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From Apache Wiki <>
Subject [Lucene-java Wiki] Update of "ImproveSearchingSpeed" by MikeMcCandless
Date Fri, 27 Mar 2009 11:41:23 GMT
Dear Wiki user,

You have subscribed to a wiki page or wiki category on "Lucene-java Wiki" for change notification.

The following page has been changed by MikeMcCandless:

The comment on the change is:
Add suggestion to use readOnly IndexReader & NIOFSDirectory

   * '''Get faster hardware, especially a faster IO system.'''
   Flash-based Solid State Drives works very well for Lucene searches. As seek-times for SSD's
are about 100 times faster than traditional platter-based harddrives, the usual penalty for
seeking is virtually eliminated. This means that SSD-equipped machines need less RAM for file
caching and that searchers require less warm-up time before they respond quickly.
+  * '''Open the IndexReader with readOnly=true.'''
+  This makes a big difference when multiple threads are sharing the same reader, as it removes
certain sources of thread contention.
+  * '''On non-Windows platform, using NIOFSDirectory instead of FSDirectory.'''
+  This also removes sources of contention when accessing the underlying files. Unfortunately,
due to a longstanding bug on Windows in Sun's JRE (
-- feel particularly free to go vote for it), NIOFSDirectory gets poor performance on Windows.
   * '''Add RAM to your hardware and/or increase the heap size for the JVM.'''

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