lucene-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Michael McCandless (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (LUCENE-4283) Support more frequent skip with Block Postings Format
Date Wed, 08 Aug 2012 23:01:21 GMT

    [ https://issues.apache.org/jira/browse/LUCENE-4283?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13431486#comment-13431486
] 

Michael McCandless commented on LUCENE-4283:
--------------------------------------------

Thanks Billy, patch looks good... I also see some improvements in the skip
heavy queries:

{noformat}
                Task    QPS base StdDev base     QPS for  StdDev for      Pct diff
        HighSpanNear        1.70        0.05        1.66        0.02   -6% -    2%
            PKLookup      192.84        3.29      190.09        2.97   -4% -    1%
     MedSloppyPhrase        6.86        0.09        6.79        0.13   -4% -    2%
    HighSloppyPhrase        1.97        0.04        1.96        0.08   -6% -    5%
         MedSpanNear        4.88        0.12        4.85        0.06   -4% -    3%
           OrHighMed       23.40        0.74       23.31        0.73   -6% -    6%
     LowSloppyPhrase        7.58        0.12        7.56        0.18   -4% -    3%
           OrHighLow       27.00        0.92       26.93        0.86   -6% -    6%
            Wildcard       52.66        0.43       52.54        0.32   -1% -    1%
             Prefix3       82.44        0.90       82.36        0.87   -2% -    2%
              IntNRQ       11.61        0.02       11.60        0.02    0% -    0%
             LowTerm      513.72        0.95      513.40        2.77    0% -    0%
          OrHighHigh       11.27        0.35       11.27        0.35   -6% -    6%
            HighTerm       36.10        0.07       36.10        0.03    0% -    0%
             MedTerm      198.76        0.26      198.85        0.23    0% -    0%
             Respell       61.52        1.12       61.88        0.36   -1% -    3%
              Fuzzy1       74.60        1.37       75.07        0.58   -1% -    3%
              Fuzzy2       62.36        1.33       63.09        0.33   -1% -    3%
         AndHighHigh       23.62        0.08       24.07        0.21    0% -    3%
         LowSpanNear        9.65        0.22        9.88        0.06    0% -    5%
           LowPhrase       22.08        0.37       22.63        0.31    0% -    5%
          HighPhrase        1.77        0.10        1.83        0.09   -6% -   14%
           MedPhrase       13.09        0.29       13.54        0.25    0% -    7%
          AndHighLow      662.00        1.45      700.98       24.76    1% -    9%
          AndHighMed       69.58        0.18       75.15        1.28    5% -   10%
{noformat}

                
> Support more frequent skip with Block Postings Format
> -----------------------------------------------------
>
>                 Key: LUCENE-4283
>                 URL: https://issues.apache.org/jira/browse/LUCENE-4283
>             Project: Lucene - Core
>          Issue Type: Improvement
>            Reporter: Han Jiang
>            Priority: Minor
>         Attachments: LUCENE-4283-buggy.patch, LUCENE-4283-buggy.patch, LUCENE-4283-codes-cleanup.patch,
LUCENE-4283-record-next-skip.patch, LUCENE-4283-record-skip&inlining-scanning.patch, LUCENE-4283-slow.patch,
LUCENE-4283-small-interval-fully.patch, LUCENE-4283-small-interval-partially.patch
>
>
> This change works on the new bulk branch.
> Currently, our BlockPostingsFormat only supports skipInterval==blockSize. Every time
the skipper reaches the last level 0 skip point, we'll have to decode a whole block to read
doc/freq data. Also,  a higher level skip list will be created only for those df>blockSize^k,
which means for most terms, skipping will just be a linear scan. If we increase current blockSize
for better bulk i/o performance, current skip setting will be a bottleneck. 
> For ForPF, the encoded block can be easily splitted if we set skipInterval=32*k. 

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira

        

---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@lucene.apache.org
For additional commands, e-mail: dev-help@lucene.apache.org


Mime
View raw message