A (2011-04-25): Switched from a traditional spinning-magnets hard drive (Western Digital Caviar Green, 1TB) to a 240 GB OCZ Vertex III SSD; this change gave a small increase in indexing rate, drastically reduced variance on the NRT reopen time (NRT is IO intensive), and didn't affect query performance (which is expected since the postings are small enough to fit into the OS's IO cache.

B (2011-05-02): Concurrent flushing, a major improvement to Lucene, was committed. Before this change, flushing a segment in IndexWriter was single-threaded and blocked all other indexing threads; after this change, each indexing thread flushes its own segment without blocking indexing of other threads. On highly concurrent hardware (the machine running these tests has 24 cores) this can result in a tremendous increase in Lucene's indexing throughput. See this post for details.

Some queries did get slower, because the index now has more segments. Unfortunately, the index produced by concurrent flushing will vary, night to night, in how many segments it contains, so this is a further source of noise in the search results.

C (2011-05-06): Changed how I build the index used for searching, to only use one thread. This results in exactly the same index structure (same segments, same docs per segment) from night to night, to avoid the added noise from change B.

D (2011-05-07): Increased number of indexing threads from 6 to 20 and dropped the IndexWriter RAM buffer from 512 MB to 350 MB. See this post for details.

E (2011-05-11): Added TermQuery, sorting by date/time and title fields.

F (2011-05-14): Added TermQuery, grouping by fields with 100, 10K, 1M unique values.

G (2011-06-03): Added Term (bgroup) and Term (bgroup, 1pass) using the BlockGroupingCollector for grouping into 1M unique groups.

H (2011-06-26): Switched to MemoryCodec for the primary-key 'id' field so that lookups (either for PKLookup test or for deletions during reopen in the NRT test) are fast, with no IO. Also switched to NRTCachingDirectory for the NRT test, so that small new segments are written only in RAM.

I (2011-07-04): Switched from Java 1.6.0_21 to 1.6.0_26

J (2011-07-11): LUCENE-3233: fast SynonymFilter using an FST, including an optimization to the FST representation allowing array arcs even when some arcs have large outputs; this resulted in a good speedup for MemoryCodec, which also speeds up the primary key lookup performance.

K (2011-07-22): LUCENE-3328: If all clauses of a BooleanQuery are MUST and are TermQuery then create a specialized scorer for scoring this common case.

L (2011-07-30): Switched back to Java 1.6.0_21 from 1.6.0_26 because _26 would sometimes deadlock threads.

M (2011-08-20): LUCENE-3030: cutover to more efficient BlockTree terms dict.

N (2011-09-22): LUCENE-3215: more efficient scoring for sloppy PhraseQuery.

O (2011-11-30): LUCENE-3584: make postings bulk API codec-private

P (2011-12-07): Switched to Java 1.7.0_01

Q (2011-12-16): LUCENE-3648: JIT optimizations to Lucene40 DocsEnum

R (2012-01-30): LUCENE-2858: Split IndexReader in AtomicReader and CompositeReader

S (2012-03-18): LUCENE-3738: Be consistent about negative vInt/vLong

V (2012-05-06): LUCENE-4024: FuzzyQuery never does edit distance > 2

W (2012-05-15): LUCENE-4024: (rev 1338668) fixed ob1 bug causing FuzzyQ(1) to be TermQuery

T (2012-05-25): LUCENE-4062: new aligned packed-bits implementations

U (2012-05-28): Disable Java's compressed OOPS (-XX:-UseCompressedOops), and LUCENE-4055: refactor SegmentInfos/FieldInfos

X (2012-06-02): Re-enable Java's compressed OOPS

Y (2012-06-06): Switched to Java 1.7.0_04

Z (2012-06-26): Fixed silly performance bug in PKLookupTask.java

AA (2012-10-06): Stopped overclocking the computer running benchmarks.

AB (2012-10-15): LUCENE-4446: switch to BlockPostingsFormat

AC (2012-12-10): LUCENE-4598: small optimizations to facet aggregation

AD (2013-01-11): LUCENE-4620: IntEncoder/Decoder bulk API

AE (2013-01-17): Facet performance improvements: LUCENE-4686, LUCENE-4620, LUCENE-4602

AE (2013-01-17): Facet performance improvements: LUCENE-4686, LUCENE-4620, LUCENE-4602

AF (2013-01-21): Facet performance improvements: LUCENE-4600

AF (2013-01-21): Facet performance improvements: LUCENE-4600

AG (2013-01-24): Switched to NO_PARENTS faceting

AH (2013-02-07): DocValues improvements (LUCENE-4547) and facets API improvements (LUCENE-4757)

