News - 15 series — Groonga v16.1.0 documentation

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# News - 15 series

## Release 15.2.5 - 2026-01-30

### Fixes

#### Fixed a compatibility bug with the `ShortBinary`, `Binary`, `LongBinary`, and `JSON` types

Fixed a bug that prevented the `ShortBinary`, `Binary`, and `LongBinary` types added in Release 15.1.8 - 2025-10-31, and the `JSON` type added in Release 15.2.3 - 2026-01-15, from working correctly in databases created before those versions.

Additionally, a bug that caused Groonga databases created with versions before Release 15.2.1 - 2025-12-02 to crash when opened in Release 15.2.3 - 2026-01-15 or later, when the schema command was executed, has been fixed.

When upgrading from Groonga versions before 15.2.1, please upgrade to version 15.2.5 or later.

You can resolve this issue by upgrading to version 15.2.5, even if you have already upgraded to versions 15.2.3 or 15.2.4.

## Release 15.2.4 - 2026-01-29

### Improvements

#### [grndb] Added support for closing used object immediately in `grndb check`.

We can reduce memory usage by this.

We used to leave used object opened on memory. We needed too much memory if we checked a large database by using `grndb check`. Therefore, `grndb check` is not practical on low-memory environment because it takes a long time to complete check.

We can complete `grndb check` within a realistic time even if we use low-memory environment by this modification.

## Release 15.2.3 - 2026-01-15

### Fixes

#### Fixed a bug that Groonga couldn’t find records that were added after index construction when `centroid_column` was used

If this bug occurs, Groonga doesn’t return records that added as below.

    plugin_register language_model/knn

    table_create Data TABLE_NO_KEY
    column_create Data text COLUMN_SCALAR ShortText
    column_create Data rabitq_code COLUMN_SCALAR ShortBinary

    load --table Data
    [
    {"text": "I am a boy."}
    ]

    table_create RaBitQ TABLE_HASH_KEY UInt32 \
      --default_tokenizer \
        'TokenLanguageModelKNN("model", "hf:///groonga/multilingual-e5-base-Q4_K_M-GGUF", \
                               "centroid_column", "centroid", \
                               "code_column", "rabitq_code", \
                               "passage_prefix", "passage: ", \
                               "query_prefix", "query: ")'
    column_create RaBitQ centroid COLUMN_VECTOR Float32
    column_create RaBitQ data_text COLUMN_INDEX Data text

    load --table Data
    [
    {"text": "This is an apple."}
    ]

    select Data \
      --filter 'language_model_knn(text, "fruit")' \
      --output_columns text
    [
      [
        0,
        0.0,
        0.0
      ],
      [
        [
          [
            1
          ],
          [
            [
              "text",
              "ShortText"
            ]
          ],
          [
            "I am a boy."
          ]
        ]
      ]
    ]

### Experimental features

> These features are still experimental and unstable. We must not use these features in production.

#### Bundled OpenZL

OpenZL is a compression framework. It provides high compression ratios and high speed.

We can specify `COMPRESS_OPENZL` in `column_create`, but if we specify `COMPRESS_OPENZL`, it doesn’t work yet. Because we haven’t implemented the feature for compression and decompression.

#### Added support for JSON type

We can `load` and `dump` against some data types. However, we don’t implement other features yet.

## Release 15.2.1 - 2025-12-02

### Improvements

#### [column_create] Added support for progress log of index construction

You can view the progress log during offline index construction.

The default log level is `debug`. This means you must enable debug level logging to view progress logs. If you set the log level to `notice`, you can view progress logs without other debug logs.

#### [TokenLanguageModelKNN] Added `centroid_column` option

This option is for large embeddings with more than 1025 dimensions (more than 4100 bytes). Groonga table keys must be 4 KiB or smaller. Embeddings larger than 4 KiB cannot be stored as keys.

