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

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# 7.3.34. `logical_select`

## 7.3.34.1. Summary

New in version 5.0.5.

`logical_select` is a sharding version of select. `logical_select` searches records from multiple tables and outputs them.

You need to plugin_register `sharding` plugin because `logical_select` is included in `sharding` plugin.

## 7.3.34.2. Syntax

This command takes many parameters.

The required parameters are `logical_table` and `shard_key`. Other parameters are optional:

    logical_select logical_table
                   shard_key
                   [min=null]
                   [min_border="include"]
                   [max=null]
                   [max_border="include"]
                   [filter=null]
                   [sortby=null]
                   [output_columns="_id, _key, *"]
                   [offset=0]
                   [limit=10]
                   [drilldown=null]
                   [drilldown_sortby=null]
                   [drilldown_output_columns="_key, _nsubrecs"]
                   [drilldown_offset=0]
                   [drilldown_limit=10]
                   [drilldown_calc_types=NONE]
                   [drilldown_calc_target=null]

`logical_select` has the following named parameters for advanced drilldown:

> - `drilldown[${LABEL}].keys=null`
> - `drilldown[${LABEL}].sortby=null`
> - `drilldown[${LABEL}].output_columns="_key, _nsubrecs"`
> - `drilldown[${LABEL}].offset=0`
> - `drilldown[${LABEL}].limit=10`
> - `drilldown[${LABEL}].calc_types=NONE`
> - `drilldown[${LABEL}].calc_target=null`

You can use one or more alphabets, digits, `_` and `.` for `${LABEL}`. For example, `parent.sub1` is a valid `${LABEL}`.

Parameters that have the same `${LABEL}` are grouped.

For example, the following parameters specify one drilldown:

> - `--drilldown[label].keys column`
> - `--drilldown[label].sortby -_nsubrecs`

The following parameters specify two drilldowns:

> - `--drilldown[label1].keys column1`
> - `--drilldown[label1].sortby -_nsubrecs`
> - `--drilldown[label2].keys column2`
> - `--drilldown[label2].sortby _key`

## 7.3.34.3. Differences from `select`

Most of `logical_select` features can be used like corresponding select features. For example, parameter name is same, output format is same and so on.

But there are some differences from select:

> - `logical_table` and `shard_key` parameters are required instead of `table` parameter.
> - `sortby` isn't supported when multiple shards are used. (Only one shard is used, they are supported.)
> - `_value.${KEY_NAME}` in `drilldown[${LABEL}].sortby` doesn't work with multiple shards. It works with one shard. `_key` in `drilldown[${LABEL}].sortby` work with multiple shards.
> - `match_columns` and `query` aren't supported yet.
> - `cache` isn't supported yet.
> - `match_escalation_threshold` isn't supported yet.
> - `query_flags` isn't supported yet.
> - `query_expander` isn't supported yet.
> - `adjuster` isn't supported yet.

## 7.3.34.4. Usage

Let's learn about `logical_select` usage with examples. This section shows many popular usages.

You need to register `sharding` plugin because `logical_select` is included in `sharding` plugin.

Execution example:

    plugin_register sharding
    # [[0, 1337566253.89858, 0.000355720520019531], true]

Here are a schema definition and sample data to show usage.

Execution example:

