Re: [HACKERS] Insert values() per-statement overhead

Andres>I think the biggestoverhead here is that the executor startup
includes
Andres>too many indirect (linked lists) datastructured, that allocated each
Andres>round

The case is very common: batch inserts are popular in Java, and ORMs use
batch API automatically.
However, there's high per-backend-message overhead, and that overhead is
very noticeable.

What is the approach to handle this?

Folding multiple DML statements into one with a help of CTE does not work
either (see https://github.com/pgjdbc/pgjdbc/issues/1165 ):

CTE doc>Trying to update the same row twice in a single statement is not
supported. Only one of the modifications takes place, but it is not easy
(and sometimes not possible) to reliably predict which one

Vladimir