What happens between end of explain analyze and end of query execution ?

Hi,

I have query that should be quick, and used to be quick, but is not
anymore... Explain analyze can be seen here http://explain.depesz.com/s/cpV
but it is fundamentaly quick : Total runtime: 0.545 ms.

But query execution takes 3.6 seconds. Only 12 rows are returned. Adding
a limit 1 has no influence.

Postgresql client and server are on the same server, on localhost.

I wonder where my 3.5 seconds are going....

Notice that there is no fancy configuration to tell Postgresql to
evaluate every query plan on earth, that is gecoxxxx settings are on
their default values.

Any idea on what can be happening that takes so long ?

Franck