The ptrans file

ptrans specifies query-time path translations. These can be useful in multiple cases.

The file has a section for any index which needs translations, either the main one or additional query indexes. The sections are named with the Xapian index directory names. No slash character should exist at the end of the paths (all comparisons are textual). An example should make things sufficiently clear

          /this/directory/moved = /to/this/place

          /server/volume1/docdir = /net/server/volume1/docdir
          /server/volume2/docdir = /net/server/volume2/docdir