 but now do in PostgreSQL 11. Another operation that(…)

What is the maximum in list size in PostgreSQL?

Yesterday, while being at a customer, an interesting question popped up: What is the maximum of in list values in PostgreSQL? I couldn't answer although I never read somewhere that there is a limit. The following is for fun only(…)

Local partitioned indexes in PostgreSQL 11

When declarative partitioning was introduced with PostgreSQL 10 this was a big step forward. But as always with big new features some things do not work in PostgreSQL 10 which now get resolved in PostgreSQL 11. One of those are(…)

pg_basebackup and redirecting progress messages to a file

Recently I came over that commit and wondered what that is about. The answer is quite simple but I didn't know that this issue existed. Basically it is about how progress messages are written to screen and(…)

PostgreSQL 11: Procedures and transaction control

Up to PostgreSQL 10 it was not possible to create procedures in PostgreSQL. Of course you can create functions which do not return anything but the possibility to create a procedure was not there. That will probably change in PostgreSQL(…)

Finally you will be able to use exit and quit in psql

When giving the PostgreSQL DBA Essentials workshop one of the main issues people have is how they can exit psql. Even on stackoverflow this is a popular topic. The good news(…)

Parallel pg_dump is slow by default?

Short answer: Yes, it is. Being at a customer the last days we wanted to parallel pg_dump a 2TB database. We were quite surprised that it was quite slow and it was not immediately clear why it was. Well, the(…)