AI (2013-02-12): LUCENE-4764: new Facet42DocValuesFormat for faster but more RAM-consuming DocValues

AI (2013-02-12): LUCENE-4764: new Facet42DocValuesFormat for faster but more RAM-consuming DocValues

AJ (2013-02-22): LUCENE-4791: optimize ConjunctionTermScorer to use skipping on first term

AK (2013-03-14): LUCENE-4607: add DISI/Spans.cost

AL (2013-05-03): LUCENE-4946: SorterTemplate

AM (2013-06-20): LUCENE-5063: compress int and long FieldCache entries

AN (2013-07-31): LUCENE-5140: recover slowdown in span queries and exact phrase query

AO (2013-09-10): Switched to Java 1.7.0_40

AP (2013-11-09): Switched to DirectDocValuesFormat for the Date facets field.

AP (2013-11-09): Switched to DirectDocValuesFormat for the Date facets field.

AQ (2014-02-06): LUCENE-5425: performance improvement for FixedBitSet.iterator

AW (2014-03-11): LUCENE-5487: add BulkScorer

AR (2014-04-05): LUCENE-527: LeafCollector (made CachingCollector slower)

AS (2014-04-25): Upgraded to Ubuntu 14.04 LTS (kernel 3.13.0-32-generic #57)

AT (2014-06-10): Switched from DirectDVFormat to Lucene's default for Date facet field

AU (2014-07-25): Disabled transparent huge pages

AU (2014-07-25): Disabled transparent huge pages

AV (2014-08-30): Re-enabled transparent huge pages

AV (2014-08-30): Re-enabled transparent huge pages

AX (2014-11-01): LUCENE-6030: norms compression

AX (2014-11-01): LUCENE-6030: norms compression

AY (2014-11-22): Upgrade from java 1.7.0_55-b13 to java 1.8.0_20-ea-b05

AZ (2015-01-15): LUCENE-6179: remove out-of-order scoring

BA (2015-01-19): LUCENE-6184: BooleanScorer better deals with sparse clauses

BB (2015-02-13): LUCENE-6198: Two phase intersection (approximations are not needed by any query in this benchmark, but the change refactored ConjunctionScorer a bit)

BD (2015-03-02): LUCENE-6320: Speed up CheckIndex

BE (2015-03-06): Upgrade JDK from 1.8.0_25-b17 to 1.8.0_40-b25

BF (2015-04-02): LUCENE-6308: span queries support two-phased iteration

BG (2015-04-04): LUCENE-5879: add auto-prefix terms

BH (2015-06-24): LUCENE-6548: some optimizations to block tree intersect

BH (2015-06-24): LUCENE-6548: some optimizations to block tree intersect

BI (2015-09-15): LUCENE-6789 switch to BM25 scoring by default

BJ (2015-10-05): Randomize what time of day benchmark runs

BJ (2015-10-05): Randomize what time of day benchmark runs

BK (2015-12-02): Upgrade to beast2 (72 cores, 256 GB RAM)

BL (2015-12-10): LUCENE-6919: Change the Scorer API to expose an iterator instead of extending DocIdSetIterator

BM (2015-12-14): LUCENE-6917: Change from LegacyNumericRangeQuery to DimensionalRangeQuery

BN (2016-05-23): Fix silly benchmark bottlenecks and re-tune for high indexing throughput

BN (2016-05-23): Fix silly benchmark bottlenecks and re-tune for high indexing throughput

BO (2016-05-25): Fix another benchmark bottleneck for 1 KB docs (but this added a bug in TermDateFacets, fixed on 10/18)

BO (2016-05-25): Fix another benchmark bottleneck for 1 KB docs (but this added a bug in TermDateFacets, fixed on 10/18)

BP (2016-06-13): LUCENE-7330: Speed up conjunctions

BR (2016-07-16): Upgrade beast2 kernel from 4.4.x to 4.6.x

BS (2016-08-17): Upgrade beast2 kernel from 4.6.x to 4.7.0

BT (2016-09-04): Upgrade beast2 kernel from 4.7.0 to 4.7.2

BU (2016-09-21): LUCENE-7407: Change doc values from random access to iterator API

BV (2016-10-18): Fix silly TermDateFacets bug causing single date facet to be indexed for all docs, added on 5/25

BW (2016-10-24): LUCENE-7462: give doc values an advanceExact API

BW (2016-10-24): LUCENE-7462: give doc values an advanceExact API

BX (2016-10-26): LUCENE-7519: optimize computing browse-only facets, LUCENE-7489: Remove one layer of abstraction in binary doc values and single-valued numerics

