We ([ParadeDB](https://github.com/paradedb/paradedb)) have restored and been using the removed [index sorting](https://github.com/quickwit-oss/tantivy/issues/2352) feature in our Tantivy fork.
Our use case is sorting the index by Postgres' internal `ctid` identifier. Results returned from Tantivy must be checked against Postgres' visibility map, and checking them in ctid order is much more cache friendly, resulting in up to 80% speedups for certain queries.
This PR is split into 5 commits, corresponding to the index sorting reversal plus bug fixes we uncovered during our usage of index sorting.
| Commit | Maps to | What it does |
|---|---|---|
| `2aea0ad9f` | foundation ([#104](https://github.com/paradedb/tantivy/pull/104)) | Restore `SegmentComponent::TempStore` (revert of upstream #2815). Subsumes fork PR [#104](https://github.com/paradedb/tantivy/pull/104)'s CI fix. |
| `9205bcb0c` | [#92](https://github.com/paradedb/tantivy/pull/92) | Restore sort-by-field (single-segment + merge paths). |
| `39c790f0f` | [#101](https://github.com/paradedb/tantivy/pull/101) | Enable `sort_by` for `Str`/`Bytes` fast fields. |
| `9c4341a87` | [#105](https://github.com/paradedb/tantivy/pull/105) | Native typed numeric sort-key comparison (precision/NULL fix). |
| `2d9ba2418` | [#106](https://github.com/paradedb/tantivy/pull/106) | Preserve NULL ordering in numeric segment merges. |
We have discussed with the Tantivy maintainers and they indicated they would be open to this PR. Another motivation for landing this PR is we are planning on contributing a significant refactor that makes Tantivy's segment components extensible, and landing that without index sorting leads to too many conflicts.
Add a public rank(target) method on BlockSegmentPostings that returns the
number of docs with a doc id strictly smaller than target. It jumps to the
candidate block through the skip list and decodes a single block, so the cost
is O(skip-list entries) + one block decode rather than O(doc_freq).
This is a useful primitive for range counting over a posting list (e.g. number
of matches in a [lo, hi) doc-id window) without iterating every matched doc.
To support it, expose SkipReader::remaining_docs() (pub(crate)). Like seek(),
rank() advances the cursor forward only and must be called with non-decreasing,
valid (<= TERMINATED) targets. Adds a unit test covering multi-block lists and
the below-first / above-last / empty edge cases.
Closes#2285
The TermFrequencyRecorder was completely untested. Add five focused tests:
- term_frequency_recorder_has_term_freq: verifies the recorder
correctly advertises term-frequency support via has_term_freq()
- term_frequency_recorder_zero_docs: term_doc_freq() returns Some(0)
before any documents are recorded
- term_frequency_recorder_term_doc_freq_single_doc: one document with
two occurrences yields term_doc_freq() == Some(1)
- term_frequency_recorder_term_doc_freq_multiple_docs: three documents
with varying term frequencies yield term_doc_freq() == Some(3),
confirming the count tracks documents, not occurrences
- term_frequency_recorder_single_occurrence_per_doc: each of three
documents has exactly one occurrence
- term_frequency_recorder_high_frequency_doc: a single document with
1000 occurrences still yields term_doc_freq() == Some(1)
* Optimizing top K using Adrien Grand's ideas
https://jpountz.github.io/2025/08/28/compiled-vs-vectorized-search-engine-edition.html
* Suffix-sum pruning for multi-term intersection candidates
After scoring each secondary in Phase 2, check whether remaining
secondaries' block_max scores can still beat the threshold. Skip
to the next candidate early if impossible, avoiding expensive seeks
into later secondaries.
Improves three-term intersection by ~8% on the balanced benchmark
while keeping two-term performance neutral.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
* Claude CR comment
* Removed 16 term scorer limit.
---------
Co-authored-by: Paul Masurel <paul.masurel@datadoghq.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
The intersection algorithm made it possible for .seek(..) with values
lower than the current doc id, breaking the DocSet contract.
The fix removes the optimization that caused left.seek(..) to be replaced
by a simpler left.advance(..).
Simply doing so lead to a performance regression.
I therefore integrated that idea within SegmentPostings.seek.
We now attempt to check the next doc systematically on seek,
PROVIDED the block is already loaded.
Closes#2811
Co-authored-by: Paul Masurel <paul.masurel@datadoghq.com>
Removes the Write generics argument in PostingsSerializer.
This removes useless generic.
Prepares the path for codecs.
Removes one useless CountingWrite layer.
etc.
