according to our users with lots of archive tables, discovery overhead is very noticeable:
show table 'non-existing table' randomly times out in a database with thousands of archive tables.
<dreas> actually "show tables" is also very slow. MyISAM: 2961 rows in set (3.71 sec), ARCHIVE: 2954 rows in set (36.96 sec)
using a binary with disabled discovery in archive has solved these problems.