reload

Database is reloaded from file if the file was modified since loaded.

update

As reload, but use incremental loading if possible. This allows for two processes to examine the same database file, where one writes the database and the other periodycally calls db_sync(update) to follow the modified data.

gc

Database was re-written, deleting all retractall statements. This is the same as gc(50).

gc(Percentage)

GC DB if the number of deleted terms is greater than the given percentage of the total number of terms.

gc(always)

GC DB without checking the percentage.

close

Database stream was closed

detach

Remove all registered persistency for the calling module

nop

No-operation performed

With unbound What, db_sync/1 reloads the database if it was modified on disk, gc it if it is dirty and close it if it is opened.