With ConcurrentMergeScheduler, adding all indexes at once to a single IndexWriter will use multiple threads to do the merging, assuming you have enough total segments that need merging (> 2 X mergeFactor will use 2 threads; > 3 X mergeFactor will use 3, etc.; CMS defaults to max 3 merge threads at once).
I think merging is mainly IO bound, so you may only see a win using multiple threads if your IO system has concurrency to exploit.
Try both and post back the results :) Mike Glen Newton wrote:
Let's say I have 8 indexes on a 4 core system and I want to merge them (inside a single vm instance). Is it better to do a single merge of all 8, or to in parallel threads merge in pairs, until there is only a single index left? I guess the question involves how multi-threaded merging is and if it will take advantage of all cores. thanks, -glen -- - --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
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