Speaker Interview with Victor Yegorov
- nbtree-indexes in PostgreSQL. Useful novelties.
- Wednesday 14:40
- Could you briefly introduce yourself?
My name is Victor Yegorov. I work as PostgreSQL DBA for the DataEgret company.
I first met PostgreSQL back in 1998, at the time I was developer. Later I focused on administrative tasks, mostly around databases.
Primary database is PostgreSQL (of course), primary OS is Linux.
- How do you engage with the PostgreSQL Community?
- I follow PostgreSQL mailing lists, answer questions time to time. I’ve sent small patches for the yum repository. My engagement level is quite low, though, as I lost my C skills in recent years.
- Have you enjoyed previous pgconf.eu or FOSDEM conferences, either as an attendee or as speaker?
- I’ve visited PGConf.EU conferences in Warsaw and Tallinn previously. Great event to meet people, got to know about new stuff and PostgreSQL internals. For me visiting PGConf.EU is mostly about meeting old and making new friends.
- What will your talk be about, exactly? Why this topic?
I will speak about btree indexes, their internals and changes, that will come in this area in the about-to-be-released PostgreSQL 12. In my view, this is one of the most valuable features:
- btree indexes are most commonly used ones
- currently btree indexes under certain loads tend to accumulate bloat
- new changes will help keep indexes smaller (especially multicolumn ones)
- no configuration tuning required for this stuff, it just works
- What is the audience for your talk?
I will talk about btree index internals, but will not dig into code or low level data structures.
Therefore, everybody is welcome.
- What existing knowledge should the attendee have?
- Understanding of what btree indexes are and how they work is good, but not necessary.
- What is the one feature in PostgreSQL 12 which you like most?
- The one I will be speaking: nbtree indexes’ changes.
- Which other talk at this year's conference would you like to see?
As I have experience with GIS systems, I would like to hear about PostGIS (Paul Ramsey). 25 Interesting features of PostgreSQL 12 (Jobin Augustine) will give a good overview of the coming 12 version. (I will have to skip this talk though, as I cannot be in 2 rooms at once.)
Mostly I’m interested in low level stuff: IO subsystem (Andres Freund), Data Compression (Iwata Aya), Patroni (Alexander Kukushkin), Advantages of MVCC (Peter Geoghegan), PgBouncer (Peter Eisentraut).
And it’d be good to see how PostgreSQL compares with other systems, mostly ORACLE (as I have experience with it): Moving from Oracle to PostgreSQL (Hans-Jürgen Schönig) and Oracle DBA approach to troubleshoot PostgreSQL (Franck Pachot).
- Which measure, action, feature or activity would—in your eyes—help to accelerate the adoption of PostgreSQL?
Improved stats system, that provides extra information:
- timestamps of system object’s modifications
- information about query planning time, sent/received bytes, parallelism level
- list of transactions for a session, list of queries for a transaction
- locks and waited time for each lock
- historical view on the information above
I understand that such complex subsystem requires huge effort. Still, in my opinion, it is required, as currently PostgreSQL stats are updated after transaction completion, which makes it difficult to monitor OLAP systems.