> On Nov 27, 2017, at 8:47 AM, Tomas Vondra <tomas.von...@2ndquadrant.com> > wrote: > > Hi, > > Attached is an updated version of the patch series, fixing the issues > reported by Mark Dilger: > > 1) Fix fabs() issue in histogram.c. > > 2) Do not rely on extra_data being StdAnalyzeData, and instead lookup > the LT operator explicitly. This also adds a simple regression tests to > make sure ANALYZE on arrays works fine, but perhaps we should invent > some simple queries too. > > 3) I've removed / clarified some of the comments mentioned by Mark. > > 4) I haven't changed how the statistics kinds are defined in relation.h, > but I agree there should be a comment explaining how STATS_EXT_INFO_* > relate to StatisticExtInfo.kinds. > > 5) The most significant change happened histograms. There used to be two > structures for histograms: > > - MVHistogram - expanded (no deduplication etc.), result of histogram > build and never used for estimation > > - MVSerializedHistogram - deduplicated to save space, produced from > MVHistogram before storing in pg_statistic_ext and never used for > estimation > > So there wasn't really any reason to expose the "non-serialized" version > outside histogram.c. It was just confusing and unnecessary, so I've > moved MVHistogram to histogram.c (and renamed it to MVHistogramBuild), > and renamed MVSerializedHistogram. And same for the MVBucket stuff. > > So now we only deal with MVHistogram everywhere, except in histogram.c. > > 6) I've also made MVHistogram to include a varlena header directly (and > be packed as a bytea), which allows us to store it without having to > call any serialization functions). > > I guess if we should do (5) and (6) for the MCV lists too, it seems more > convenient than the current approach. And perhaps even for the > statistics added to 9.6 (it does not change the storage format).
I tested your latest patches on my mac os x laptop and got one test failure due to the results of 'explain' coming up differently. For the record, I followed these steps: cd postgresql/ git pull # this got my directory up to 8526bcb2df76d5171b4f4d6dc7a97560a73a5eff with no local changes patch -p 1 < ../0001-multivariate-MCV-lists.patch patch -p 1 < ../0002-multivariate-histograms.patch ./configure --prefix=/Users/mark/master/testinstall --enable-cassert --enable-tap-tests --enable-depend && make -j4 && make check-world mark
regression.diffs
Description: Binary data
stats_ext.out
Description: Binary data