    table_create Entries_20150708 TABLE_HASH_KEY ShortText
    # [[0, 1337566253.89858, 0.000355720520019531], true]
    column_create Entries_20150708 created_at COLUMN_SCALAR Time
    # [[0, 1337566253.89858, 0.000355720520019531], true]
    column_create Entries_20150708 content COLUMN_SCALAR Text
    # [[0, 1337566253.89858, 0.000355720520019531], true]
    column_create Entries_20150708 n_likes COLUMN_SCALAR UInt32
    # [[0, 1337566253.89858, 0.000355720520019531], true]
    column_create Entries_20150708 tag COLUMN_SCALAR ShortText
    # [[0, 1337566253.89858, 0.000355720520019531], true]
    table_create Entries_20150709 TABLE_HASH_KEY ShortText
    # [[0, 1337566253.89858, 0.000355720520019531], true]
    column_create Entries_20150709 created_at COLUMN_SCALAR Time
    # [[0, 1337566253.89858, 0.000355720520019531], true]
    column_create Entries_20150709 content COLUMN_SCALAR Text
    # [[0, 1337566253.89858, 0.000355720520019531], true]
    column_create Entries_20150709 n_likes COLUMN_SCALAR UInt32
    # [[0, 1337566253.89858, 0.000355720520019531], true]
    column_create Entries_20150709 tag COLUMN_SCALAR ShortText
    # [[0, 1337566253.89858, 0.000355720520019531], true]
    table_create Terms TABLE_PAT_KEY ShortText \
      --default_tokenizer TokenBigram \
      --normalizer NormalizerAuto
    # [[0, 1337566253.89858, 0.000355720520019531], true]
    column_create Terms entries_key_index_20150708 \
      COLUMN_INDEX|WITH_POSITION Entries_20150708 _key
    # [[0, 1337566253.89858, 0.000355720520019531], true]
    column_create Terms entries_content_index_20150708 \
      COLUMN_INDEX|WITH_POSITION Entries_20150708 content
    # [[0, 1337566253.89858, 0.000355720520019531], true]
    column_create Terms entries_key_index_20150709 \
      COLUMN_INDEX|WITH_POSITION Entries_20150709 _key
    # [[0, 1337566253.89858, 0.000355720520019531], true]
    column_create Terms entries_content_index_20150709 \
      COLUMN_INDEX|WITH_POSITION Entries_20150709 content
    # [[0, 1337566253.89858, 0.000355720520019531], true]
    load --table Entries_20150708
    [
    {"_key":       "The first post!",
     "created_at": "2015/07/08 00:00:00",
     "content":    "Welcome! This is my first post!",
     "n_likes":    5,
     "tag":        "Hello"},
    {"_key":       "Groonga",
     "created_at": "2015/07/08 01:00:00",
     "content":    "I started to use Groonga. It's very fast!",
     "n_likes":    10,
     "tag":        "Groonga"},
    {"_key":       "Mroonga",
     "created_at": "2015/07/08 02:00:00",
     "content":    "I also started to use Mroonga. It's also very fast! Really fast!",
     "n_likes":    15,
     "tag":        "Groonga"}
    ]
    # [[0, 1337566253.89858, 0.000355720520019531], 3]
    load --table Entries_20150709
    [
    {"_key":       "Good-bye Senna",
     "created_at": "2015/07/09 00:00:00",
     "content":    "I migrated all Senna system!",
     "n_likes":    3,
     "tag":        "Senna"},
    {"_key":       "Good-bye Tritonn",
     "created_at": "2015/07/09 01:00:00",
     "content":    "I also migrated all Tritonn system!",
     "n_likes":    3,
     "tag":        "Senna"}
    ]
    # [[0, 1337566253.89858, 0.000355720520019531], 2]

There are two tables, `Entries_20150708` and `Entries_20150709`, for blog entries.

Note

You need to use `${LOGICAL_TABLE_NAME}_${YYYYMMDD}` naming rule for table names. In this example, `LOGICAL_TABLE_NAME` is `Entries` and `YYYYMMDD` is `20150708` or `20150709`.

An entry has title, created time, content, the number of likes for the entry and tag. Title is key of `Entries_YYYYMMDD`. Created time is value of `Entries_YYYYMMDD.created_at` column. Content is value of `Entries_YYYYMMDD.content` column. The number of likes is value of `Entries_YYYYMMDD.n_likes` column. Tag is value of `Entries_YYYYMMDD.tag` column.

`Entries_YYYYMMDD._key` column and `Entries_YYYYMMDD.content` column are indexed using `TokenBigram` tokenizer. So both `Entries_YYYYMMDD._key` and `Entries_YYYYMMDD.content` are fulltext search ready.

