There can be multiple file name databases. Users can select which
databases locate searches using the LOCATE_PATH
environment variable or a command line option. The system
administrator can choose the file name of the default database, the
frequency with which the databases are updated, and the directories
for which they contain entries. File name databases are updated by
running the updatedb program, typically nightly.
In networked environments, it often makes sense to build a database at
the root of each filesystem, containing the entries for that
filesystem. updatedb is then run for each filesystem on the
fileserver where that filesystem is on a local disk, to prevent
thrashing the network.
See Invoking updatedb, for the description of the options to
updatedb. These options can be used to specify which
directories are indexed by each database file.
The default location for the locate database depends on how findutils is built, but the findutils installation accompanying this manual uses the default location /usr/local/var/locatedb.
If no database exists at /usr/local/var/locatedb but the user did not
specify where to look (by using ‘-d’ or setting
LOCATE_PATH), then locate will also check for a
“secure” database in /var/lib/slocate/slocate.db.