Alex, this issue you linked is about the terms dictionary of doc values. Trejkaz linked the correct issue which is about the terms dictionary of the inverted index.
It's interesting you're seeing so much time spent in readVInt on 8.5 since there is a single vint that is read for each block in "LowercaseAsciiCompression.decompress". Are these relative timings consistent over multiple runs? On Mon, Jul 27, 2020 at 5:57 AM Alex K <aklib...@gmail.com> wrote: > Hi, > > Also have a look here: > https://issues.apache.org/jira/plugins/servlet/mobile#issue/LUCENE-9378 > > Seems it might be related. > - Alex > > On Sun, Jul 26, 2020, 23:31 Trejkaz <trej...@trypticon.org> wrote: > > > Hi all. > > > > I've been tracking down slow seeking performance in TermsEnum after > > updating to Lucene 8.5.1. > > > > On 8.5.1: > > > > SegmentTermsEnum.seekExact: 33,829 ms (70.2%) (remaining time in our > > code) > > SegmentTermsEnumFrame.loadBlock: 29,104 ms (60.4%) > > CompressionAlgorithm$2.read: 25,789 ms (53.5%) > > LowercaseAsciiCompression.decompress: 25,789 ms (53.5%) > > DataInput.readVInt: 24,690 ms (51.2%) > > SegmentTermsEnumFrame.scanToTerm: 2,921 ms (6.1%) > > > > On 7.7.0 (previous version we were using): > > > > SegmentTermsEnum.seekExact: 5,897 ms (43.7%) (remaining time in our > > code) > > SegmentTermsEnumFrame.loadBlock: 3,499 ms (25.9%) > > BufferedIndexInput.readBytes: 1,500 ms (11.1%) > > DataInput.readVInt: 1,108 (8.2%) > > SegmentTermsEnumFrame.scanToTerm: 1,501 ms (11.1%) > > > > So on the surface it sort of looks like the new version spends less > > time scanning and much more time loading blocks to decompress? > > > > Looking for some clues to what might have changed here, and whether > > it's something we can avoid, but currently LUCENE-4702 looks like it > > may be related. > > > > TX > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org > > For additional commands, e-mail: java-user-h...@lucene.apache.org > > > > > -- Adrien
