[Xapian-tickets] [Xapian] #426: Backends should write all base files, then flush all base files

[Xapian]

#426: Backends should write all base files, then flush all base files
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 Reporter:  olly           |       Owner:  olly     
     Type:  defect         |      Status:  new      
 Priority:  normal         |   Milestone:  1.2.x    
Component:  Backend-Brass  |     Version:  SVN trunk
 Severity:  normal         |    Keywords:           
Blockedby:                 |    Platform:  Mac OS X 
 Blocking:                 |  
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Comment(by olly):

 Note that you shouldn't extrapolate from the overhead on a "basic
 operation".

 The drive's writeback buffer is a fixed size, so the time to write out all
 the data from it to the disk platters is bounded, so the delay incurred by
 each commit by using F_FULLFSYNC is likely to be at most a few seconds
 even if you're adding a million documents to the database in that commit.

 So the overhead of the F_FULLFSYNC is going to be proportionally much
 worse for a "basic operation" (changing a single tag and committing it)
 than when changes are batched up.  And
 batching up changes is recommended for other reasons if you want good
 indexing performance.

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Ticket URL: <http://trac.xapian.org/ticket/426#comment:6>
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