PGConf.Russia 2022

A book. Typically a reader sees only the final product, printed on paper or opened on a computer screen. In this talk I invite you to take a look at the dark side of my recently published “PostgreSQL Internals” book. Come if you are curious why the author would want to write scripts, modify the PostgreSQL source code, and program pictures.

I am going to explain a sorting method added in Postgres 14 that allows to create GiST index much faster. We'll also talk about the disadvantages of this sorting method discovered during implementation of its support in PostGIS and how it will be improved in the future. Also, new features and improvements included in PostGIS 3.2 will be reviewed.

We'll talk about the ways to change the database records without updates. To do this, we'll explore what's going on at the lowest level and see what can happen if we make changes in data files in different operation modes.

Every DBMS stores its data on a hard disc, so you may face a situation when your data on disc gets corrupted. This can happen due to a controller failure, logical or physical data corruption; there are also other reasons. If it is just the index file that gets corrupted, the index recreation command will enable you to restore data consistency in your DBMS. If a table file or a file of a system section gets corrupted, data restore is impossible. In this case, you need to invent workarounds. You can try to restore this data from backup files, copy it from the corrupted table, or find another way to solve this problem. In this talk, we'll tackle several cases of data corruption on disc and describe the options for restoring the data from the corrupted tables.