You can use this option to store large embeddings in a column instead of in the table key. Specify the column for storing embeddings and add it to the table for the index as below.

    table_create LargeCentroids TABLE_HASH_KEY UInt32 \
      --default_tokenizer \
          'TokenLanguageModelKNN("model", "hf:///groonga/multilingual-e5-base-Q4_K_M-GGUF", \
                                 "centroid_column", "centroid", \
                                 "code_column", "embedding_code", \
                                 "passage_prefix", "passage: ", \
                                 "query_prefix", "query: ")'
    column_create LargeCentroids centroid COLUMN_VECTOR Float32
    column_create LargeCentroids data_content COLUMN_INDEX Memos content

#### [TokenLanguageModelKNN] Added `n_gpu_layers` option

Specify the number of GPU layers to use for language model. If not specified, Groonga uses GPU as much as possible.

In most cases, you don’t need to set this option explicitly.

To disable GPU usage, set `n_gpu_layers` to 0.

#### [language_model_knn] Added `k` option

Specify the number of records to return. If you don’t set this option, the upper limit of the number of returned records is `10`.

You can specify a negative value. It means: (number of matched records) + `k` + 1. For example, `"{ "k" : -1 }"` outputs all records. It’s a very useful value to show all records.

### Fixes

#### Fixed a bug that causes overflow in the key of `TABLE_PAT_KEY` tables.

This issue is found in PGroonga by pgroonga/pgroonga#901. If you execute offline index construction against a column that has a large size value (When the size of a token is 4096 bytes after tokenization), the index may be broken.

Reported by lilydjwg.

### Thanks

- lilydjwg

## Release 15.2.0 - 2025-11-10

In this release, we provide packages for Ubuntu that are provided for PPA (Personal Package Archive) again by resolving the issue causing the build failure.

### Fixes

[Ubuntu] Provided packages for Ubuntu that are provided for PPA (Personal Package Archive) again

We couldn’t provide packages for Ubuntu that are provided for PPA (Personal Package Archive) in Groonga 15.1.8 and 15.1.9 due to a build failure in Launchpad.

In this release, we provide packages for Ubuntu again by resolving the issue causing the build failure.

## Release 15.1.9 - 2025-11-05

In this release, we added support for parallel vectorization.

### Improvements

#### Added support for parallel vectorization

We can execute parallel vectorization in language_model_knn, TokenLanguageModelKNN, and language_model_vectorize.

If we set `--n-default-workers=-1`, Groonga executes in parallel using up to as many threads as the number of CPU cores; however, this setting will not be optimal because it’s based on the number of CPUs.

We must check GPU usage not CPU usage for the optimal number of workers.

#### [TokenLanguageModelKNN] Added support for prefix

Some models such as multilingual-e5 require a prefix for search target texts and query texts. This improvement adds support for these cases.

- `passage_prefix` is the prefix for search target text.

- `query_prefix` is the prefix for query text.

For example, we can set `passage:` prefix in search target text and `query:` prefix in query text as below.

    TokenLanguageModelKNN("model", "hf:///groonga/multilingual-e5-base-Q4_K_M-GGUF", \
                          "code_column", "rabitq_code", \
                          "passage_prefix", "passage: ", \
                          "query_prefix", "query: ")

## Release 15.1.8 - 2025-10-31

In this release, semantic search is supported.

### Improvements

#### [status] Added `.["features"]["faiss"]` entry

The `.["features"]` entry shows whether each feature is enabled or not like the following:

    [
      ["..."],
      {
        "...": "...",
        "features": {
          "nfkc": true,
          "mecab": true,
          "...": "..."
        },
        "...": "..."
      }
    ]

This release added `faiss` to the `.["features"]` entry:

    [
      ["..."],
      {
        "...": "...",
        "features": {
          "nfkc": true,
          "mecab": true,
          "...": "...",
          "faiss": true,
          "...": "..."
        },
        "...": "..."
      }
    ]

You can use `.["features"]["faiss"]` to know whether Faiss is enabled or not.

You need the Faiss support to use semantic search described next.

#### Supported semantic search

This feature is still experimental and unstable.

Added TokenLanguageModelKNN tokenizer and language_model_knn function. Using these together you can do semantic search.