OK. The schema and data for examples are ready.

### 7.3.34.4.1. Simple usage

TODO

## 7.3.34.5. Parameters

This section describes parameters of `logical_select`.

### 7.3.34.5.1. Required parameters

There are required parameters, `logical_table` and `shard_key`.

#### 7.3.34.5.1.1. `logical_table`

Specifies logical table name. It means table name without `_YYYYMMDD` postfix. If you use actual table such as `Entries_20150708`, `Entries_20150709` and so on, logical table name is `Entries`.

You can show 10 records by specifying `logical_table` and `shard_key` parameters. They are required parameters.

Execution example:

    logical_select --logical_table Entries --shard_key created_at
    # [
    #   [
    #     0,
    #     1337566253.89858,
    #     0.000355720520019531
    #   ],
    #   [
    #     [
    #       [
    #         5
    #       ],
    #       [
    #         [
    #           "_id",
    #           "UInt32"
    #         ],
    #         [
    #           "_key",
    #           "ShortText"
    #         ],
    #         [
    #           "content",
    #           "Text"
    #         ],
    #         [
    #           "created_at",
    #           "Time"
    #         ],
    #         [
    #           "n_likes",
    #           "UInt32"
    #         ],
    #         [
    #           "tag",
    #           "ShortText"
    #         ]
    #       ],
    #       [
    #         1,
    #         "The first post!",
    #         "Welcome! This is my first post!",
    #         1436281200.0,
    #         5,
    #         "Hello"
    #       ],
    #       [
    #         2,
    #         "Groonga",
    #         "I started to use Groonga. It's very fast!",
    #         1436284800.0,
    #         10,
    #         "Groonga"
    #       ],
    #       [
    #         3,
    #         "Mroonga",
    #         "I also started to use Mroonga. It's also very fast! Really fast!",
    #         1436288400.0,
    #         15,
    #         "Groonga"
    #       ],
    #       [
    #         1,
    #         "Good-bye Senna",
    #         "I migrated all Senna system!",
    #         1436367600.0,
    #         3,
    #         "Senna"
    #       ],
    #       [
    #         2,
    #         "Good-bye Tritonn",
    #         "I also migrated all Tritonn system!",
    #         1436371200.0,
    #         3,
    #         "Senna"
    #       ]
    #     ]
    #   ]
    # ]

If nonexistent table is specified, an error is returned.

Execution example:

    logical_select --logical_table Nonexistent --shard_key created_at
    # [
    #   [
    #     -22,
    #     1337566253.89858,
    #     0.000355720520019531,
    #     "[logical_select] no shard exists: logical_table: <Nonexistent>: shard_key: <created_at>",
    #     [
    #       [
    #         "Groonga::Context.set_groonga_error",
    #         "lib/mrb/scripts/context.rb",
    #         27
    #       ]
    #     ]
    #   ]
    # ]

#### 7.3.34.5.1.2. `shard_key`

Specifies column name which is treated as shared key. Shard key is a column that stores data that is used for distributing records to suitable shards.

Shard key must be `Time` type for now.

See logical_table how to specify `shard_key`.

### 7.3.34.5.2. Optional parameters

There are optional parameters.

#### 7.3.34.5.2.1. `min`

Specifies the minimum value of `shard_key` column. If shard doesn't have any matched records, the shard isn't searched.

For example, `min` is `"2015/07/09 00:00:00"`, `Entry_20150708` isn't searched. Because `Entry_20150708` has only records for `"2015/07/08"`.

The following example only uses `Entry_20150709` table. `Entry_20150708` isn't used.

