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Michael McCandless commented on LUCENE-2723: -------------------------------------------- bq. Should we keep MultiBulkPostingsEnum? I think we have to keep it. EG if someone makes a SlowMultiReaderWrapper and then run searches on it... bq. ParallelReader is one that can't currently? ParallelReader is a tricky one. If your ParallelReader only contains SegmentReaders (and eg you make a MultiReader on top), then everything's great, because ParallelReader dispatches by field to a unique SegmentReader. But if instead you make a ParallelReader whose child readers are themselves MultiReaders, then, yes it's basically the same as wrapping all of these subs in a SlowMultiReaderWrapper. > Speed up Lucene's low level bulk postings read API > -------------------------------------------------- > > Key: LUCENE-2723 > URL: https://issues.apache.org/jira/browse/LUCENE-2723 > Project: Lucene - Java > Issue Type: Improvement > Components: Index > Reporter: Michael McCandless > Assignee: Michael McCandless > Fix For: 4.0 > > Attachments: LUCENE-2723-termscorer.patch, > LUCENE-2723-termscorer.patch, LUCENE-2723-termscorer.patch, > LUCENE-2723.patch, LUCENE-2723.patch, LUCENE-2723.patch, LUCENE-2723.patch, > LUCENE-2723.patch, LUCENE-2723_bulkvint.patch, LUCENE-2723_facetPerSeg.patch, > LUCENE-2723_facetPerSeg.patch, LUCENE-2723_openEnum.patch, > LUCENE-2723_termscorer.patch, LUCENE-2723_wastedint.patch > > > Spinoff from LUCENE-1410. > The flex DocsEnum has a simple bulk-read API that reads the next chunk > of docs/freqs. But it's a poor fit for intblock codecs like FOR/PFOR > (from LUCENE-1410). This is not unlike sucking coffee through those > tiny plastic coffee stirrers they hand out airplanes that, > surprisingly, also happen to function as a straw. > As a result we see no perf gain from using FOR/PFOR. > I had hacked up a fix for this, described at in my blog post at > http://chbits.blogspot.com/2010/08/lucene-performance-with-pfordelta-codec.html > I'm opening this issue to get that work to a committable point. > So... I've worked out a new bulk-read API to address performance > bottleneck. It has some big changes over the current bulk-read API: > * You can now also bulk-read positions (but not payloads), but, I > have yet to cutover positional queries. > * The buffer contains doc deltas, not absolute values, for docIDs > and positions (freqs are absolute). > * Deleted docs are not filtered out. > * The doc & freq buffers need not be "aligned". For fixed intblock > codecs (FOR/PFOR) they will be, but for varint codecs (Simple9/16, > Group varint, etc.) they won't be. > It's still a work in progress... -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online. --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org For additional commands, e-mail: dev-h...@lucene.apache.org