Here is an example of semantic search.

    select Data \
      --filter 'language_model_knn(text, "male child")' \
      --output_columns text

    [
      [
        0,
        0.0,
        0.0
      ],
      [
        [
          [
            3
          ],
          [
            [
              "text",
              "ShortText"
            ]
          ],
          [
            "I am a boy."
          ],
          [
            "This is an apple."
          ],
          [
            "Groonga is a full text search engine."
          ]
        ]
      ]
    ]

The important feature is that it searches using text, just like keyword search. Internally, Groonga creates embedding automatically and use it for semantic search.

Users do not need to create embeddings and search using them. You can do semantic search with text, just like keyword search.

We omitted examples, but the same works when loading text for search. Simply load text into Groonga as before, and you can do semantic search. Users don’t need to create embeddings and load them. This is because Groonga automatically generates embeddings as well.

For details on setting up indexes and more, see the pages for TokenLanguageModelKNN tokenizer and language_model_knn function.

#### [language_model_vectorize] Added support for auto download from Hugging Face

This feature is still experimental and unstable.

Specifying a Hugging Face URI in `model_name` will automatically download the language model. The model is downloaded during the first execution and located in the Groonga database directory. Subsequent executions use the local model files.

    language_model_vectorize("hf:///groonga/all-MiniLM-L6-v2-Q4_K_M-GGUF", content)

Using this feature is useful because Groonga handles the download and placement.

#### [Data types] Add `ShortBinary`, `Binary` and `LongBinary`

This feature is still experimental and unstable.

## Release 15.1.7 - 2025-09-29

In this release, `NormalizerNFKC` can normalize Japanese iteration marks and fixed installation failure on AlmaLinux 10.

### Improvements

#### [grndb] Improved error handling for large database files

Previously, `grndb` terminated abnormally when processing database files that exceeded the filesystem stat limit (such as files files larger than 2GB on Windows). In this release, when `grndb` processes such files in the Groonga database directory (the db file and related db.* files), it records an error for each problematic file and continues to completion without aborting.

#### [unify_iteration_mark] Added support for iteration marks with `unify_iteration_mark` option

The `unify_iteration_mark` option now supports additional iteration mark characters. This option treats iteration marks as repeats of the immediately preceding character as below.

- Hiragana Iteration Mark ゝ (U+309D)

- Hiragana Voiced Iteration Mark ゞ (U+309E)

- Katakana Iteration Mark ヽ (U+30FD)

- Katakana Voiced Iteration Mark ヾ (U+30FE)

- Ideographic Iteration Mark 々 (U+3005) - limitation: only repeats the immediately preceding single character

- Vertical Ideographic Iteration Mark 〻 (U+303B) - limitation: only repeats the immediately preceding single character

Here is an example of using `unify_iteration_mark` option.

    normalize \
      'NormalizerNFKC("unify_iteration_mark", true)' \
      "こゝろ"
    [
      [
        0,
        1758763896.821301,
        0.0001749992370605469
      ],
      {
        "normalized": "こころ",
        "types": [
        ],
        "checks": [
        ]
      }
    ]

Note

For Ideographic Iteration Mark (々) and Vertical Ideographic Iteration Mark (〻), this feature only repeats the immediately preceding single character. Patterns beyond repeat the previous one character are not supported like the following cases.

Examples:

- “部分々々” -> “部分部分”

- “古々々米” -> “古古古米”

#### Added new command to list available commands

A new `command_list` command has been added that returns a list of all available Groonga commands. Currently, this command returns only the command ID and name for each command. Using this command could enable automatic generation of client library APIs and help implement Groonga MCP (Model Context Protocol) servers. In future releases, we plan to expand the output to include command summaries, descriptions, and detailed argument information.

    command_list
    [
      [
        0,
        1758764636.669152,
        0.0002362728118896484
      ],
      {
        "cache_limit": {
          "id": 150,
          "name": "cache_limit"
        },
        ...
      }
    ]

#### [TokenFilterStem] Added support for non-ASCII alphabets

GH-2539

Reported by Tsai, Xing Wei

Previously, the `TokenFilterStem` filter only worked with ASCII alphabets. Now it supports stemming for non-ASCII alphabets such as Arabic.

