How to delete outdated shpinx indexes/records?

Question

Sphinx

There is a mysql base, new directories are added to it with great frequency and old ones are deleted.
What needs to be done so that old values ​​​​are also deleted from sphinx, because "indexer --rotate index", adds new values ​​and updates the changed ones, but does not delete the old ones (this data is no longer in the mysql database).
There is only one index, and the data is added to it.

Answer 1

indexer --rotate index
does a complete reindexing, old data will not be there unless of course your index is not a delta index.