Co-authored-by: Paul Masurel <paul.masurel@datadoghq.com>
* seek_exact + cost based intersection
Adds `seek_exact` and `cost` to `DocSet` for a more efficient intersection.
Unlike `seek`, `seek_exact` does not require the DocSet to advance to the next hit, if the target does not exist.
`cost` allows to address the different DocSet types and their cost
model and is used to determine the DocSet that drives the intersection.
E.g. fast field range queries may do a full scan. Phrase queries load the positions to check if a we have a hit.
They both have a higher cost than their size_hint would suggest.
Improves `size_hint` estimation for intersection and union, by having a
estimation based on random distribution with a co-location factor.
Refactor range query benchmark.
Closes#2531
*Future Work*
Implement `seek_exact` for BufferedUnionScorer and RangeDocSet (fast field range queries)
Evaluate replacing `seek` with `seek_exact` to reduce code complexity
* Apply suggestions from code review
Co-authored-by: Paul Masurel <paul@quickwit.io>
* add API contract verfication
* impl seek_exact on union
* rename seek_exact
* add mixed AND OR test, fix buffered_union
* Add a proptest of BooleanQuery. (#2690)
* fix build
* Increase the document count.
* fix merge conflict
* fix debug assert
* Fix compilation errors after rebase
- Remove duplicate proptest_boolean_query module
- Remove duplicate cost() method implementations
- Fix TopDocs API usage (add .order_by_score())
- Remove duplicate imports
- Remove unused variable assignments
---------
Co-authored-by: Paul Masurel <paul@quickwit.io>
Co-authored-by: Pascal Seitz <pascal.seitz@datadoghq.com>
Co-authored-by: Stu Hood <stuhood@gmail.com>
* query: add DocSet cost hint and use it for intersection ordering
- Add DocSet::cost()
- Use cost() instead of size_hint() to order scorers in intersect_scorers
This isolates cost-related changes without the new seek APIs from
PR #2538
* add comments
---------
Co-authored-by: Pascal Seitz <pascal.seitz@datadoghq.com>
* add RegexPhraseQuery
RegexPhraseQuery supports phrase queries with regex. It supports regex
and wildcards. E.g. a query with wildcards:
"b* b* wolf" matches "big bad wolf"
Slop is supported as well:
"b* wolf"~2 matches "big bad wolf"
Regex queries may match a lot of terms where we still need to
keep track which term hit to load the positions.
The phrase query algorithm groups terms by their frequency
together in the union to prefilter groups early.
This PR comes with some new datastructures:
SimpleUnion - A union docset for a list of docsets. It doesn't do any
caching and is therefore well suited for datasets with lots of skipping.
(phrase search, but intersections in general)
LoadedPostings - Like SegmentPostings, but all docs and positions are loaded in
memory. SegmentPostings uses 1840 bytes per instance with its caches,
which is equivalent to 460 docids.
LoadedPostings is used for terms which have less than 100 docs.
LoadedPostings is only used to reduce memory consumption.
BitSetPostingUnion - Creates a `Posting` that uses the bitset for docid
hits and the docsets for positions. The BitSet is the precalculated
union of the docsets
In the RegexPhraseQuery there is a size limit of 512 docsets per PreAggregatedUnion,
before creating a new one.
Renamed Union to BufferedUnionScorer
Added proptests to test different union types.
* cleanup
* use Box instead of Vec
* use RefCell instead of term_freq(&mut)
* remove wildcard mode
* move RefCell to outer
* clippy
The previous way to address the problem was to replace \u{0000}
with 0 in different places.
This logic had several flaws:
Done on the serializer side (like it was for the columnar), there was
a collision problem.
If a document in the segment contained a json field with a \0 and
antoher doc contained the same json field but `0` then we were sending
the same field path twice to the serializer.
Another option would have been to normalizes all values on the writer
side.
This PR simplifies the logic and simply ignore json path containing a
\0, both in the columnar and the inverted index.
Closes#2442
* reduce number of allocations
Explanation makes up around 50% of all allocations (numbers not perf).
It's created during serialization but not called.
- Make Explanation optional in BM25
- Avoid allocations when using Explanation
* use Cow
In JSON Object field the presence of term frequencies depend on the
field.
Typically, a string with postiions indexed will have positions
while numbers won't.
The presence or absence of term freqs for a given term is unfortunately
encoded in a very passive way.
It is given by the presence of extra information in the skip info, or
the lack of term freqs after decoding vint blocks.
Before, after writing a segment, we would encode the segment correctly
(without any term freq for number in json object field).
However during merge, we would get the default term freq=1 value.
