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Sean Bridges commented on LUCENE-3932: -------------------------------------- {quote}Seems like if we made a direct "decode tii file and write in-memory format" (instead of going through SegmentTermEnum), we could get some of this back. The vLongs unfortunately need to be decoded/re-encoded because they are deltas in the file but absolutes in memory. But, eg the vInt docFreq could be a "copyVInt" method instead of readVInt then writeVInt, which should save a bit.{quote} Is the space savings of delta encoding worth the processing time? You could write the .tii file to disk such that on open you could read it straight into a byte[] > Improve load time of .tii files > ------------------------------- > > Key: LUCENE-3932 > URL: https://issues.apache.org/jira/browse/LUCENE-3932 > Project: Lucene - Java > Issue Type: Improvement > Affects Versions: 3.5 > Environment: Linux > Reporter: Sean Bridges > Attachments: LUCENE-3932.trunk.patch, perf.csv > > > We have a large 50 gig index which is optimized as one segment, with a 66 MEG > .tii file. This index has no norms, and no field cache. > It takes about 5 seconds to load this index, profiling reveals that 60% of > the time is spent in GrowableWriter.set(index, value), and most of time in > set(...) is spent resizing PackedInts.Mutatable current. > In the constructor for TermInfosReaderIndex, you initialize the writer with > the line, > {quote}GrowableWriter indexToTerms = new GrowableWriter(4, indexSize, > false);{quote} > For our index using four as the bit estimate results in 27 resizes. > The last value in indexToTerms is going to be ~ tiiFileLength, and if instead > you use, > {quote}int bitEstimate = (int) Math.ceil(Math.log10(tiiFileLength) / > Math.log10(2)); > GrowableWriter indexToTerms = new GrowableWriter(bitEstimate, indexSize, > false);{quote} > Load time improves to ~ 2 seconds. -- 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-unsubscr...@lucene.apache.org For additional commands, e-mail: dev-h...@lucene.apache.org