Catch all for Metadata storage in SQL database

Hi,

the

https://doc.dovecot.org/configuration_manual/imap_metadata/

sample uses

mail_attribute_dict = file:%h/Maildir/dovecot-attributes

which stores all keys=value pairs in the file.

http://dovecot.2317879.n4.nabble.com/Dovecot-v2-3-9-3-HTTP-API-Endpoint-for-...

uses a SQL dict, however very specific ones. How can I use a SQL dict to store _all_ keys, as with a file based storage?

I cannot find a documentation for "pattern" specification, that works as "catch all", in order to store anything not catched by patterns into the database.

https://wiki.dovecot.org/Dictionary does not give any hint (in my eyes).

-- Steffen Kaiser