(this is default in the absence of encoded term freqs)
The merger would then proceed and attempt to decode 1 position when
there are in fact none.
This PR requires to explictly tell the posting serialize whether
term frequencies should be serialized for each new term.
Closes#2251
* docid deltas while indexing
storing deltas is especially helpful for repetitive data like logs.
In those cases, recording a doc on a term costed 4 bytes instead of 1
byte now.
HDFS Indexing 1.1GB Total memory consumption:
Before: 760 MB
Now: 590 MB
* use scan for delta decoding
* add support for delta-1 encoding posting list
* encode term frequency minus one
* don't emit tf for json integer terms
* make skipreader not pub(crate) mutable
* fix windows build (#1)
* Fix windows build
* Add doc traits
* Add field value iter
* Add value and serialization
* Adjust order
* Fix bug
* Correct type
* Fix generic bugs
* Reformat code
* Add generic to index writer which I forgot about
* Fix missing generics on single segment writer
* Add missing type export
* Add default methods for convenience
* Cleanup
* Fix more-like-this query to use standard types
* Update API and fix tests
* Add doc traits
* Add field value iter
* Add value and serialization
* Adjust order
* Fix bug
* Correct type
* Rebase main and fix conflicts
* Reformat code
* Merge upstream
* Fix missing generics on single segment writer
* Add missing type export
* Add default methods for convenience
* Cleanup
* Fix more-like-this query to use standard types
* Update API and fix tests
* Add tokenizer improvements from previous commits
* Add tokenizer improvements from previous commits
* Reformat
* Fix unit tests
* Fix unit tests
* Use enum in changes
* Stage changes
* Add new deserializer logic
* Add serializer integration
* Add document deserializer
* Implement new (de)serialization api for existing types
* Fix bugs and type errors
* Add helper implementations
* Fix errors
* Reformat code
* Add unit tests and some code organisation for serialization
* Add unit tests to deserializer
* Add some small docs
* Add support for deserializing serde values
* Reformat
* Fix typo
* Fix typo
* Change repr of facet
* Remove unused trait methods
* Add child value type
* Resolve comments
* Fix build
* Fix more build errors
* Fix more build errors
* Fix the tests I missed
* Fix examples
* fix numerical order, serialize PreTok Str
* fix coverage
* rename Document to TantivyDocument, rename DocumentAccess to Document
add Binary prefix to binary de/serialization
* fix coverage
---------
Co-authored-by: Pascal Seitz <pascal.seitz@gmail.com>
With tantivy 0.20 the minimum memory consumption per SegmentWriter increased to
12MB. 7MB are for the different fast field collectors types (they could be
lazily created). Increase the minimum memory from 3MB to 15MB.
Change memory variable naming from arena to budget.
closes#2156
* tokenizer-api: reduce Tokenizer overhead
Previously a new `Token` for each text encountered was created, which
contains `String::with_capacity(200)`
In the new API the token_stream gets mutable access to the tokenizer,
this allows state to be shared (in this PR Token is shared).
Ideally the allocation for the BoxTokenStream would also be removed, but
this may require some lifetime tricks.
* simplify api
* move lowercase and ascii folding buffer to global
* empty Token text as default
Applied this command to the code, making it a bit shorter and slightly
more readable.
```
cargo +nightly clippy --all-features --benches --tests --workspace --fix -- -A clippy::all -W clippy::uninlined_format_args
cargo +nightly fmt --all
```
* add term hashmap benchmark
* refactor arena hashmap
add inlines
remove occupied array and use table_entry.is_empty instead (saves 4 bytes per entry)
reduce saturation threshold from 1/3 to 1/2 to reduce memory
use u32 for UnorderedId (we have the 4billion limit anyways on the Columnar stuff)
fix naming LinearProbing
remove byteorder dependency
memory consumption went down from 2Gb to 1.8GB on indexing wikipedia dataset in tantivy
* Update stacker/src/arena_hashmap.rs
Co-authored-by: Paul Masurel <paul@quickwit.io>
---------
Co-authored-by: Paul Masurel <paul@quickwit.io>
The new fast field code, based on columnar, had a larger minimum memory
footprint, causing the first docuemnt to trigger a flush of the asegment
in this unit test.
This PR prevents the allocation of a large capacity for the different hashmap tables
using in the columnar writer.
Closes#1859
* Make nightly Clippy mostly happy.
* Document how to produce TermSetQuery queries using QueryParser.
* Enable construction of queries using FuzzyTermQuery via the QueryParser
* Use FxHashMap instead of HashMap in the QueryParser as these hash tables are not exposed to DoS attacks.
* Use a struct instead of a tuple to improve readability.