SET extra_float_digits = 3 I'm using PostgreSQL 9.2 with my web application that has three servlets with three selects.

I turn on the log. 

When I send my first query: select * from "Nomi" limit 4

before it the log shows me this other line:

execute &lt;unnamed&gt;: SET extra_float_digits = 3


What is this command?
Looks like that is a default setting in postgresql 8.5 onwards to guarantee recovery of higher precisions floats..

http://archives.postgresql.org/pgsql-bugs/2009-09/msg00171.php