BX (2016-10-26): LUCENE-7519: optimize computing browse-only facets, LUCENE-7489: Remove one layer of abstraction in binary doc values and single-valued numerics

BY (2016-10-27): Re-enable transparent huge pages in Linux

BY (2016-10-27): Re-enable transparent huge pages in Linux

BZ (2016-10-31): LUCENE-7135: This issue accidentally caused FSDirectory.open to use NIOFSDirectory instead of MMapDirectory for e.g. CheckIndex

CA (2016-11-02): LUCENE-7135: Fixed this issue so we use MMapDirectory again

CB (2017-01-18): LUCENE-7641: Speed up point ranges that match most documents

CC (2017-10-27): LUCENE-7997: BM25 to use doubles instead of floats

CC (2017-10-27): LUCENE-7997: BM25 to use doubles instead of floats

CD (2018-01-31): LUCENE-4198: Allow codecs to index term impacts

CE (2018-02-20): LUCENE-8153: CheckIndex spends less time checking impacts

CF (2018-05-02): LUCENE-8279: CheckIndex now cross-checks terms with norms

CG (2018-05-11): Primary key now indexed with the default codec instead of the specialized Memory postings format

CG (2018-05-11): Primary key now indexed with the default codec instead of the specialized Memory postings format

CH (2018-05-25): LUCENE-8312: Leverage impacts for SynonymQuery (introduced regression for non-scoring term queries)

CI (2018-08-07): LUCENE-8312: Fixed regression with non-scoring term queries

CJ (2018-08-07): LUCENE-8060: Stop counting total hits by default

CI (2018-08-07): LUCENE-8312: Fixed regression with non-scoring term queries

CJ (2018-08-07): LUCENE-8060: Stop counting total hits by default

CK (2018-08-18): LUCENE-8448: Propagate min competitive score to sub clauses

CL (2018-11-19): LUCENE-8464: ConstantScoreScorer now implements setMinCompetitiveScore

CM (2019-04-23): Switched to OpenJDK 11

CM (2019-04-23): Switched to OpenJDK 11

CM (2019-04-23): Switched to OpenJDK 11

CN (2019-04-30): Switched GC back to ParallelGC (away from default G1GC)

CN (2019-04-30): Switched GC back to ParallelGC (away from default G1GC)

CO (2019-05-06): LUCENE-8781: FST lookup performance has been improved in many cases by encoding Arcs using full-sized arrays with gaps

CP (2019-05-24): LUCENE-8770: Two-phase support in conjunctions

CQ (2019-07-02): LUCENE-8901: Load freq blocks lazily

CR (2019-07-09): LUCENE-8311: Compute impacts for phrase queries

CS (2019-09-26): LUCENE-8980: Blocktree seekExact now checks min-max range of the segment

CT (2019-10-14): LUCENE-8920: Disable direct addressing of arcs.

CU (2019-11-14): LUCENE-8920: Re-enable direct addressing of arcs.

CV (2019-11-19): LUCENE-9027: SIMD decompression of postings.

CW (2019-11-21): LUCENE-9056: Fewer conditionals in #nextDoc/#advance

CX (2020-01-13): Switch to OpenJDK 13

CX (2020-01-13): Switch to OpenJDK 13

CY (2020-01-14): Switch to OpenJDK 12

CY (2020-01-14): Switch to OpenJDK 12

CZ (2020-01-17): Move invariant checks of CompetitiveImpactAccumulator under an assert

DA (2020-01-24): LUCENE-4702: compress suffix bytes in terms dictionary

DA (2020-01-24): LUCENE-4702: compress suffix bytes in terms dictionary

DB (2020-02-18): LUCENE-9211: Adding compression to BinaryDocValues storage

DC (2020-09-09): LUCENE-9511: Include StoredFieldsWriter in DWPT accounting

DC (2020-09-09): LUCENE-9511: Include StoredFieldsWriter in DWPT accounting

DD (2020-10-27): LUCENE-9280: optimization to skip non-competitive documents when sorting by field by indexing benchmark datetime field as both points and doc values

DD (2020-10-27): LUCENE-9280: optimization to skip non-competitive documents when sorting by field by indexing benchmark datetime field as both points and doc values

DE (2020-11-06): Move to new beast 3 Ryzen Threadripper 3990X hardware for all nightly benchmarks: 64 cores (128 with hyperthreading), 256 GB RAM, 960 GB Intel 905P Optane, Linux 5.9.2-arch1-1, still OpenJDK 12.0.2+10

DF (2020-11-14): LUCENE-9378: Configurable compression for binary doc values

DG (2020-12-04): Switch to JDK 15 (from JDK 12)

