Method AddIndexes

Merges the provided indexes into this index.

After this completes, the index is optimized.

The provided IndexReaders are not closed.

NOTE: while this is running, any attempts to add or delete documents (with another thread) will be paused until this method completes.

See AddIndexesNoOptimize(Directory[]) for details on transactional semantics, temporary free space required in the Directory, and non-CFS segments on an Exception.

NOTE: if this method hits an OutOfMemoryError you should immediately close the writer. See above for details.