Here is an example of using `TokenFilterStem` with Arabic text:

    table_create Terms TABLE_PAT_KEY ShortText \
      --default_tokenizer TokenNgram \
      --normalizer 'NormalizerNFKC("version", "16.0.0")' \
      --token_filters 'TokenFilterStem("algorithm", "arabic")'

    table_tokenize Terms "الكتاب مفيد" --mode ADD
    [
      [
        0,
        0.0,
        0.0
      ],
      [
        {
          "value": "كتاب",
          "position": 0,
          "force_prefix": false,
          "force_prefix_search": false
        },
        {
          "value": "مفيد",
          "position": 1,
          "force_prefix": false,
          "force_prefix_search": false
        }
      ]
    ]

### Fixes

#### [AlmaLinux] Fixed installation failure on AlmaLinux 10

Previously, installation could fail with a dnf GPG check error due to the following outdated RPM GPG key in groonga-release. We’ve removed the old key and now ship only the RSA4096 key, so installs work as expected now.

    $ dnf install -y --enablerepo=epel --enablerepo=crb groonga
    ...
    error: Certificate 72A7496B45499429:
      Policy rejects 72A7496B45499429: No binding signature at time 2025-09-24T09:35:25Z
    Key import failed (code 2). Failing package is: groonga-15.1.5-1.el10.x86_64
     GPG Keys are configured as: file:///etc/pki/rpm-gpg/RPM-GPG-KEY-34839225, file:///etc/pki/rpm-gpg/RPM-GPG-KEY-45499429
    The downloaded packages were saved in cache until the next successful transaction.
    You can remove cached packages by executing 'dnf clean packages'.
    Error: GPG check FAILED

##### Who should upgrade?

Most users do not need to upgrade. Only users who installed groonga-release on AlmaLinux 10 before 2025/09/24 need to upgrade to the latest package using the steps below. If you installed groonga-release on AlmaLinux 10 on or after 2025/09/24, no action is required.

    $ sudo dnf upgrade --refresh groonga-release

After upgrading the package, groonga-release contains only the new key:

    $ dnf repoquery -l --installed groonga-release
    /etc/pki/rpm-gpg
    /etc/pki/rpm-gpg/RPM-GPG-KEY-34839225
    /etc/yum.repos.d
    /etc/yum.repos.d/groonga-almalinux.repo
    /etc/yum.repos.d/groonga-amazon-linux.repo

### Thanks

- Tsai, Xing Wei

## Release 15.1.5 - 2025-08-29

In this release, we supported `KEY_LARGE` flag for `TABLE_PAT_KEY`!

Debian 13 “Trixie” has been released on 9 August 2025. Groonga is already supported on Debian 13! Please try it!

### Improvements

#### [table_create] Added support for `KEY_LARGE` flag for `TABLE_PAT_KEY`

You can now use the `KEY_LARGE` flag with `TABLE_PAT_KEY` tables to expand the maximum total key size from 4GiB to 1TiB, similar to `TABLE_HASH_KEY` tables as below. This allows you to store more keys in total.

    table_create LargePaths TABLE_PAT_KEY|KEY_LARGE ShortText

#### [NormalizerNFKC] Added support for `unify_hyphen_and_prolonged_sound_mark` and `remove_symbol` combination

Previously, when both `unify_hyphen_and_prolonged_sound_mark` and `remove_symbol` options were enabled together, This combination didn’t remove hyphen characters as expected because the hyphen characters were not properly treated as symbols to be removed.

This release fixes this issue. So, hyphen characters are properly removed from the normalized text as below.

    normalize \
      'NormalizerNFKC("remove_symbol", true, \
      "unify_hyphen_and_prolonged_sound_mark", true)' \
      "090ー1234-5678"
    [
      [
        0,
        1756363926.409565,
        0.0003023147583007812
      ],
      {
        "normalized": "09012345678",
        "types": [
        ],
        "checks": [
        ]
      }
    ]

#### [AlmaLinux] Added support for AlmaLinux 10

AlmaLinux 10 packages are now available. You can install Groonga on AlmaLinux 10 using the standard package installation methods.

### Fixes

#### [Others: Build with CMake] Fixed how to build/install

GH-2479

Patched by Tsutomu Katsube

The documentation included an incorrect `-B` option in the `cmake --build` and `cmake --install` commands, which caused build errors.

The corrected commands are now:

    cmake --build <Build directory path>
    cmake --install <Build directory path>

#### [truncate] Fixed a bug where `KEY_LARGE` flag was lost after executing `truncate` command

This issue meant that when you executed the `truncate` command on a `TABLE_HASH_KEY` table with the `KEY_LARGE` flag, the table could no longer hold more than 4 GiB of total key data, because the `KEY_LARGE` flag was removed during the truncation.

#### [grndb] Fixed a bug that the database checked by `grndb check` command was not enough

The issue occurred because the `grndb check` command did not check part of the database files.

However, even without this modification, grndb check correctly returns the results of table and column checks. `grndb cehck` can check database correctly by this modification.

### Thanks

- Tsutomu Katsube

## Release 15.1.4 - 2025-07-29

In this release, we fixed a bug in the interval calculation between phrases in `*ONPP` operator.

### Fixes

#### [Ordered near phrase product search] Fixed a bug in the interval calculation between phrases

This problem may occur when we use `*ONPP` with `MAX_ELEMENT_INTERVAL` such as `*ONPP-1,0,10"(abc bcd) (defg)"`. If you don’t use `MAX_ELEMENT_INTERVAL`, this problem doesn’t occur.

Please refer to the following links for usage and syntax of `*ONPP`.

- [`*ONPP` in query syntax] Ordered near phrase product search condition

- [`*ONPP` in script syntax] Ordered near phrase product search operator

If this problem occurs, the following things may happen.

- Groonga may return records that shouldn’t be matched.

- Groonga may not return records that should be matched.

## Release 15.1.3 - 2025-07-18

### Improvements

#### [Apache Arrow] Added support for Apache Arrow C++ 21.0.0

## Release 15.1.2 - 2025-07-07

### Improvements

#### [Windows] Drop support for Groonga package that is built with Visual Studio 2019

We don’t provide the following packages since this release.

- groonga-xx.x.x-x64-vs2019.zip

- groonga-xx.x.x-x64-vs2019-with-vcruntime.zip

### Fixes

#### [Near phrase search] Fixed a bug that interval between phrases calculation

This problem may occur when we use `*NP`, `*NPP`, or `*ONP` with `MAX_ELEMENT_INTERVAL` as below.

- `*NP-1,0,12"abc ef"`

- `*NPP-1,0,10"(abc bcd) (ef)"`

- `*ONP-1,0,5|6 "abc defghi jklmnop"`

If you don’t use `MAX_ELEMENT_INTERVAL`, this problem doesn’t occur.

Please refer to the following links about usage and syntax of `*NP`, `*NPP`, or `*ONP`.

- [`*NP` in query syntax] Near phrase search condition

- [`*NP` in script syntax] Near phrase search operator

- [`*NPP` in query syntax] Near phrase product search condition

- [`*NPP` in script syntax] Near phrase product search operator

- [`*ONP` in query syntax] Ordered near phrase search condition

- [`*ONP` in script syntax] Ordered near phrase search operator

If this problem occurs, the following things may happen.

- Groonga may return records shouldn’t be a hit.

- Groonga may not return records that should be returned as hits.

## Release 15.1.1 - 2025-06-02

This release updates TokenMecab to preserve user-defined entries with spaces as single tokens.

### Improvements

#### TokenMecab: Fix unintended splitting of user-defined entries with spaces

Previously, TokenMecab split user-defined entries containing spaces (e.g., “search engine”) into separate tokens (“search” and “engine”). This release fixes this issue, so entries with embedded spaces are now preserved and handled as single tokens like “search engine” as follows.

    tokenize TokenMecab "search engine" --output_pretty yes
    [
      [
        0,
        1748413131.972704,
        0.0003032684326171875
      ],
      [
        {
          "value": "search engine",
          "position": 0,
          "force_prefix": false,
          "force_prefix_search": false
        }
      ]
    ]

### Fixes

#### Fixed many typos in documentation

GH-2332, GH-2333, GH-2334, GH-2335, GH-2336, GH-2337, GH-2338

Patched by Vasilii Lakhin.

### Thanks

- Vasilii Lakhin

## Release 15.0.9 - 2025-05-08

This release adds the tokenizer’s option to make token inspection simpler and improves negative-division semantics for unsigned integer.

### Improvements

#### tokenize/table_tokenize: Added output_style option

This output_style option to the tokenize/table_tokenize command makes it easier to focus on the tokens when you don’t need the full attribute set.

Here is example of using output_style option.

    tokenize TokenNgram "Fulltext Search" --output_style simple
    [
      [
        0,
        1746573056.540744,
        0.0007045269012451172
      ],
      [
        "Fu",
        "ul",
        "ll",
        "lt",
        "te",
        "ex",
        "xt",
        "t ",
        " S",
        "Se",
        "ea",
        "ar",
        "rc",
        "ch",
        "h"
      ]
    ]

#### Clarified `X / negative value` semantics

Previously, only dividing `X` by `-1`/`1.0` returns `-X` for unsigned integers. From this release, dividing by any negative value will yield the mathematically expected negative result as follows.

- Before: `X / -2` might not return `-(X / 2)`.

- After: `X / -2` always returns `-(X / 2)`.

This is a backward incompatible change but we assume that no user depends on this behavior.

## Release 15.0.4 - 2025-03-29

### Improvements

#### Clarified `X / -1` and `X / -1.0` semantics

In many languages, `X / -1` and `X / -1.0` return `-X`. But Groonga may not return `-X` when `X` is unsigned integer.

`X / -1` and `X / -1.0` always return `-X` from this release.

This is a backward incompatible change but we assume that no user depends on this behavior.

## Release 15.0.3 - 2025-03-10

### Improvements

#### Offline index construction: Added support for parallel construction with TABLE_HASH_KEY lexicon

Parallel offline index construction iterates sorted terms internally. TABLE_PAT_KEY and TABLE_PAT_KEY can do it effectively because they are based on tree. But TABLE_HASH_KEY can’t do it effectively because it’s not based on tree. So we didn’t support parallel offline index construction with TABLE_HASH_KEY lexicon.

This release adds support for parallel offline index construction with TABLE_HASH_KEY lexicon. It sort terms in a normal way. So it’s not so effective. Parallel offline index construction with TABLE_HASH_KEY lexicon will be slower than TABLE_PAT_KEY/TABLE_DAT_KEY. But it may be faster than sequential offline index construction with TABLE_HASH_KEY lexicon.

## Release 15.0.2 - 2025-02-21

### Fixes

#### Offline index construction: Fixed a bug that options may be ignored in parallel construction

Groonga may ignore options of Normalizers, Tokenizers and/or Token filters in the target index when offline index construction is executed in parallel.

This issue may occur when:

- Offline index construction is executed in parallel.

- Normalizers, Tokenizers, and/or Token filters options are used.

If NormalizerTable is used and this happens, the offline index construction is failed. Because NormalizerTable has a required parameter. If options are ignored, the required parameter is missing.

## Release 15.0.1 - 2025-02-20

### Improvements

#### [Ubuntu] Dropped support for Ubuntu 20.04 (Focal Fossa)

Ubuntu 20.04 will reach EOL in May 2025, so support for it has been dropped starting with this release.

## Release 15.0.0 - 2025-02-09

This is our annual major release! This release doesn’t have any backward incompatible changes! So you can upgrade Groonga without migrating your existing databases. You can still use your existing databases as-is.

### Improvements

#### TABLE_PAT_KEY: Added support for Float32 as key type

GH-2211

TABLE_PAT_KEY encodes/decodes numeric keys for fast search internally. So TABLE_PAT_KEY must know how to encode/decode keys. TABLE_PAT_KEY didn’t know how to encode/decode Float32 before this release. Now, TABLE_PAT_KEY can encode/decode Float32. So you can use Float32 as a TABLE_PAT_KEY key type like other numeric types such as Int32 and Float now.