Execution example:

    logical_select \
      --logical_table Entries \
      --shard_key created_at \
      --min "2015/07/09 00:00:00"
    # [
    #   [
    #     0,
    #     1337566253.89858,
    #     0.000355720520019531
    #   ],
    #   [
    #     [
    #       [
    #         2
    #       ],
    #       [
    #         [
    #           "_id",
    #           "UInt32"
    #         ],
    #         [
    #           "_key",
    #           "ShortText"
    #         ],
    #         [
    #           "content",
    #           "Text"
    #         ],
    #         [
    #           "created_at",
    #           "Time"
    #         ],
    #         [
    #           "n_likes",
    #           "UInt32"
    #         ],
    #         [
    #           "tag",
    #           "ShortText"
    #         ]
    #       ],
    #       [
    #         1,
    #         "Good-bye Senna",
    #         "I migrated all Senna system!",
    #         1436367600.0,
    #         3,
    #         "Senna"
    #       ],
    #       [
    #         2,
    #         "Good-bye Tritonn",
    #         "I also migrated all Tritonn system!",
    #         1436371200.0,
    #         3,
    #         "Senna"
    #       ]
    #     ]
    #   ]
    # ]

#### 7.3.34.5.2.2. `min_border`

Specifies whether the minimum value is included or not. Here is available values.

Value | Description
--- | ---
`include` | Includes `min` value. This is the default.
`exclude` | Doesn't include `min` value.

Here is an example for `exclude`. The result doesn't include the `"Good-bye Senna"` record because its `created_at` value is `"2015/07/09 00:00:00"`.

Execution example:

    logical_select \
      --logical_table Entries \
      --shard_key created_at \
      --min "2015/07/09 00:00:00" \
      --min_border "exclude"
    # [
    #   [
    #     0,
    #     1337566253.89858,
    #     0.000355720520019531
    #   ],
    #   [
    #     [
    #       [
    #         1
    #       ],
    #       [
    #         [
    #           "_id",
    #           "UInt32"
    #         ],
    #         [
    #           "_key",
    #           "ShortText"
    #         ],
    #         [
    #           "content",
    #           "Text"
    #         ],
    #         [
    #           "created_at",
    #           "Time"
    #         ],
    #         [
    #           "n_likes",
    #           "UInt32"
    #         ],
    #         [
    #           "tag",
    #           "ShortText"
    #         ]
    #       ],
    #       [
    #         2,
    #         "Good-bye Tritonn",
    #         "I also migrated all Tritonn system!",
    #         1436371200.0,
    #         3,
    #         "Senna"
    #       ]
    #     ]
    #   ]
    # ]

#### 7.3.34.5.2.3. `max`

Specifies the maximum value of `shard_key` column. If shard doesn't have any matched records, the shard isn't searched.

For example, `max` is `"2015/07/08 23:59:59"`, `Entry_20150709` isn't searched. Because `Entry_20150709` has only records for `""2015/07/09"`.

The following example only uses `Entry_20150708` table. `Entry_20150709` isn't used.

Execution example:

    logical_select \
      --logical_table Entries \
      --shard_key created_at \
      --max "2015/07/08 23:59:59"
    # [
    #   [
    #     0,
    #     1337566253.89858,
    #     0.000355720520019531
    #   ],
    #   [
    #     [
    #       [
    #         3
    #       ],
    #       [
    #         [
    #           "_id",
    #           "UInt32"
    #         ],
    #         [
    #           "_key",
    #           "ShortText"
    #         ],
    #         [
    #           "content",
    #           "Text"
    #         ],
    #         [
    #           "created_at",
    #           "Time"
    #         ],
    #         [
    #           "n_likes",
    #           "UInt32"
    #         ],
    #         [
    #           "tag",
    #           "ShortText"
    #         ]
    #       ],
    #       [
    #         1,
    #         "The first post!",
    #         "Welcome! This is my first post!",
    #         1436281200.0,
    #         5,
    #         "Hello"
    #       ],
    #       [
    #         2,
    #         "Groonga",
    #         "I started to use Groonga. It's very fast!",
    #         1436284800.0,
    #         10,
    #         "Groonga"
    #       ],
    #       [
    #         3,
    #         "Mroonga",
    #         "I also started to use Mroonga. It's also very fast! Really fast!",
    #         1436288400.0,
    #         15,
    #         "Groonga"
    #       ]
    #     ]
    #   ]
    # ]

#### 7.3.34.5.2.4. `max_border`

Specifies whether the maximum value is included or not. Here is available values.

Value | Description
--- | ---
`include` | Includes `max` value. This is the default.
`exclude` | Doesn't include `max` value.

Here is an example for `exclude`. The result doesn't include the `"Good-bye Senna"` record because its `created_at` value is `"2015/07/09 00:00:00"`.

Execution example:

    logical_select \
      --logical_table Entries \
      --shard_key created_at \
      --max "2015/07/09 00:00:00" \
      --max_border "exclude"
    # [
    #   [
    #     0,
    #     1337566253.89858,
    #     0.000355720520019531
    #   ],
    #   [
    #     [
    #       [
    #         3
    #       ],
    #       [
    #         [
    #           "_id",
    #           "UInt32"
    #         ],
    #         [
    #           "_key",
    #           "ShortText"
    #         ],
    #         [
    #           "content",
    #           "Text"
    #         ],
    #         [
    #           "created_at",
    #           "Time"
    #         ],
    #         [
    #           "n_likes",
    #           "UInt32"
    #         ],
    #         [
    #           "tag",
    #           "ShortText"
    #         ]
    #       ],
    #       [
    #         1,
    #         "The first post!",
    #         "Welcome! This is my first post!",
    #         1436281200.0,
    #         5,
    #         "Hello"
    #       ],
    #       [
    #         2,
    #         "Groonga",
    #         "I started to use Groonga. It's very fast!",
    #         1436284800.0,
    #         10,
    #         "Groonga"
    #       ],
    #       [
    #         3,
    #         "Mroonga",
    #         "I also started to use Mroonga. It's also very fast! Really fast!",
    #         1436288400.0,
    #         15,
    #         "Groonga"
    #       ]
    #     ]
    #   ]
    # ]

### 7.3.34.5.3. Search related parameters

`logical_select` provides select compatible search related parameters.

`match_columns` and `query` aren't supported yet. `filter` is only supported for now.

#### 7.3.34.5.3.1. `match_columns`

Not implemented yet.

#### 7.3.34.5.3.2. `query`

Not implemented yet.

#### 7.3.34.5.3.3. `filter`

Corresponds to filter in select. See filter for details.

Here is an example:

Execution example:

    logical_select \
      --logical_table Entries \
      --shard_key created_at \
      --filter "n_likes <= 5"
    # [
    #   [
    #     0,
    #     1337566253.89858,
    #     0.000355720520019531
    #   ],
    #   [
    #     [
    #       [
    #         3
    #       ],
    #       [
    #         [
    #           "_id",
    #           "UInt32"
    #         ],
    #         [
    #           "_key",
    #           "ShortText"
    #         ],
    #         [
    #           "content",
    #           "Text"
    #         ],
    #         [
    #           "created_at",
    #           "Time"
    #         ],
    #         [
    #           "n_likes",
    #           "UInt32"
    #         ],
    #         [
    #           "tag",
    #           "ShortText"
    #         ]
    #       ],
    #       [
    #         1,
    #         "The first post!",
    #         "Welcome! This is my first post!",
    #         1436281200.0,
    #         5,
    #         "Hello"
    #       ],
    #       [
    #         1,
    #         "Good-bye Senna",
    #         "I migrated all Senna system!",
    #         1436367600.0,
    #         3,
    #         "Senna"
    #       ],
    #       [
    #         2,
    #         "Good-bye Tritonn",
    #         "I also migrated all Tritonn system!",
    #         1436371200.0,
    #         3,
    #         "Senna"
    #       ]
    #     ]
    #   ]
    # ]

### 7.3.34.5.4. Advanced search parameters

`logical_select` doesn't implement advanced search parameters yet.

#### 7.3.34.5.4.1. `match_escalation_threshold`

Not implemented yet.

