In the rare case where the index becomes corrupted (which can
signal itself by weird search results or crashes), the index files
need to be erased before restarting a clean indexing pass. Just delete
the xapiandb directory (see
next section), or,
alternatively, start the next recollindex with the
-z option, which will reset the database before
indexing. The difference between the two methods is that the
second will not change the current index format, which may be
undesirable if a newer format is supported by the Xapian
version.
