Previously, I wrote that you should never lock tables. And you usually shouldn’t! But sometimes, there’s a good reason to. Here’s one.

When you are doing a schema-modifying operation, like adding a column to a table, PostgreSQL needs to take an ACCESS EXCLUSIVE lock on the table while it is modifying the system catalogs. Unless it needs to

In PostgreSQL, NUMERIC is a variable length type of fixed precision. You can have as many digits as you want (and you want to pay the storage for). DOUBLE PRECISION is a floating point type, with variable precision.

Sometimes, the question comes up: How much slower is NUMERIC than DOUBLE PRECISION, anyway?

Here’s a quick, highly unscientific

If you have something interesting to day about PostgreSQL, we [would love to get a proposal from you]. Even if you have never spoken before, consider responding to the CfP! PgDay 2020 is particularly friendly to first-time and inexperienced speakers. You’re among friends! If you use PostgreSQL, you almost certainly have opinions and experiences that others would love to hear

The very first PgDay San Francisco is coming to the Swedish-American Hall on January 21, 2020. It’s going to be an amazing event.

If you have something to say about PostgreSQL…

… the Call for Proposals is now open through November 22, 2019. We are looking for 40 minute talks about anything related to PostgreSQL. First-time speakers are

The slides from my presentation at PGDay Nordic 2019 are now available.

A feature of PostgreSQL that most people don’t even know exists is the ability to export and import transaction snapshots.

The documentation is accurate, but it doesn’t really describe why one might want to do such a thing.

First, what is a “snapshot”? You can think of a snapshot as the current set of committed tuples in the

PostgreSQL has two autovacuum-age related settings, autovacuum_freeze_max_age, and vacuum_freeze_table_age.

Both of them are in terms of the transaction “age” of a table: That is, how long it has been since the table has been scanned completely for “old” tuples that can be marked as “frozen” (a “frozen” tuple is one that no open transaction can cause to

The slides for my talk, “Breaking PostgreSQL at Scale” at FOSDEM 2019 are available.

Upon occasion, you want to get the current value of all the sequences in the database. For example, you may have fields that are integer rather than bigint, and you’re concerned how close you are to overflowing one of them (since sequences are bigint and will happily crash through the size of a 32-bit integer).

Unfortunately, currval()

The slides from my presentation, Securing PostgreSQL at PDXPUG PostgreSQL Day 2018 are now available.