How does one create the incremental index?
One method is by using the -N switch to pass a file path to Swish-e when indexing. It will only index files that have a last modification date newer than the file supplied with the -N switch. This option has the disadvantage that Swish-e must process every file in every directory as if they were going to be indexed (the test for -N is done last right before indexing of the file contents begin and after all other tests on the file have been completed) — all that just to find a few new files. Also, if you use the Swish-e index file as the file passed to -N there may be files that were added after indexing was started, but before the index file was written. This could result in a file not being added to the index. Another option is to maintain a parallel directory tree that contains symlinks pointing to the main files. When a new file is added (or changed) to the main directory tree you create a symlink to the real file in the parallel directory tree. Then just index the symlink director
