[LUCENE-2650] improve windows defaults in FSDirectory

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.0-ALPHA
• Fix Version/s: 3.1, 4.0-ALPHA
• Component/s: core/store
• Lucene Fields: New
• Assignee: Robert Muir
• Reporter: Robert Muir
• Created: 17/Sep/10 17:52
• Updated: 30/Mar/11 15:50
• Resolved: 08/Dec/10 20:43

Description

Currently windows defaults to SimpleFSDirectory, but this is a problem due to the synchronization.

I have been benchmarking queries sequentially and was pretty surprised at how much faster
MMapDirectory is, for example for cases that do many seeks.

I think we should change the defaults for windows as such:

if (WINDOWS and UNMAP_SUPPORTED and 64-bit)
use MMapDirectory
else
use SimpleFSDirectory

I think we should just consider doing this for 4.0 only and see how it goes.

Issue Links

• relates to: LUCENE-2651 Add support for MMapDirectory's unmap in Apache Harmony