Re: ERROR: Out of memory - when connecting to database

 > They clearly were: notice the reference to "Autovacuum context" in the
 > memory map.  I think you are right to suspect that auto-analyze was
 > getting blown out by the wide bytea columns.  Did you have any
 > expression indexes involving those columns?

Yes, there are two unique btree indexes:

(col1, col2, col3, md5(array_to_string(col_bytea_arr, ''::text)) where
col4 is not null

(col1, col2, col3, md5(array_to_string(col_bytea_arr, ''::text)) where
col4 is null

What is the cause of the out of memory then?

Thank you,

Kuba