Occasionally a very long UPDATE transaction?

Question

PostgreSQL

Good afternoon! With a heavy load on the server, some requests are executed for a very long time (up to 20s). View request:

UPDATE "table" SET
      "views"="views"+1
WHERE "sid"=:sid AND "pid"=:pid

Indexes stand both on sid and on pid
Because of what such behavior can be?
The table being updated is very small

Answer 1

You most likely did not tune your database. This is not MySQL that works out of the box, it needs to be configured.
https://wiki.postgresql.org/wiki/Tuning_Your_Postg...