DH (2020-12-09 10:00:13): Add KNN vectors to indexing metrics

DI (2020-12-10): LUCENE-9626: switch to native arrays for HNSW ANN vector search

DJ (2020-12-28): LUCENE-9644: add diversity to HNSW (ANN search) neighbor selection, apparently yielding performance gains to VectorSearch task

DL (2021-01-07): LUCENE-9652: add dedicated method, DataInput.readLEFloats, to read float[] from DataInput, optimizing HNSW KNN

DK (2021-01-09 13:35:50): increase max number of concurrent merges from 3 to 12 for indexing tasks; increase Indexer heap from 8 to 32 GB

DM (2021-01-24 17:25:07): enable BinaryDocValues compression in taxonomy index

DN (2021-01-28): LUCENE-9695: WTF somehow this bug fix hurt vector indexing throughput?

DO (2021-02-25): Upgrade beast3 to Arch Linux 5.11.1

DP (2021-03-14 08:23:12): Move vectors indexing to dedicated (separate) indexing task

DQ (2021-06-24 00:03:16): LUCENE-9613: Create blocks for ords when it helps Lucene80DocValuesFormat

DR (2021-08-24 00:03:22): LUCENE-5309: specialize single-valued SortedSetDocValues faceting

DS (2021-08-26 07:26:00): LUCENE-10067: specialize SSDV ordinal decode

DT (2021-08-27 10:46:59): Upgrade to JDK 16.0.2+7

DU (2021-09-01 00:03:16): LUCENE-9662: CheckIndex should be concurrent

DV (2021-09-03 00:03:25): Use 16 concurrent threads for CheckIndex

DW (2021-09-25 00:03:25): LUCENE-10109: Increase default beam width from 16 to 100

DX (2021-10-05 12:21:08): Upgrade Linux kernel from 5.13.12 to 5.14.8

DY (2021-10-19 08:14:33): Upgrade to JDK17+35, and pass -release to ecj linting

EA (2021-11-24 18:04:23): LUCENE-10062: switch to storing taxonomy Facet ordinals from custom encoding in BINARY DV field, to SSDV field

EC (2022-01-03 18:03:13): LUCENE-10346: specialize single-valued doc values during taxonomy facet counting

ED (2022-01-19 10:17:11): Upgrade arch linux 5.15.10 -> 5.16.1; LUCENE-10375: Speed up HNSW merge by writing combined vector data

EE (2022-01-26 18:03:08): LUCENE-10054: Make HnswGraph hierarchical

EF (2022-02-18 07:54:59): LUCENE-10391: Reuse data structures across HnswGraph#searchLevel calls

EG (2022-02-18 07:54:59): LUCENE-10408 Better encoding of doc Ids in vectors

EH (2022-02-25 18:03:10): LUCENE-10421: Use fixed seed for HNSW search

EI (2022-03-23 18:03:07): LUCENE-10481: FacetsCollector sets ScoreMode.COMPLETE_NO_SCORES when scores are not needed

EJ (2022-04-21 18:03:04): LUCENE-10517: specialize SSDV pure-browse facets for some cases

EK (2022-05-12 18:02:51): LUCENE-10527: Use 2*maxConn for last layer in HNSW

EL (2022-05-19): GITHUB#11610: Prevent pathological O(N^2) merges

EM (2022-06-07 18:02:50): LUCENE-10078: Enable merge-on-refresh by default

EN (2022-07-04 18:02:46): LUCENE-10480: Use BMM scorer for 2 clauses disjunction

EO (2022-07-08 18:02:52): LUCENE-10480: Move scoring from advance to TwoPhaseIterator#matches

EP (2022-07-13 18:02:33): #1010: Specialize ordinal encoding for SortedSetDocValues

EQ (2022-07-23 06:00:31): LUCENE-10592: Build HNSW graph during indexing

ER (2022-07-30 18:02:50): LUCENE-10633: Dynamic pruning for queries sorted by SORTED(_SET) field

ES (2022-08-10): GITHUB#1017: Add new ShapeDocValuesField for LatLonShape and XYShape

ET (2022-09-28): GITHUB#11824: recover performance regression of LatLonPoint#newPolygonQuery

EU (2022-09-29): Update all Arch Linux packages, including kernel from 5.17.5 -> 5.19.12

EV (2022-09-30): Switch from OpenJDK 17.0.1+12 -> standard Arch Linux OpenJDK 17.0.4.1+1

EW (2022-10-06): luceneutil#192: increase the default topN from 10 to 100

EW (2022-10-06): luceneutil#192: increase the default topN from 10 to 100

EX (2022-10-19): Fix CombinedFieldsQuery tasks: https://github.com/mikemccand/luceneutil/commit/56729cf341a443fb81148dd25d3d49cb88bc72e8

