The Xapian search engine supports searching from multiple databases at once, creating a tiered database structure. To use Xapian, these tiers must be defined in :cyrusman:`imapd.conf(5)` with the defaultsearchtier and searchpartition-name settings.
Specify the name of the default search tier using the defaultsearchtier setting:
Each search tier to be used requires a partition location be specified via a searchpartition-name setting, wherein "name" is replaced with the name of the mail spool for which this search partition is to be used, and prepended by the name of the tier with which it is associated:
{tier}searchpartition-{spool}
Again, building on our examples from :ref:`imap-admin-locations-spool`, here we have three spool partitions defined, so we need three search partitions for each tier. In this example, with just a single tier, we will be adding three search partitions.
Sample:
defaultpartition: main partition-main: /var/spool/cyrus partition-am: /var/spool/cyrus-am partition-nz: /var/spool/cyrus-nz partition-shared: /var/spool/cyrus-shared metapartition_files: header index cache expunge squat annotations metapartition-main: /var/spool/cyrusmeta/main metapartition-am: /var/spool/cyrusmeta/am metapartition-nz: /var/spool/cyrusmeta/nz metapartition-shared: /var/spool/cyrusmeta/shared search_engine: xapian search_index_headers: no search_batchsize: 8192 defaultsearchtier: temp tempsearchpartition-main: /var/spool/search/main tempsearchpartition-am: /var/spool/search/am tempsearchpartition-nz: /var/spool/search/nz tempsearchpartition-shared: /var/spool/search/shared
These settings are in :cyrusman:`imapd.conf(5)`: