# groonga - An open-source fulltext search engine and column store.

- 日本語

# News

## Release 6.0.5 - 2016-06-29

### Improvements

- [io_flush] Marked as stable command.
- [mruby] Supported to optimize prefix search by estimating data size efficiently
- [fuzzy_search] Supported `max_distance` option as 3rd argument to specify it easily. [GitHub#553] [Patch by Naoya Murakami]
- [query_expand] Supported command to expand query. It is useful if there are many synonyms.
- [select] Supported `--drilldown` with `command_version=3`. [groonga-dev,04055] [Reported by Naoya Murakami]
- Removed needless code from `grn_table_select_sequential()`. [GitHub#560] [Reported by Sho Minagawa]
- grn_table_setoperation(): Changed to update score instead of overwriting by `GRN_OP_ADJUST`. This change is introduced to keep consistency with `grn_ii_posting_add()`. [groonga-dev,04058] [Reported by Naoya Murakami]
- [dump] Reduced the max opened table/column files when 1 thread mode.

### Fixes

- [CMake][Windows] Fixed to install missing mruby script. [groonga-dev,04040] [Reported by Soichiro Kiyokawa]
- [Windows] Changed to bundle msgpack-c.
- [Others] Fixed a typo about default database encoding (utf8). [GitHub#549] [Patch by IWAI, Masaharu]
- [ユーザーと協力して開発をうまく進めていくための指針] Fixed a typo about product name (Twitter). [GitHub#550] [Patch by IWAI, Masaharu]
- Fixed a bug that specific records are not included into search result when multiple index column is created with `WITH_SECTION` flag. [GitHub#551]
- Fixed a crash bug that searching while loading data with `GRN_II_CURSOR_SET_MIN_ENABLE=yes`. `GRN_II_CURSOR_SET_MIN_ENABLE` is enabled by default since Groonga 6.0.3.
- [Token filters] Fixed thread unsafe implementation.
- [doc] Fixed a typo in 6.0.4 release entry. [GitHub#559] [Patch by cafedomancer]

### Thanks

- Naoya Murakami
- Soichiro Kiyokawa
- IWAI, Masaharu
- cafedomancer

## Release 6.0.4 - 2016-06-06

It's a bug fix release of 6.0.3. It's recommend that Groonga 6.0.3 users upgrade to 6.0.4. This release fixes some search related problems.

### Fixes

- [select] Fixed a bug that `--drilldown` against a temporary column created by `--columns` refers freed memory.
- Fixed a bug that search with large index may refer invalid data. It takes a long time to return search result. [GitHub#548][groonga-dev,04028][Reported by Atsushi Shinoda]

### Thanks

- Atsushi Shinoda

## Release 6.0.3 - 2016-05-29

### Improvements

- [experimental] Added `GRN_II_OVERLAP_TOKEN_SKIP_ENABLE` and `GRN_NGRAM_TOKENIZER_REMOVE_BLANK_DISABLE` environment variables to improve performance of N-gram tokenizer. [GitHub#533][Patch by Naoya Murakami]

- [table_create] Stopped to ignore nonexistent default tokenizer, normalizer or token filters. In the previous versions, Groonga ignored a typo in `--default_tokenizer`, `--normalizer` or `--token_filters` parameter silently. It caused a delay in finding problems.

- [select] output_columns v1: Supported expression such as `snippet_html(...)` in output_columns.

- [select] Removed a limitation about the number of labeled drilldowns. In the previous versions, the number of max labeled drilldowns is limited to 10.

- [number_classify] Added a number plugin. Use `number_classify` function to classify by value.

- Added a time plugin. Use `time_classify_second`, `time_classify_minute`, `time_classify_hour`, `time_classify_day`, `time_classify_week`, `time_classify_month`, `time_classify_year` function to classify by value.

- [select] Supported dynamic column creation which is used in `output_columns`, `drilldown` or `sortby` [GitHub#539,#541,#542,#544,#545][Patch by Naoya Murakami]:

      select \
        --columns[LABEL].stage filtered \
        --columns[LABEL].type ShortText \
        --columns[LABEL].flags COLUMN_SCALAR \
        --columns[LABEL].value 'script syntax expression' \
        ...

- [experimental][select] Improved performance for range/equal search and enough filtered case. Set `GRN_TABLE_SELECT_ENOUGH_FILTERED_RATIO` environment variable to enable this feature.

- [select] Supported index used search for filtered tables.

- Supported to detect changed database isn't closed. This feature is useful to check database corruption when Groonga is crashed unexpectedly.

- [grndb] Supported detecting database wasn't closed successfully case.

- Added `--drilldown_filter`.

- Supported `filter` in labeled drilldown.

- Improved performance for using [between] without index. By between() optimization, there is a case that range search is 100x faster than the previous version of between().

- [record_number] Supported window function.

- [experimental][select] Supported `--slices`.

- [select] Deprecated `--sortby` and `--drilldown_sortby`. Use `--sort_keys` and `-drilldown_sort_keys` instead.

- [select] Deprecated `--drilldown[...]`. Use `--drilldowns[...]` instead.

- Added [Command version] 3. It uses object literal based envelope.

- [groonga-httpd] Updated bundled nginx version to 1.11.0.

### Fixes

- [select] output_columns v2: Fixed a bug that `*` isn't expand to columns correctly.
- Fixed a bug that 1usec information is lost for time value.
- Fixed a crash bug when a mruby plugin is initialized with multiple threads.
- Fixed a bug that static indexing crashes if a posting list is very long. This bug may occur against enormous size of database. [GitHub#546]

### Thanks

- Naoya Murakami

## Release 6.0.2 - 2016-04-29

### Improvements

- Supported bool in comparison operators (`>`, `>=`, `<`, `<=`). TRUE is casted to 1. FALSE is casted to 0. Thus you specify function which returns boolean value in comparison.
- [groonga-http][Request timeout] Supported `request_timeout` parameter. Canceled request returns `HTTP/1.1 408 Request Timeout` status code.
- [table_tokenize] Added `index_column` option. [GitHub#534] [Patch by Naoya Murakami]
- [table_tokenize] Supported to output `estimated_size`. [GitHub#518] [Patch by Naoya Murakami]
- [geo_in_rectangle] Supported to work without index. In this case, sequential search is executed as a fallback.
- Reduced needless internal loops. It improves phrase search performance. [GitHub#519] [Patch by Naoya Murakami]
- [How to contribute to groonga] Updated documentation about contribution. [GitHub#522] [Patch by Hiroshi Ohkubo]
- [Return code] Updated documentation about return code list.
- [groonga executable file] Added `--default-request-timeout` option.
- [windows] Supported DLL version.
- Supported index used search even if value only term exists. For example, `true || column > 0` doesn't use index even if `column` has index. In this release, above issue is resolved.
- [select] Supported specifying grouped table [GitHub#524,#526,#527,#528,#529] [Patch by Naoya Murakami]
- Supported grouping by `Int{8,16,64}/UInt{8,16,64}` value. In the previous versions, only 32bit fixed size value was supported.
- Added table name to error message for invalid sort key.
- [groonga-suggest-httpd] Updated documentation.
- [Completion] Fixed a typo about example. [groonga-dev,04008] [Reported by Tachikawa Hiroaki]
- [grndb] Added a workaround to keep backward compatibility. use `object_inspect` instead of `inspect`.
- [groonga-httpd] Updated bundled nginx version to 1.9.15.
- [centos] Supported systemd.
- [doc] Supported only HTML output. [GitHub#532] [Patch by Hiroshi Ohkubo]
- [groonga-httpd][centos] Supported to customize environment variables.
- [Others] Updated documentation about `--with-package-platorm` option.
- [ubuntu] Supported Ubuntu 16.04 (Xenial Xerus)

### Fixes

- Fixed a bug that tokenization of zero-length values are failed. For example, if `description` column is indexed column, tokenizer reports an error. [GitHub#508] [Reported by Naoya Murakami]:

      load --table docs
      [
      ["_key","description"],
      [2,""]
      ]

- Fixed a crash bug because of invalid critical section handling. [GitHub#507]

- [リリース手順] Fixed a typo about grntest howto. [GitHub#511] [Patch by Hiroshi Ohkubo]

- [doc] Removed man support.

- Removed invalid debug log messages which make user confused.

- Fixed a bug that data is not correctly flushed because internal counter is wrongly cleared. In the previous version, when size of data exceeds specific one, it was failed to create indexes. [GitHub#517] [Reported by Naoya Murakami]

- Fixed a bug that a process can't use more than one caches in parallel. [GitHub#515]

- Fixed a bug that internally used `alloc_info` structure which is used to find memory leaks is not exclusively accessed. Without this fix, it may causes a crash. [GitHub#523]

- [tokenizer mecab] Fixed a memory leak on dictionary encoding mismatch error. [groonga-dev,04012] [Reported by Naoya Murakami]

- Fixed a bug that combination of [groonga-suggest-httpd] and [groonga-suggest-learner] didn't work.

- [doc] Removed needless uuid from *.po [GitHub#531] [Patch by Hiroshi Ohkubo]

- [highlight_html] Fixed a bug that duplicated text is returned. This bug occurs when highlighted keyword occurred 1024 or more times.

- Fixed a bug that `KEY_LARGE` conflicts with existing flag. If you use `TABLE_HASH_KEY|KEY_LARGE` in the previous version, there is a possibility to break database. Please recreate the table.

### Thanks

- Naoya Murakami
- Hiroshi Ohkubo
- Tachikawa Hiroaki

## Release 6.0.1 - 2016-03-29

### Improvements

- [mruby] Updated bundled mruby to fix a crash bug related to GC and backtrace.

- Exported the following API

  - grn_expr_take_obj()
  - grn_request_canceler_cancel_all()
  - grn_obj_remove_dependent()
  - grn_obj_is_text_family_type()

- [hash] Supported 4GiB over total key size when `KEY_LARGE` flag is set to a table:

      table_create Users TABLE_HASH_KEY|KEY_LARGE ShortText

- [load] Supported Request ID when you specify input data as raw JSON instead of parameter value:

      POST /d/load?table=XXX&request_id=x

      load --table XXX --request_id x
      [
        ...
      ]

- [shutdown] Added `mode` argument to shutdown immediately. Use `shutdown --mode immediate` in such a purpose.

- [Mac OS X] Added a instruction to setup MeCab dictionary for Homebrew.

- [load] Supported to stop load when cancel is requested.

- [table_remove] Supported to remove dependent tables. Use `--dependent yes` for it.

- [logical_table_remove] Supported to remove dependent tables.

- [Windows] Supported memory debug mode on Windows.

- Supported to dump allocation information by status on memory debug mode

- [I18N] Added installation step for Sphinx.

- [experimental] Supported to split chunks in static indexing. Use `GRN_INDEX_CHUNK_SPLIT_ENABLE=yes` to enable it. [GitHub#479]

### Fixes

- [load] Fixed a crash bug when nonexistent column is specified. [GitHub#493]
- [load] Fixed a bug that load command does not return error code correctly. [GitHub#495]
- [load] Fixed a memory leak when parsing columns parameter in load command.
- [load] Fixed a bug that only the first array in `--values` is handled as a list of column names if `--columns` is not specified. [GitHub#497]
- [load] Fixed to check `--columns` more precisely [GitHub#496]
- Fixed a insufficient critical section handling for thread-safety.
- [column_create] Fixed a crash bug when failed to create a column.
- [table_remove] Fixed a crash bug to remove nonexistent table. [GitHub#504]
- Fixed a bug that offline index construction against `WITH_POSITION` + non-text `VECTOR` column ignores position.
- [grndb] Fixed a bug that cycle reference causes stack over flow.
- [deb] Dropped support for Ubuntu 15.04 (Vivid Vervet)

### Thanks

- YUKI Hiroshi

## Release 6.0.0 - 2016-02-29

### Improvements

- [grndb] Supported check against table specified as table domain in `--target` mode.

- [`grn_pat_fuzzy_search()`] Added a new API that provides fuzzy search feature by patricia trie. [GitHub#460][Patch by Naoya Murakami]

- [`functions/string`] Added a new plugin that provides string related functions. [GitHub#459][Patch by Naoya Murakami]

- [`string_length()`] Added a new function that returns the number of characters in the specified string. It's contained in `functions/string` plugin. [GitHub#459][Patch by Naoya Murakami]

- [`grn_table_fuzzy_search()`] Added a new DB API that provides fuzzy search feature. [GitHub#463][Patch by Naoya Murakami]

- [`GRN_OP_FUZZY`] Added a new operator. [GitHub#463][Patch by Naoya Murakami]

- [`grn_obj_search()`] Supported `GRN_OP_FUZZY` operator. [GitHub#463][Patch by Naoya Murakami]

- [`GRN_TABLE_FUZZY_SEARCH_WITH_TRANSPOSITION`] Added a flag for `grn_table_fuzzy_search()`. [GitHub#463][Patch by Naoya Murakami]

- [`GRN_TOKENIZE_ONLY`] Added a new tokenization mode that returns all tokens even if the token doesn't exist in lexicon. [GitHub#463][Patch by Naoya Murakami]

- [`grn_obj_type_to_string()`] Add a new function that stringify type ID such as `GRN_VOID` and `GRN_BULK`.

- [object_inspect] Added a new command that returns information of the target object.

- Supported compare operations against vector. If left hand side vector includes any element that satisfies `left_hand_side_element OP right_hand_side`, it returns true.

  Example:

      [1, 2, 3] < 2 # -> true because 1 is less than 2
      [1, 2, 3] > 4 # -> false because all elements are less than 4

- [`fuzzy_search()`] Added a new function that provides fuzzy search feature. [GitHub#464][Patch by Naoya Murakami]

- [edit_distance] Supported transposition flag. [GitHub#464][Patch by Naoya Murakami]

- Supported index search for `vector_column[2] == 29`.

- [`GRN_PLUGIN_CALLOC()`] Added a new API for plugin that provides `calloc()` feature. [GitHub#472][Patch by Naoya Murakami]

- Supported index search for compare operations against vector element such as `vector_column[2] < 29`.

- [`grn_plugin_proc_get_var_bool()`] Add a new API for plugin that provides getting boolean argument value feature.

- [`grn_plugin_proc_get_var_int32()`] Add a new API for plugin that provides getting 32bit integer argument value feature.

- [`grn_plugin_proc_get_var_string()`] Add a new API for plugin that provides getting string argument value feature.

- [object_remove] Added a new command that removes an object. `object_remove` can also remove a broken object.

- Supported mips/mipsel. [debian-bugs:770243][Reported by Nobuhiro Iwamatsu][Reported by Thorsten Glaser][Reported by YunQiang Su][Reported by Dejan Latinovic][Reported by Steve Langasek]

- [grndb][CMake] Supported.

- [`grn_expr_syntax_expand_query()`] Added a new API that provides query expansion feature.

- [`snippet()`] Add a new function that provides snippet feature. [GitHub#481][Patch by Naoya Murakami]

- [`highlight()`] Add a new function that provides highlight feature. [GitHub#487][Patch by Naoya Murakami]

- Added `XXX && column != xxx` optimization. It's converted to `XXX &! column == xxx` internally.

- [Memcached binary protocol] Added `--memcached-column`. You can access existing column by memcached protocol.

- [groonga-httpd] Supported TLS. [groonga-dev,03948][Reported by KITAITI Makoto]

- [groonga-httpd] Updated bundled nginx version to 1.9.11 from 1.9.10.

- [Windows][CMake] Supported LZ4. LZ4 is bundled.

### Fixes

- [select] Added a missing error check for outputting column. [GitHub#332][Reported by Masafumi Yokoyama]
- Fixed a bug that `function(column_with_index) == 29` ignores `function()`. [groonga-dev,03884][Reported by Naoya Murakami]
- [reindex] Fixed a bug that `reindex` doesn't clear query cache.
- [patricia trie] Fixed a bug that sorting by integer patricia trie key returns unsorted result. [GitHub#476][Reported by Ryunosuke SATO]
- [select] Fixed a crash bug that is occurred when too many keywords is specified into `--query`. [GitHub#484][Reported by Hiroyuki Sato]
- [select] Fixed a bug that wrong cache is used when Command version or Pretty print is used. [GitHub#490][Reported by KITAITI Makoto]

### Thanks

- Masafumi Yokoyama
- Naoya Murakami
- Nobuhiro Iwamatsu
- Thorsten Glaser
- YunQiang Su
- Dejan Latinovic
- Steve Langasek
- Ryunosuke SATO
- Hiroyuki Sato
- KITAITI Makoto

## Release 5.1.2 - 2016-01-29

### Improvements

- Improved performance for sequential search against constant value such as `true` and `29`.
- Improved performance for sequential search against binary operation with constant value such as `x == 29` and `x < 29`.
- [select] Changed score type to `Float` from `Int32` when Command version is 2. The current default command version is 1. Command version 2 is experimental. So this change isn't affected to normal users. [GitHub#450][Patch by Naoya Murakami]
- [grn_ts] Supported match operator.
- [grndb] Added `--target` option to `check` command. It reduces check target.
- [Windows] Updated bundled msgpack to 1.3.0 from 1.0.1.
- [Windows] Updated bundled MeCab to 0.996 from 0.98.
- [`grn_hash_size()`] Added a new API that returns the number of records in the hash table.
- [`GRN_HASH_TINY`] Added a new flag to create tiny hash table.
- [`grn_dump_table_create_flags()`] Added a new API that converts `flags` value of a table to `flags` parameter format of table_create.
- [`grn_dump_column_create_flags()`] Added a new API that converts `flags` value of a column to `flags` parameter format of column_create.
- [`grn_plugin_get_names()`] Added a new API that returns all plugin names in a database.
- [`grn_column_get_all_index_data()`] Added a new API that returns all index data for a table or data column.
- [schema] Added indexes information to indexed tables and data columns.
- [`grn_config_get()`] Renamed from `grn_conf_get()`.
- [`grn_config_set()`] Renamed from `grn_conf_set()`.
- [`grn_config_delete()`] Added a new API that deletes a configuration item.
- [config_set] Added a new command that sets a configuration item.
- [config_get] Added a new command that gets a configuration item value.
- [config_delete] Added a new command that deletes a configuration item.
- [`grn_config_cursor_open()`] Added a new API that opens a new cursor that iterates all configuration items.
- [`grn_config_cursor_next()`] Added a new API that moves to the next configuration item in the cursor.
- [`grn_config_cursor_get_key()`] Added a new API that gets the key of the current configuration item.
- [`grn_config_cursor_get_value()`] Added a new API that gets the value of the current configuration item.
- [Alias] Supported aliasing table and column names.
- [hash table] Added total key size overflow check.
- [dump] Supported dumping configurations set by config_set.
- [patricia trie] Improved inspection. [GitHub#452][GitHub#457][Patch by Naoya Murakami]
- [`grn_get_global_error_message()`] Added a new API that gets the current error message in the process.
- [lock_acquire] Added a new command that acquires a lock of a database, table or column.
- [lock_release] Added a new command that releases a lock of a database, table or column.
- [groonga-httpd] Updated bundled nginx version to 1.9.10 from 1.9.7.

### Fixes

- Fixed mruby related crash bugs.
- [Windows] Fixed label in installer. [groonga-dev,03825][Reported by Atsushi Shinoda]
- [doc] Fixed typos. [GitHub#456][GitHub#458][Patch by tSU_RooT]
- [Memcached binary protocol] Added more description. [GitHub#454][Patch by Hiroyuki Sato]
- Fixed a bug that Command version specified by `command_version` parameter in a request isn't reset.

### Thanks

- Naoya Murakami
- Atsushi Shinoda
- tSU_RooT
- Hiroyuki Sato

## Release 5.1.1 - 2015-12-29

### Improvements

- [Script syntax] Supported `INDEX_COLUMN == VALUE` as index search with an equal supported index.
- Reduced the continuous same messages from inverted index module.
- Supported detecting truncated tables by another process. [GitHub#447] [groonga-dev,03761] [Reported by Yutaro SHIMAMURA]
- [`grn_db_recover()`] Supported detecting a broken object.
- Improved performance for sequential scan search by Regular expression match with constant pattern such as `COLUMN @~ "CONSTANT_PATTERN"`.

### Fixes

- Fixed build error on MessagePack support build. [groonga-dev,03708] [Reported by Ryo Sugimoto]
- [mruby] Fixed a crash bug on error. mruby exception feature is disabled as workaround for now.
- [thread_limit] Fixed a bug that `thread_limit?max=1` may not reduce the number of current running threads to `1`.
- [thread_limit] Fixed a bug that `thread_limit?max=1` may not return.
- [Tuning] Fixed wrong `sysctl` argument. [GitHub#448] [Reported by Hiroyuki Sato]

### Thanks

- Ryo Sugimoto
- Yutaro SHIMAMURA
- Hiroyuki Sato

## Release 5.1.0 - 2015-11-29

### Improvements

- [patiricia trie] Added an error check for the max total key size. See Limitations about the max total key size.
- [grndb] Added a check for broken object. The check can detect a case that the object can't be opened.
- [`grn_obj_reindex()`] Added a new API that recreates existing indexes.
- [reindex] Added a new command that recreates existing indexes.
- [inverted index] Improved estimation precision for query.
- [logical_range_filter] Added fallback mode for sequential search. If sequential search checked many records but didn't find required the number of records, index search is used as fallback.
- [`grn_get_package_label()`] Added a new API that returns package label. It returns `Groonga`.
- [Groonga HTTP server] Added `Server: Groonga/VERSION` response header.
- [groonga-httpd] Improved performance by reusing `grn_ctx` object.
- [`grn_file_reader`] Added a new API that provides `fgets()` feature. It fixes a crash bug of groonga executable file. If groonga executable file is built with static C runtime by Visual Studio, the crash bug is occurred.
- [prefix_rk_search] Added a new selector that provides prefix RK search feature.
- [`grn_obj_is_accessor()`] Added a new predicate that checks whether the object is an accessor.
- [`grn_obj_is_key_accessor()`] Added a new predicate that checks whether the object is an accessor for `_key` Pseudo column.
- Supported Pretty print for JSON output.

### Fixes

- [inverted index] Fixed a possible infinite loop bug when log level is `debug`.
- Fixed a bug that `@` operator (match operator) may not match record that should be matched in sequential search mode.
- [patricia trie] Fixed a bug that invalid value may be returned for empty string key. [groonga-dev,03632] [Reported by Naoya Murakami]

### Thanks

- Naoya Murakami

## Release 5.0.9 - 2015-10-29

### Improvements

- [inverted index] Reduced log levels of logs for developers.
- Flushed pending changed on creating new database. It guards database from crash.
- [`grn_geo_table_sort()`] Added a new API that sorts table by geometry index.
- [experimental] Added expression rewrite mechanism. You can write custom expression rewriter by mruby. Expression rewriter can be used for optimizing an expression, changing conditions in an expression and so on.
- [experimental] Added database global configuration mechanism. You can put configurations (key and value pairs) into database. For example, it will be used in TokenFilterStopWord to custom column name from `is_stop_word`.
- [`grn_conf_set()`] Added a new API that sets a configuration.
- [`grn_conf_get()`] Added a new API that gets a configuration.
- [deb] Changed to `all` from `any` for `Architecture` value. [debian-bugs:799167][Reported by Matthias Klose]
- [Windows][CMake] Supported building bundled MeCab. [groonga-dev,03562][Reported by Sato]
- [schema] Added a new command that returns schema. Schema is consists with loaded plugins, loaded tokenizers, loaded normalizers, loaded token filters, defined tables and defined columns.
- [`grn_plugin_win32_base_dir()`] Deprecated. Use `grn_plugin_windows_base_dir()` instead.
- [`grn_plugin_windows_base_dir()`] Renamed from `grn_plugin_win32_base_dir()`.
- [`grn_obj_is_type()`] Add a new API that returns true when the passed object is a type object.
- [`grn_obj_is_tokenizer_proc()`] Add a new API that returns true when the passed object is a tokenizer object.
- [`grn_obj_is_normalizer_proc()`] Add a new API that returns true when the passed object is a normalizer object.
- [`grn_obj_is_token_filter_proc()`] Add a new API that returns true when the passed object is a token filter object.
- [`grn_ctx_get_all_types()`] Add a new API that returns all type objects in database.
- [`grn_ctx_get_all_tokenizers()`] Add a new API that returns all tokenizer objects in database.
- [`grn_ctx_get_all_normalizers()`] Add a new API that returns all normalizer objects in database.
- [`grn_ctx_get_all_token_filters()`] Add a new API that returns all token filter objects in database.
- [`grn_ctx_output_uint64()`] Add a new API that outputs 64bit unsigned integer value.
- [`grn_ctx_output_null()`] Add a new API that outputs `NULL`.
- [`GRN_OBJ_IS_TRUE()`] Add a new API that returns true when the passed object is true value.
- [experimental] Enabled grn_ts by default.
- [Ubuntu] Added Ubuntu 15.10 Wily Werewolf support.

### Fixes

- [patricia trie] Fixed a bug that the number of records may be counted up unexpectedly on adding a new entry. [GitHub#417]
- [patricia trie] Fixed a bug that a variable may be used uninitialized.
- [patricia trie] Fixed a bug that `grn_pat_cursor_next()` may enter an infinite loop. [GitHub#419]
- [patricia trie] Fixed a bug that deleting an entry may break patricia trie. [GitHub#415][groonga-dev,03515][Reported by Hiroshi Kagami]
- [patricia trie] Fixed a bug that deleting a nonexistent entry may break patricia trie. [GitHub#420]
- Fixed a bug that wrong proc type is used for token filter objects.

### Thanks

- Matthias Klose
- Hiroshi Kagami
- Sato

## Release 5.0.8 - 2015-09-29

### Improvements

- [Windows] Supported build with MySQL again.

- [Script syntax] Changed return value type to `Bool` from `Int32` for predicate operations such as Match operator and Equal operator.

- [API] Supported owning other `grn_obj` by `GRN_PTR` and `GRN_PVECTOR` bulk. If you specify `GRN_OBJ_OWN` flag to `GRN_PTR` and `GRN_PVECTOR` bulks, they call `grn_obj_close()` against `grn_obj` that is held by them when they are closed.

- [incompatible][Regular expression] Changed to normalize regular expression match target text before matching. It's for consistency and performance.

  Other operations such as Prefix search operator normalize target text.

  Some simple regular expressions such as `\Ahello` can be evaluated by index. It's fast.

  If target text isn't normalized, you need to use complex regular expressions such as `\A[Hh]ello` and `\A(?i)hello`. Complex regular expressions can't be evaluated by index. If target text is normalized, you can use simple regular expressions. They may be evaluated by index. It's fast.

- [doc] Improved documents. [GitHub#393][GitHub#396][GitHub#397][GitHub#399][GitHub#403] [GitHub#405][GitHub#409] [Reported by Hiroyuki Sato][Patch by Hiroyuki Sato]

- [highlight_html] Improved performance. [groonga-dev,03427] [Reported by Hiroyuki Sato]

- [snippet_html] Improved performance.

- [CMake] Stopped to run `pkg-config` twice. [Patch by Sergei Golubchik]

- Removed needless check for year in time. B.C. is always invalid time without this change. B.C. is valid time when system (`mktime()`) supports it with this change.

- [`grn_ctx_is_opened()`] Added a new API that checks whether object with the ID is opened or not.

- [`grn_obj_remove()`] Reduced the maximum memory usage. If `grn_thread_get_limit()` returns `1`, it closes temporary opened objects after it finished to use them.

- [doc][table_remove] Updated with many descriptions.

- [groonga executable file] Ensured to add the last new line to dump result on stand alone mode.

- [Process log] Added Groonga version into `grn_init` log.

- Opened chat room on Gitter.

- [status] Added `start_time` as alias of `starttime` for consistency. Other keys use `snake_case` style. `starttime` is deprecated. Use `start_time` instead.

- Updated bundled Onigmo.

- [doc][scorer_tf_at_most] Documented.

- Supported columns for temporary table. It's only available C API users for now. select will use this feature in the next release.

- [`grn_vector_pop_element()`] Exported.

- [groonga executable file] Added checks whether acquiring lock is succeeded or not.

- [groonga-suggest-create-dataset] Changed to use `--normalizer` instead of `KEY_NORMALIZE` because `KEY_NORMALIZE` is deprecated.

- [`grn_obj_cast()`] Exported.

- [experimental][`grn_ii_cursor`] Exported.

- [experimental][`grn_ii_cursor_open()`] Exported.

- [experimental][`grn_ii_cursor_next()`] Exported.

- [experimental][`grn_ii_cursor_close()`] Exported.

- [Match operator] Improved index detection. Index its lexicon has a tokenizer is preferred.

- [groonga-httpd] Updated bundled nginx to 1.9.5 that supports HTTP/2. HTTP/2 module is enabled.

### Fixes

- [Script syntax] Fixed a bug that `&!` does nothing when right hand side is `true`.
- Fixed performance regression with libtool 2.4.6. [GitHub#406][GitHub#407] [Patch by Hiroyuki Sato]
- [Equal operator] Fixed a bug that section is ignored.

### Thanks

- Hiroyuki Sato
- Sergei Golubchik

## Release 5.0.7 - 2015-08-31

This release includes a bug fix of Offline index construction.

If you're using any multiple column index (index column with `WITH_SECTION` flag) and Offline index construction, we recommend that you upgrade your Groonga.

This release has an important experimental feature for Windows users. See "sparse file support" entry in the following improvement list for details.

### Improvements

- [experimental][Windows] Added sparse file support. It's experimental feature. It's disabled by default. You can enable it by specifying `GRN_IO_USE_SPARSE=yes` environment variable.

  It reduces database file size on Windows. Please try the feature and report the result. Groonga developers are interested in the followings:

  - Disk usage
  - Performance (Improved? Degraded? No difference?)
  - Memory usage (Especially virtual memory usage)

- [experimental][logical_shard_list] Added a command that returns a shard list of the specified logical table.

- [experimental][Regular expression operator] Supported regular expression match against vector column without index.

- [logical_range_filter] Supported `--cache no` option. It's same as cache option in select.

- [groonga-httpd] Supported returning the max number of threads feature of thread_limit. You can't set the max number of threads.

- [`grn_db_unmap()`] Added a new API that unmaps all opened tables and columns. It's a thread unsafe operation. You can't touch the database while `grn_db_unmap()` is running.

- [database_unmap] Added a command that unmaps all opened tables and columns in database.

- [object_exist] Added a command that checks whether object with the specified name exists or not in database.

- [column_copy] Added a command that copies all values from source column to destination column.

  You can use this command to change column value type, column type, table type and so on.

- Stopped to use non-standard `__uint32_t` type. [GitHub#375][Reported by Natanael Copa]

- [experimental][Windows] Supported Windows Event log.

- [mruby] Supported error handling on mruby initialization error.

- [experimental][thread_limit] Renamed from `thread_count`.

- Supported logging used indexes in `info` level and `debug` level. It can be used like `EXPLAIN` in RDBMS. It's useful to improve slow query.

- [doc] Replaced deprecated `KEY_NORMALIZE` flags. [GitHub#378][GitHub#380][GitHub#382] [Patch by Hiroyuki Sato]

- [doc] Removed needless Sphinx configurations. [GitHub#379] [Patch by Ayumu Osanai]

- [experimental][incompatible][Regular expression operator] Changed `.` match behavior. `.` matches new line. It's backward incompatible change.

- [doc][How to build Groonga at the repository] Added a document about building Groonga as Groonga developer. [GitHub#353] [Suggested by Hiro Yoshioka]

### Fixes

- [mruby] Fixed a time overflow bug.

- [groonga executable file] Fixed a crash bug when PID file can't be created. [GitHub#368] [Reported by Hiroyuki Sato]

- Fixed a bug that Offline index construction may generate broken index. It may be caused for multiple column index. In other words, index column with `WITH_SECTION` flag may be broken.

  If you're using Online index construction for index columns with `WITH_SECTION` flag, this bug isn't affected.

  You can recover this bug by recreating existing multiple column indexes.

- [query] Fixed a crash bug when query is used in scorer.

- [filter] Fixed a bug that Bitwise NOT operator against unsigned int value doesn't work for comparing to `-NUMBER_LITERAL`.

  For example, the following expression doesn't work:

      ~UINT32_COLUMN == -6

- Fixed a bug that Regular expression operator doesn't work in multithread.

- Fixed some memory leaks.

- Fixed a build error. [GitHub#381] [Patch by Hiroshi Hatake]

### Thanks

- Hiroyuki Sato
- Natanael Copa
- Ayumu Osanai
- Hiroshi Hatake
- Hiro Yoshioka

## Release 5.0.6 - 2015-07-29

### Improvements

- [Ubuntu] Dropped Ubuntu 14.10 (Utopic Unicorn) support. It had been End of Life on July 23, 2015.

- Supported offline index construction for reference vector. For example, `load` data before `column_create` an index:

      table_create Entries TABLE_NO_KEY
      column_create Entries numbers COLUMN_VECTOR Int32

      load --table Entries
      [
      ["numbers"],
      [[18, 19, 20]],
      [[100, 200]]
      ]

      table_create Numbers TABLE_PAT_KEY Int32
      column_create Numbers entries_numbers COLUMN_INDEX Entries numbers

      select Numbers --output_columns _key

- Supported `'vector_text_column @ "element"'` without index. For example, the `select` command in the following commands:

      table_create Memos TABLE_NO_KEY
      column_create Memos tags COLUMN_VECTOR Text

      load --table Memos
      [
      {"tags": ["Groonga", "Rroonga", "Mroonga"]}
      ]

      select Memos --filter 'tags @ "Rroonga"'

- Supported `'fixed_size_type_vector_column @ n'` without index. For example, the `select` command in the following commands:

      table_create Memos TABLE_NO_KEY
      column_create Memos numbers COLUMN_VECTOR Int32

      load --table Memos
      [
      {"numbers": [1, 2, 3]}
      ]

      select Memos --filter 'numbers @ 2'

- [CentOS][Server packages][groonga-httpd] Show exit status. [GitHub#357] [Patch by jacob16bit]

- [Windows][groonga executable file] Supported `--pid-path`.

- [Windows] Allowed to delete file that is opened by other process.

- Accepted selector only proc. Note that the proc can't be used as function. It means that the proc can't be used with sequential search.

- Supported function call with complex argument. An example complex argument is `Table["key"].column`. For example:

      function(_key, Table["key"].column)

- [doc][Tutorial] Added more description about database creation fails if DB_PATH points to an existing file. [GitHub#354] [Suggested by Hirotaka Takayama]

- [doc][Tutorial] Described JSON formatting tools. [GitHub#355] [Suggested by tiwawan]

- [experimental] Added an API to get/set the number of threads. It's a experimental API.

- [experimental][`thread_count`] Added a command that get/set the number of threads. It's a experimental command.

- [experimental][groonga executable file] Supported changing the number of threads by `thread_count` command. It's a experimental feature.

- [experimental][Windows] Added Windows event log support. It's a experimental feature.

- [experimental][groonga executable file] Added Windows event log related option `--use-windows-event-log`. It reports logs as Windows events. It's a experimental feature.

- [Windows] Used Groonga's default encoding for log message.

- Log used indexes in `INFO` level. The default level `NOTICE`. So the logs aren't showed by default.

- [API] Added `grn_log_level_to_string()` and `grn_log_level_parse()`.

- [groonga executable file] Accepted log level name (e.g. `info`, `debug` and so on) for `--log-level` value.

- [log_level][log_put] Accepted log level name for `--level` argument.

- [plugin] Added `grn_command_input_get_arguments()`.

- Updated sharding plugins.

  - [logical_select] Fixed output format. It has become select compatible format.
  - [logical_select] Supported the following parameters.
    - `--output_columns`
    - `--offset`
    - `--limit`
    - `--drilldown`
    - `--drilldown_sortby`
    - `--drilldown_offset`
    - `--drilldown_limit`
  - [logical_select] Used the same default output_columns (`"_id, _key, *"`) as select.
  - [logical_select] Supported drilldown[${LABEL}].calc_types and drilldown[${LABEL}].calc_target for labeled drilldown.
  - [logical_select] Supported cache.
  - [logical_count] Supported logging whether range index is used or not.
  - [logical_count] Show target table name in debug log.
  - [logical_count] Supported cache.
  - [logical_range_filter] Supported `'fixed_size_type_vector_column @ element'`.
  - [logical_range_filter] Added `use_range_index` parameter. It's a parameter for test. It should not be used for production.
  - [logical_range_filter] Log which mode (range-index or select mode) is used.
  - [logical_range_filter] Supported cache.
  - [logical_range_filter] Supported nested reference vector accessor.
  - [logical_range_filter] Used range_index value set by logical_parameters.
  - [logical_parameters] Added.

- Added mruby APIs.

  - [mrb] Added `Accessor#name`.
  - [mrb] Added `Column#[]`.
  - [mrb] Added `Column#scalar?`, `Column#vector?` and `Column#index?`.
  - [mrb] Added `Context#command_version` and `Context#command_version=` (accessors).
  - [mrb] Added `Context#with_command_version`.
  - [mrb] Added `Database#each_name`.
  - [mrb] Added `Groonga::Cache.current`.
  - [mrb] Added `Record`.
  - [mrb] Added `Table#each`.
  - [mrb] Added `TableCursor#key`.
  - [mrb] Binded `grn_command_input_get_arguments()` to `CommandInput#arguments`.
  - [mrb] Binded `grn_table_group()` to `Table#group`.
  - [mrb] Binded `grn_table_group_flags()` to `TableGroupFlags`.
  - [mrb] Binded `GRN_COMMAND_VERSION_DEFAULT`.
  - [mrb] Binded `grn_cache`.
  - [mrb][estimate_size] Supported `(... || ...) && (... || ...)` as expression case.
  - [mrb] Supported query log.

### Fixes

- Fixed a memory leak when an error is occurred in `grn_expr_exec()`. For example, unsupported operator (e.g. `GRN_OP_TERM_EXTRACT`) is used (`not implemented operator assigned` is occurred for the case).

- [bindings/php] Added a missing check for a memory allocation failure. [Reported by Bill Parker]

- [CentOS][Server packages][logrotate] Fixed syntax error in script.

- [CentOS][Server packages][logrotate] Fixed wrong daemon running check.

- [CentOS][Server packages][logrotate] Stop to set owner/group to log files. Because it's not consistent. groonga-httpd creates log files with root owner/group. But logrotated log files are created with groonga owner/group. [GitHub#358] [Reported by jacob16bit]

- [groonga executable file] Fixed reported the maximum number of threads.

- [groonga-httpd] Remove a needless space in log message:

      |n|  grn_fin (0) ->
      |n| grn_fin (0)
          ^

- Fixed a bug that estimating size by regexp query with anchor (e.g. `\\\\A` in `--filter 'comment @~ "\\\\Abc"'`) doesn't work. The feature is used in logical_range_filter.

- [Request ID] Fixed a memory leak when `request_id` byte size >= 24.

- [lock_clear] Fixed a typo in command name in Syntax section. [GitHub#363] [Reported by Christian Kakesa]

- [sharding] Fixed wrong min include detection for month range type.

### Thanks

- Bill Parker
- jacob16bit
- Hirotaka Takayama
- tiwawan
- Christian Kakesa

## Release 5.0.5 - 2015-06-29

### Improvements

- Show correct error information such as NoSuchFileOrDirectory when opening a database.

- Don't set the default logger path for library use.

  - It's backward incompatible change. But it will not effect to many users.
  - Server use (groonga command, Mroonga, PGroonga and so on) users can get log by default. In server use, developers set up log in their software.
  - Most library use (Rroonga, groonga-gobject and so on) users couldn't get log by default with earlier versions. The default log path is system path such as /var/log/groonga/groonga.log. It's not writable for normal users.

- [windows] Show error information when memory isn't enough on failing `CreateFileMapping()`.

- [tokenize] Updated example to show new "force_prefix" value. This value is added since 5.0.4.

- [windows] Show error information when disk has any problem (disk full and so on) on failing `FlushViewOfFile()`.

- [API] Added `grn_obj_flush()`.

- [API] Added `grn_obj_flush_recursive()`.

- [io_flush] Added. It flushes memory mapped data to disk. Usually memory data automatically flush by an OS, but you can explicitly flush with this command.

- [mruby] Binded `grn_obj_remove()` to Object#remove.

- [mruby] Binded `grn_table_delete()` and `grn_table_delete_by_id()` to Table#delete.

- [logical_table_remove] Added.

- [logical_select] Added. `--filter` is only supported for now.

- [cmake] Supported embedded MeCab tokenizer.

- [logical_count] Supported month and day mixed shards. In the same month, month shard must have earlier records rather than day shards in the same month. For example:

      XXX_201506   <- includes only 2015-06-01 and 2015-06-02 records
      XXX_20150603 <- includes only 2015-06-03 records
      XXX_20150604 <- includes only 2015-06-04 records

### Fixes

- Fixed wrong macro to include netinet/in.h. [GitHub#348] [Reported by OBATA Akio]
- [rpm][groonga-httpd] Fixed failing restart. [GitHub#351] [Patch by jacob16bit]

### Thanks

- OBATA Akio
- jacob16bit

## Release 5.0.4 - 2015-05-29

### Improvements

- [mruby] Changed to use `inspect` to show meaningful error message for error value.
- [mruby] Supported `Groonga::Bulk#inspect` to inspect bulk content.
- [mruby] Supported `Bulk#value` to extract the value of record from bulk content.
- [mruby] Supported estimating size for `reference_column == record_id` in logical_range_filter. In above case, it can be searched more effectively.
- [sub_filter] Supported index column as `scope` parameter.
- [Script syntax] Described clearly about numerical value. [GitHub groonga/groonga.org#16] [Suggested by Hiroyuki Sato]
- [select] Supported accessing other table's record in filter. You can use `--filter 'OTHER_TABLE[KEY].COLUMN'` for example.
- [select] Supported operator in table key. You can use `--filter 'OTHER_TABLE["SOME STRING" + "ANOTHER STRING"].COLUMN'"` for example.
- [example] Used Ruby 2.0 or later API in script for converting dictionary data.
- Changed to show error message about invalid type of keys about table.
- [doc] Fixed link from sourceforge.jp to osdn.me or osdn.jp about mailing list preference page. SourceForge.jp is marked as obsoleted because of branding issue since May 11, 2015.
- [tokenize] Added `force_prefix` value to each token information. [Patch by Naoya Murakami]
- Supported to search by shorter words such as 2 or less characters for TokenTrigram. [Patch by Naoya Murakami]
- [deb] Added service file for Systemd into groonga-httpd and groonga-server-gqtp packages.
- [select] Ignored `--query` when its value consists of only space characters. Space characters include full-width space (`U+3000 IDEOGRAPHIC SPACE` in Unicode). [Suggested by TomyGX]

### Fixes

- Fixed a crash bug when empty key is specified for `drilldown[label].keys`.
- Fixed a bug that the return value of `grn_parse_query_flags` is not properly checked. [GitHub#336] [Reported by Hiroaki Nakamura]
- Fixed a build error on some BSD systems. They doesn't have `-i` option for `sed`.
- Fixed a build error on Solaris. It is changed to initialize by `sizeof(msghdr)` in `memset()` because `msg_control`, `msg_controllen` and `msg_flags` doesn't exist on Solaris by default.
- [Tokenizers] Fixed a typo. [GitHub#338] [Reported by Hiroyuki Sato]
- [Output] Fixed markup. [GitHub groonga/groonga.org#17] [Reported by Hiroyuki Sato]
- Reduced getenv() in each `grn_ii_cursor_set_min()`. This fixes performance regression on Windows.
- Fixed a build error on OpenBSD. [groonga-dev,03255] [Reported by fbnteqr]
- [groonga-httpd] Fixed a bug that same message is logged.
- Fixed a crash bug which is caused by double free memory.
- Fixed a memory leak. It's occurred when `--match_columns` and `--query` are used for non indexed text field and text fields have a value that isn't bulk embeddable. Normally, 32byte over size text isn't bulk embeddable, so this bug doesn't affect to the case if only small text less than 32byte are stored.
- [Tokenizers] [TokenRegexp] Fixed a bug that it can't be searched correctly when query contains characters which are treated as blank character. For example, the newline - "\n" is typical one.

### Thanks

- Hiroaki Nakamura
- Hiroyuki Sato
- Naoya Murakami
- fbnteqr
- TomyGX

## Release 5.0.3 - 2015-04-29

### Improvements

- [Tokenizers][Regular expression] Skip the last one character token.
- [mruby] Supported regexp pattern for estimating size.
- [mruby] Supported size estimation for accessor.
- [logical_range_filter] Removed `GRN_LOGICAL_RANGE_FILTER_ENABLED` environment variable which is introduced since Groonga 5.0.2. Use `GRN_LOGICAL_RANGE_FILTER_THRESHOLD=0` to disable range index search feature.
- [logical_range_filter] Supported negative limit and offset.
- [Windows] Used Groonga Admin in package.
- [logical_range_filter] Changed threshold meaning:
  - threshold <= 0.0: always use range index
  - threshold >= 1.0: never use range index
- [dump] Supported plugin.
- [dump] Added the following options:
  - `--dump_plugins [yes(default)/no]`
  - `--dump_schema [yes(default)/no]`
  - `--dump_records [yes(default)/no]`
  - `--dump_indexes [yes(default)/no]`
- [API] Added `grn_plugin_get_ruby_suffix()`.
- [dump] Fixed order to put index columns after reference columns because index column may refer reference columns.
- [dump] Don't dump records of lexicon.
- [dump] Show `_id` for `TABLE_NO_KEY` again.
- [dump] Used offline index construnction.
- Increased max hash key size from 4KiB (4096Byte) to 64KiB - 1 (65535Byte).
- Increased max cache key size from 4KiB (4096Byte) to 64KiB - 1 (65535Byte).
- Improved performance for nested index search.
- Used index for nonexistent reference column value.
- [experimental] Added plugin functions/vector. It includes vector_size function.
- [Windows] Updated Visual Studio version [GitHub groonga/meetup#4] [Reported by Hiroyuki Mizuhara]
- [cache_limit] Expired old caches when the max N caches is decreased. [Suggested by Gurunavi, Inc.]
- Show more information such as errno for errors.
- [windows] Used secure functions on Windows.
- Added the following APIs to change log rotate threshold in file size.
  - `grn_default_logger_set_rotate_threshold_size()`
  - `grn_default_logger_get_rotate_threshold_size()`
  - `grn_default_query_logger_set_rotate_threshold_size()`
  - `grn_default_query_logger_get_rotate_threshold_size()`
- [experimental] Supported log rotation. The feature is disabled by default. You can enable log rotation by the following options:
  - `--log-rotate-threshold-size`
  - `--query-log-rotate-threshold-size`
- [GQTP] Documented about GQTP server.
- [groonga executable file] Documented groonga executable file partially.
- Supported Ubuntu 15.04 (Vivid Vervet).
- Supported Debian 8.0 (Jessie).
- [groonga-httpd] Updated bundled nginx version to the latest mainline (1.8.0).

### Fixes

- [windows] Fixed a bug that Offline index construction is failed for large data (at least 1GB or larger) with Groonga built by Microsoft Visual C++. [Reported by Hideki ARAI]
- [mruby] Made `\\` index searchable in regular expression.
- Fixed a bug that `GRN_II_CURSOR_SET_MIN_ENABLE=yes` doesn't return some matched records.
- [sharding] Fixed a bug that partial range is handled as all range.
- [logical_range_filter] Fixed a bug that `:order => "descending"` doesn't work.
- [logical_count] Re-supported counting with range index.
- Fixed a bug causing malfunction of `grn_pat_del()` and added a test for invalid patricia trie node add case. [groonga-dev,03177] [Reported by yuya sako]

### Thanks

- Hideki ARAI
- Hiroyuki Mizuhara
- Gurunavi, Inc.
- yuya sako

## Release 5.0.2 - 2015-03-31

It's a bug fix release of 5.0.1.

### Improvements

- Supported MessagePack 1.0.1. [Reported by Hiroshi Hatake]
- [logical_range_filter] Disabled range index by default. It's enabled when you set the enviromnent variable `GRN_LOGICAL_RANGE_FILTER_ENABLED` to `yes`.

### Fixes

- Fixed a regression bug that JSONP doesn't work. It was introduced in Groonga 4.1.1.
- [windows] Fixed a bug that crash on x86 for Groonga 5.0.1. [groonga-dev,03131] [Reported by Atsushi Shinoda]
- Fixed a crash bug that libedit is not properly initialized. The problem is fixed in the environment such as CentOS 7.

### Thanks

- Atsushi Shinoda
- Hiroshi Hatake

## Release 5.0.1 - 2015-03-29

### Improvements

- [logical_range_filter] Supported filter and sort.

- Supported range search by multiple column index.

- Added API Overview document for users who want to use Groonga as library.

- [incompatible] Changed internal type of `_score` to floating point number from 32bit integer number. This is incompatible change for DB API users. This isn't incompatible change for query API users. It means that users who just use select aren't affected. Use the following code that works with both older and newer Groonga:

      grn_obj *score;
      double score_value;

      if (score->header.domain == GRN_DB_FLOAT) {
        score_value = GRN_FLOAT_VALUE(score);
      } else {
        score_value = (double)GRN_INT32_VALUE_FLOAT_VALUE(score);
      }

- [select] Added more strict check for invalid drilldown parameter.

- Added `grn_ctx_get_all_tables()`. [Suggested by Masatoshi Teruya]

- Supported to customize score function. See Scorer for details.

- [incompatible] Custom score function feature introduced API and ABI incompatibilities in DB API layer. If you're using `grn_search_optarg`, please check that your code initializes your `grn_search_optarg` by `0` like the following:

      grn_search_optarg options;
      memset(&options, 0, sizeof(grn_search_optarg));

  If your code do the above thing, your code is API compatible and ABI incompatible. You just need to rebuild your code without modification.

  If your code doesn't the above thing, you need to added the above thing to your code.

- Added the following predicates that check `grn_obj` type to DB API:

  - `grn_obj_is_table()`
  - `grn_obj_is_proc_proc()`
  - `grn_obj_is_function_proc()`
  - `grn_obj_is_selector_proc()`
  - `grn_obj_is_scorer_proc()`

- [experimental] Supported skipping posting list when searching popular term and rare term at the same time. It will improve performance. Set `GRN_II_CURSOR_SET_MIN_ENABLE` environment variable to `1` to enable the feature. The feature is disabled by default.

- [doc] Added in_values document.

- [doc] Added logical_count document.

- [mruby] Implemented custom `#inspect` method. Is is useful for debugging.

- Added scorer_tf_at_most scorer. It limits not to exceed specified score regardless of term frequency.

- [mruby] Supported estimating matched records for selecting index search or sequential search.

- Added the following functions to estimate size by index:

  - `grn_expr_estimate_size()`
  - `grn_ii_estimate_size_for_query()`
  - `grn_ii_estimate_size_for_lexicon_cursor()`

- Added missing NormalizerAuto availability check. [GitHub#283] [Reported by Tasuku SUENAGA]

- Dropped Visual Studio 2010 support.

- [experimental][mecab] Supported chunked tokenization. This feature is a workaround for MeCab's "too long sentense" error. Specify `yes` to `GRN_MECAB_CHUNKED_TOKENIZE_ENABLED` environment variable to enable it. By this configuration, Groonga splits a long text (8192 bytes over text by default) into small chunks and passes each chunk to MeCab. By this process, the above error isn't occurred. Additionally, you can customize chunk threshold bytes by `GRN_MECAB_CHUNK_SIZE_THRESHOLD` environment variable. Note that `,`, `.`, `!`, `?`, `U+3001 IDEOGRAPHIC COMMA`, `U+3002 IDEOGRAPHIC FULL STOP`, `U+FF01 FULLWIDTH EXCLAMATION MARK` and `U+FF1F FULLWIDTH QUESTION MARK` are treated as chunk delimiter characters.

- Supported `--pid-file` in server mode of groonga executable file.

- [groonga-httpd] Supported graceful stop to clean Groonga. It doesn't terminate the open connections immediately.

- [experimental] Supported regular expression. See Regular expression to know about how to use regular expression.

- [experimental] Added plugin_unregister command.

- [http][load] Added "," as chunk separator in POST data. It decreases internal buffer size and improves load time when POST data don't include any new line.

- [doc] Added Tokenizers document.

- Improved POSIX.2 compatibility by using `.` as bash's "source" command replacement. [GitHub#317] [Patch by Jun Kuriyama]

- [windows] Changed to the default IO version 1. It reduces disk usage on Windows. [groonga-dev,03118] [Tested by ongaeshi]

- [httpd] Updated bundled nginx version to the latest mainline (1.7.11).

- Changed mime-type for TSV output to `text/tab-separated-values` from `text/plain`.

- [TokenFilterStopWord] Supported Offline index construction. [GitHub#296] [Patch by Naoya Murakami]

### Fixes

- Fixed not to use obsolete `--address` parameter in the default groonga.conf. `--bind-address` is used instead. [Groonga-talk] [Reported by Dewangga]
- [truncate] Fixed a bug that TABLE_NO_KEY table can't be truncated.
- [mecab] Reduced needless logs for "empty token" and "ignore empty token".
- Fixed a bug that wrong section in index is used. It means that wrong search result is returned. If you satisfy all of the following conditions, this bug is occurred:
  - Multiple indexes are available.
  - The first defined index or the last defined index are multi-column indexes.
  - When both of the first defined index and the last defined index are multi-column indexes, source column orders are different in them.
- Fixed a bug that passing Groonga command line to groonga executable file from shell command line style usage always returns `0` as exit code. For example, `groonga DB_PATH nonexistent_command` always returned `0` as exist code.
- Fixed a bug that plugin path may be broken when two or more plugins registered. [Reported by Naoya Murakami]
- Fixed a bug that `Lexicon.index.source_column_name` style in match_columns doesn't work when source column specified by `source_column_name` has two or more indexes. [Reported by Naoya Murakami]

### Thanks

- Masatoshi Teruya
- Tasuku SUENAGA
- Dewangga
- Jun Kuriyama
- ongaeshi
- Naoya Murakami

## Release 5.0.0 - 2015-02-09

- Bump version to 5.0.0!

### Improvements

- [doc] Added Security about Script syntax.
- [experimental] Added sharding plugin. Execute register sharding to enable this feature in advance, then use logical_count to get the number of records.
- [cmake] Supported embedded Groonga with Clang. It fixed compilation failure on FreeBSD 10.1. [MDEV-7293] [Reported by Bernard Spil]
- Supported to customize plugins directory. Set GRN_PLUGINS_DIR environment variable.

### Fixes

- Fixed build failure when system has an incompatible version of onigmo/oniguruma headers installed. [GitHub#276] [Patch by Akinori MUSHA]
- Fixed time related build failure on MSVC [GitHub#237]

### Thanks

- Akinori MUSHA
- Bernard Spil

## The old releases

- Release 4.1.1 - 2015-01-29
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- Release 4.1.0 - 2015-01-09
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- Release 1.2.2 - 2011-05-29
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- 1.2.1リリース - 2011-04-29
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- 1.2.0リリース - 2011-03-29
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- バージョン1.1.xのお知らせ
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  - 1.0.3リリース - 2010-10-29
  - 1.0.2リリース - 2010-09-09
  - 1.0.1リリース - 2010-09-06
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- バージョン0.xのお知らせ
  - 0.7.7リリース - 2010-08-25
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- News in Senna period
  - Senna -> groonga - 2009-01-14
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