EY (2022-10-26): Upgrade to OpenJDK 19.0.1+10

EZ (2022-11-03): Add --enable-preview command-line JVM flag to test new Panama-based MMapDirectory implementation

FA (2022-11-16): GITHUB#11939: fix bug of incorrect cost after upgradeToBitSet in DocIdSetBuilder class

FB (2023-03-01): GITHUB#12055: Better skipping for multi-term queries with a FILTER rewrite

FC (2023-03-14): GITHUB#12198: Reduced contention and increased thread affinity

FD (2023-04-04): Remove --enable-preview JVM flag

FE (2023-04-09): Upgrade Linux kernel 5.19.12 -> 6.2.9 plus all packages

FF (2023-04-11): Upgrade Java 19.0.2+7 to 20+36-2344

FG (2023-05-12): Allocate one NeighborQueue per search for results #12255

FH (2023-05-20): Revert allocate one NeighborQueue per search for results #12255

FI (2023-05-29): Use the incubating Panama API to accelerate KNN indexing and searching #12311

FJ (2023-06-22): Implement top-level disjunctions as a bulk scorer

FK (2023-07-20): Add BS1 optimization to MaxScoreBulkScorer; also increase vectors dimensions to 768: https://github.com/mikemccand/luceneutil/commit/ce6901ca05f3b944144e3a1e47e1efcc13a30e33

FK (2023-07-20): Add BS1 optimization to MaxScoreBulkScorer; also increase vectors dimensions to 768: https://github.com/mikemccand/luceneutil/commit/ce6901ca05f3b944144e3a1e47e1efcc13a30e33

FL (2023-07-28): Initialize facet counting data structures lazily (https://github.com/apache/lucene/commit/179b45bc23e4496278b7058811577b66ef3af77d); but this also incorrectly shifted which facet tasks are executed, making results incomparable: https://github.com/mikemccand/luceneutil/issues/226

FM (2023-08-03 06:31:03): Fix non-determinism in nightly benchmarks for vector and taxo facets tasks: https://github.com/mikemccand/luceneutil/issues/226, reduce overhead of BooleanScorer in non-scoring mode: https://github.com/apache/lucene/pull/12475, and reduce overhead of intersecting the scorer with the collector's competitive iterator: https://github.com/apache/lucene/pull/12481

FN (2023-08-11): Optimized counts on disjunctive queries https://github.com/apache/lucene/pull/12415

FO (2023-09-15): No longer propagate min competitive scores through the query tree https://github.com/apache/lucene/pull/12490

FP (2023-09-28): Specialized bulk scorer for conjunctions https://github.com/apache/lucene/pull/12382

FQ (2023-10-04): Reduced FST block size for BlockTreeTermsWriter https://github.com/apache/lucene/pull/12604

FR (2023-10-10): Better output prefix sharing in terms index https://github.com/apache/lucene/pull/12631

FS (2023-10-13): Lazy decoding of frequencies in BlockImpacstDocsEnum https://github.com/apache/lucene/pull/12668

FT (2023-10-17): Specialize BlockImpactsDocsEnum#nextDoc() https://github.com/apache/lucene/pull/12670

FU (2023-10-28): Intersect clauses in disjunctions when block max scores require multiple clauses to match https://github.com/apache/lucene/pull/12589

FU (2023-10-28): Intersect clauses in disjunctions when block max scores require multiple clauses to match https://github.com/apache/lucene/pull/12589

FV (2023-11-02): Add a specialized bulk scorer for regular conjunctions https://github.com/apache/lucene/pull/12719

FW (2023-11-09): Remove patching for doc blocks https://github.com/apache/lucene/pull/12741

FX (2023-11-13): Also index int8 quantized HNSW vectors, but introduced a bug where quantized usage is flipped, this is fixed on 2023-12-04

FY (2023-11-21): Switch tail postings to group-varint https://github.com/apache/lucene/pull/12782

FZ (2023-11-23): Skip decoding tail freqs when they are not needed https://github.com/apache/lucene/pull/12832

GA (2023-12-04): Correct int8 quantized vectors usage, this was flipped in the 2023-11-13 change and is now corrected

GB (2023-12-14): Change CheckIndex level back to 2 https://github.com/mikemccand/luceneutil/pull/251

GC (2023-12-24): Move group-varint encoding/decoding logic to DataOutput/DataInput https://github.com/apache/lucene/pull/12841

GD (2024-01-16): Override #readVInt and #readVLong for ByteBufferDataInput https://github.com/apache/lucene/pull/592

GE (2024-02-02): Optimize counts on two clause term disjunctions https://github.com/apache/lucene/pull/13036

GF (2024-02-07): Speedup concurrent multi-segment HNWS graph search by exchanging the global top scores collected so far across segments https://github.com/apache/lucene/pull/12962

GG (2024-03-01): Upgrade to OpenJDK 21

GH (2024-03-04): Upgrade from JDK 21+35 -> 21.0.2+13, and OS from 6.4.1-arch1-1 to 6.7.8-arch1-1

GI (2024-03-26): Break point estimation when threshold exceeded https://github.com/apache/lucene/pull/13199

GI (2024-03-26): Break point estimation when threshold exceeded https://github.com/apache/lucene/pull/13199

GJ (2024-04-01): #11888: optimize terms dictionary lookups when all terms have the same suffix length, which helps primary key lookup for fixed-length fields

GL (2024-04-30): #256: regenerate 768 dimension Cohere vectors to fix float64 -> float32 conversion bug https://github.com/mikemccand/luceneutil/issues/256

GM (2024-05-20): Disjunction as CompetitiveIterator for numeric dynamic pruning https://github.com/apache/lucene/pull/13221

GN (2024-06-24): Enable intra-query concurrency across 8 threads

GO (2024-07-05): TaskExecutor should not fork unnecessarily https://github.com/apache/lucene/pull/13472

GP (2024-07-08): Replace AtomicLong with LongAdder in HitsThresholdChecker https://github.com/apache/lucene/pull/13546

GQ (2024-07-19): Stop requiring MaxScoreBulkScorer's outer window from having at least INNER_WINDOW_SIZE docs https://github.com/apache/lucene/pull/13582

GR (2024-07-24): Further reduce the search concurrency overhead https://github.com/apache/lucene/pull/13606, Run search tasks in IndexSearcher's executor https://github.com/mikemccand/luceneutil/pull/286

GS (2024-07-25): Bump the window size of disjunctions from 2,048 to 4,096 https://github.com/apache/lucene/pull/13605

GT (2024-07-31): Move to 2 levels of skip data, inlined in postings lists https://github.com/apache/lucene/pull/13585

GU (2024-08-25): Switch to 768 dimension Cohere vectors (from MPNet 768 dimensions)

GV (2024-08-28): Speed up advancing within a block https://github.com/apache/lucene/pull/13692

GW (2024-09-16): Revert: Speed up advancing within a block https://github.com/apache/lucene/pull/13692

GX (2024-10-03): Speedup GlobalHitsThresholdChecker a little https://github.com/apache/lucene/pull/13836

GY (2024-10-07): Speedup MaxScoreCache.computeMaxScore https://github.com/apache/lucene/pull/13865

GZ (2024-10-09): Speedup OrderedIntervalsSource https://github.com/apache/lucene/pull/13871

HA (2024-10-12): Use RandomAccessInput instead of seeking in Lucene90DocValuesProducer https://github.com/apache/lucene/pull/13894 Lazy initialize ForDeltaUtil and ForUtil in Lucene912PostingsReader https://github.com/apache/lucene/pull/13885

HB (2024-10-14): Dry up EverythingEnum and BlockDocsEnum in Lucene912PostingsReader https://github.com/apache/lucene/pull/13901

HC (2024-10-21): Make BooleanScorer work on top of Scorers rather than BulkScorers https://github.com/apache/lucene/pull/13931, Speedup OrderIntervalsSource some more https://github.com/apache/lucene/pull/13937

HD (2024-10-22): Introduce a heuristic to amortize the per-window overhead in MaxScoreBulkScorer https://github.com/apache/lucene/pull/13941

HE (2024-10-26): Remove LeafSimScorer abstraction https://github.com/apache/lucene/pull/13957

HF (2024-10-28): Remove HitsThresholdChecker https://github.com/apache/lucene/pull/13943

HG (2024-10-30): Speed up advancing within a block https://github.com/apache/lucene/pull/13958

HH (2024-11-01): Move postings back to int[] to take advantage of having more lanes per vector https://github.com/apache/lucene/pull/13968

HI (2024-11-01): Make CombinedFieldQuery eligible for WAND/MAXSCORE. https://github.com/apache/lucene/pull/13999 Only consider clauses whose cost is less than the lead cost to compute block boundaries in WANDScorer. https://github.com/apache/lucene/pull/14003

HK (2024-11-22): Make CombinedFieldQuery eligible for WAND/MAXSCORE. https://github.com/apache/lucene/pull/13999 Only consider clauses whose cost is less than the lead cost to compute block boundaries in WANDScorer. https://github.com/apache/lucene/pull/14003

HL (2024-11-25): Stop using SlowImpactsEnum for terms whose docFreq is less than 128. https://github.com/apache/lucene/pull/14017

HM (2024-11-26): Make WANDScorer compute scores on the fly. https://github.com/apache/lucene/pull/14021

HN (2024-11-27): Run filtered disjunctions with MaxScoreBulkScorer. https://github.com/apache/lucene/pull/14014

HO (2024-11-29): Make inlining decisions a bit more predictable in our main queries https://github.com/apache/lucene/pull/14023

HP (2024-12-02): Speed up PostingsEnum when reading positions. https://github.com/apache/lucene/pull/14032

HR (2024-12-06): Introduce a BulkScorer for DisjunctionMaxQuery. https://github.com/apache/lucene/pull/14040

HS (2024-12-17): Speed up advancing on the disjunction iterator https://github.com/apache/lucene/pull/14052

HT (2024-12-18): Let DocIdSetIterator optimize loading into a FixedBitSet https://github.com/apache/lucene/pull/14069

HU (2024-12-19): Use the new loadIntoBitSet API to speed up dense conjunctions https://github.com/apache/lucene/pull/14080

HV (2024-12-20): Add JVM command-line options -XX:+UnlockDiagnosticVMOptions -XX:+DebugNonSafepoints -XX:+PreserveFramePointer so Linux perf command can see all C function calls

HW (2024-12-26): Optimize BitSetIterator#intoBitSet https://github.com/apache/lucene/pull/14083

HX (2025-01-09): Remove JVM command-line options -XX:+UnlockDiagnosticVMOptions -XX:+DebugNonSafepoints -XX:+PreserveFramePointer

HY (2025-01-14): Encode dense blocks of postings as bit sets. https://github.com/apache/lucene/pull/14133

HZ (2025-01-23): Add a bias towards bit set encoding. https://github.com/apache/lucene/pull/14155

IA (2025-01-25): Not maintain docBufferUpTo when only docs needed. https://github.com/apache/lucene/pull/14164

IB (2025-02-09): Reduce virtual calls when visiting bpv24-encoded doc ids in BKD leaves. https://github.com/apache/lucene/pull/14176

IC (2025-02-13): Change the filtered HNSW search algorithm to one based on ACORN-1. https://github.com/apache/lucene/pull/14160

ID (2025-02-27): Use DenseConjunctionBulkScorer for single queries sometimes. https://github.com/apache/lucene/pull/14293

IE (2025-03-13): Speed up scoring conjunctions a bit. https://github.com/apache/lucene/pull/14345

IF (2025-03-16): Decode doc ids in BKD leaves with auto-vectorized loops. https://github.com/apache/lucene/pull/14203

IG (2025-03-20): Implement bulk adding methods for dynamic pruning. https://github.com/apache/lucene/pull/14365

IH (2025-04-14): A specialized Trie for Block Tree Index. https://github.com/apache/lucene/pull/14333

IJ (2025-05-01): Kernel upgrade from 6.12.4 -> 6.14.4, which including changing HZ (how many time slices per sec the Linux scheduler creates) from 300 (Arch Linux) to 1000, likely the cause of our slowdown

IK (2025-05-13): Regression from optimistic KNN query -- see https://github.com/apache/lucene/issues/14671

IL (2025-05-15): Downgraded from Java 24 to Java 23, and Lucene to #612f0da4a4ce3a133b40402a87ec5cf7eeb290cc, but perf regression remains

IM (2025-05-17): Downgraded Linux kernel from 6.14.4 back to 6.12.4, recovering lost performance (temporarily)

IN (2025-05-22): Speed up exhaustive evaluation https://github.com/apache/lucene/pull/14679

IO (2025-05-29): Refactor main top-n bulk scorers to evaluate hits in a more term-at-a-time fashion https://github.com/apache/lucene/pull/14701, Speed up TermQuery https://github.com/apache/lucene/pull/14709

IP (2025-06-02): Keep evaluating conjunction one doc-at-a-time until dynamic pruning kicks in. https://github.com/apache/lucene/pull/14739

IQ (2025-06-03): Merge DocAndFreqBuffer and DocAndScoreBuffer https://github.com/apache/lucene/pull/14748

IR (2025-06-05): Swap out some simple PriorityQueue subclasses for one using a Comparator https://github.com/apache/lucene/pull/14705

IS (2025-06-06): Respect minCompetitiveScore in BlockMaxConjunctionBulkScorer https://github.com/apache/lucene/pull/14751

IT (2025-06-13): Upgrade Linux kernel from 6.14.4 to 6.15.2, curiously impacting many queries

IV (2025-06-26): Implement nextDocAndScores on CombinedFieldQuery and ConstantScoreQuery https://github.com/apache/lucene/pull/14834 https://github.com/apache/lucene/pull/14772

IW (2025-06-30): Using BatchScoreBulkScorer on CombinedFieldQuery https://github.com/apache/lucene/pull/14854

IX (2025-07-01): Use LessThan here rather than Comparator for some key PriorityQueues https://github.com/apache/lucene/pull/14871

IY (2025-07-04): Pre-calculate minRequiredScore to speedup filterCompetitiveHits https://github.com/apache/lucene/pull/14827

IZ (2025-07-07): Use branchless way to speedup filterCompetitiveHits https://github.com/apache/lucene/pull/14906

JA (2025-07-13): Optimize bitset to array https://github.com/apache/lucene/pull/14935

JB (2025-07-17): Vectorize filterCompetitiveHits https://github.com/apache/lucene/pull/14896

JC (2025-07-24): Further improve filtering by score https://github.com/apache/lucene/pull/14970

JD (2025-07-29): Improve byte vector scoring by loading on v/s off-heap vectors more appropriately https://github.com/apache/lucene/pull/14874

JE (2025-08-06): GroupVarInt encoding for HNSW graphs https://github.com/apache/lucene/pull/14932

JF (2025-08-07): Add bulk off-heap scoring for float32 vectors https://github.com/apache/lucene/pull/14980

JG (2025-08-08): Change default readadvice back to NORMAL from RANDOM https://github.com/apache/lucene/pull/15040

JH (2025-08-13): Add call site pollution https://github.com/mikemccand/luceneutil/pull/436

JI (2025-08-21): Enable InfoStream when indexing vectors; better vectorize score computations https://github.com/apache/lucene/pull/15039

JJ (2025-08-25): Rewrite of the GroupVInt optimization without lambdas, varhandles and no code in subclasses https://github.com/apache/lucene/commit/ebfd863ac728f9abfcaa42fec7fce90b62900df5

JK (2025-09-02): Optimize TopScoreDocCollector with TernaryLongHeap for improved performance over Binary-LongHeap https://github.com/apache/lucene/commit/ac90517c17ef78a469c65868e2026461f6ddcddc

JL (2025-09-10): Bump block size to 256 https://github.com/apache/lucene/pull/15160

JM (2025-09-16): Off-heap quantized vector scoring for the Lucene99 vector format https://github.com/apache/lucene/pull/14863

JN (2025-09-21): Vectorise expand8 in ForUtil using JDK Vector API https://github.com/apache/lucene/pull/15198

JO (2025-09-25): Use new OSQ-based Lucene104 quantized vector format https://github.com/apache/lucene/pull/15169

JP (2025-10-10): Implement longValues for MultiFieldNormValues to speedup CombinedQuery https://github.com/apache/lucene/pull/15261

JQ (2025-12-07): Switch from Cohere v2 (768 dims, un-normalized) vectors to Cohere v3 (1024 dims, normalized to unit sphere, shuffled). since we use DOT_PRODUCT vector similarity, the un-normalized v2 vectors search was completely broken so we should not trust the large throughput drop on v3 upgrade is true: https://github.com/mikemccand/luceneutil/issues/497

JR (2026-01-29): whole system upgrade, including kernel, somehow causing massive slowdown https://github.com/apache/lucene/issues/15662

JS (2026-02-04): One off benchmark with downgraded (from 6.18.7-arch1-1 to fallback LTS kernel 6.12.67-1-lts #1 SMP PREEMPT_DYNAMIC) attempting to root-cause https://github.com/apache/lucene/issues/15662

JT (2026-02-06): One off nightly benchmark with downgraded Lucene to match the last good 01/22 run, but all system packages fully updated; attempting to root-cause https://github.com/apache/lucene/issues/15662

JU (2026-02-07): One off nightly benchmark with also downgraded JDK (25.0.2 -> 25.0.1), but all other system packages fully updated, and Lucene frozen on last good 1/22 run; attempting to root-cause https://github.com/apache/lucene/issues/15662

JV (2026-02-24): Fully fix the Jan 29 sudden massive regression: CPU governor back to 'performance', BIOS upgrade, fix memory clock speed from 2400 MHz -> 3200 MHz, turn all fans on, better cooling of NVMe SSDs

JW (2026-03-04): Re-enable JFR profiling in nightly tasks benchy, known to be ~5-7% QPS hit #3ff2b89c6d0ee36c2f4506b4b4a4f6efce424a8f

JX (2026-04-10): #539: optimize PKLookupTask impl