#### 7.3.34.5.4.2. `query_flags`

Not implemented yet.

#### 7.3.34.5.4.3. `query_expander`

Not implemented yet.

### 7.3.34.5.5. Output related parameters

#### 7.3.34.5.5.1. `output_columns`

Corresponds to output_columns in select. See output_columns for details.

Here is an example:

Execution example:

    logical_select \
      --logical_table Entries \
      --shard_key created_at \
      --output_columns '_key, *'
    # [
    #   [
    #     0,
    #     1337566253.89858,
    #     0.000355720520019531
    #   ],
    #   [
    #     [
    #       [
    #         5
    #       ],
    #       [
    #         [
    #           "_key",
    #           "ShortText"
    #         ],
    #         [
    #           "content",
    #           "Text"
    #         ],
    #         [
    #           "created_at",
    #           "Time"
    #         ],
    #         [
    #           "n_likes",
    #           "UInt32"
    #         ],
    #         [
    #           "tag",
    #           "ShortText"
    #         ]
    #       ],
    #       [
    #         "The first post!",
    #         "Welcome! This is my first post!",
    #         1436281200.0,
    #         5,
    #         "Hello"
    #       ],
    #       [
    #         "Groonga",
    #         "I started to use Groonga. It's very fast!",
    #         1436284800.0,
    #         10,
    #         "Groonga"
    #       ],
    #       [
    #         "Mroonga",
    #         "I also started to use Mroonga. It's also very fast! Really fast!",
    #         1436288400.0,
    #         15,
    #         "Groonga"
    #       ],
    #       [
    #         "Good-bye Senna",
    #         "I migrated all Senna system!",
    #         1436367600.0,
    #         3,
    #         "Senna"
    #       ],
    #       [
    #         "Good-bye Tritonn",
    #         "I also migrated all Tritonn system!",
    #         1436371200.0,
    #         3,
    #         "Senna"
    #       ]
    #     ]
    #   ]
    # ]

#### 7.3.34.5.5.2. `sortby`

Corresponds to sortby in select. See sortby for details.

`sortby` has a limitation. It works only when the number of search target shards is one. If the number of search target shards is larger than one, `sortby` doesn't work.

Here is an example that uses only one shard:

Execution example:

    logical_select \
      --logical_table Entries \
      --shard_key created_at \
      --min "2015/07/08 00:00:00" \
      --min_border "include" \
      --max "2015/07/09 00:00:00" \
      --max_border "exclude" \
      --sortby _key
    # [
    #   [
    #     0,
    #     1337566253.89858,
    #     0.000355720520019531
    #   ],
    #   [
    #     [
    #       [
    #         3
    #       ],
    #       [
    #         [
    #           "_id",
    #           "UInt32"
    #         ],
    #         [
    #           "_key",
    #           "ShortText"
    #         ],
    #         [
    #           "content",
    #           "Text"
    #         ],
    #         [
    #           "created_at",
    #           "Time"
    #         ],
    #         [
    #           "n_likes",
    #           "UInt32"
    #         ],
    #         [
    #           "tag",
    #           "ShortText"
    #         ]
    #       ],
    #       [
    #         2,
    #         "Groonga",
    #         "I started to use Groonga. It's very fast!",
    #         1436284800.0,
    #         10,
    #         "Groonga"
    #       ],
    #       [
    #         3,
    #         "Mroonga",
    #         "I also started to use Mroonga. It's also very fast! Really fast!",
    #         1436288400.0,
    #         15,
    #         "Groonga"
    #       ],
    #       [
    #         1,
    #         "The first post!",
    #         "Welcome! This is my first post!",
    #         1436281200.0,
    #         5,
    #         "Hello"
    #       ]
    #     ]
    #   ]
    # ]

#### 7.3.34.5.5.3. `offset`

Corresponds to offset in select. See offset for details.

Here is an example:

Execution example:

    logical_select \
      --logical_table Entries \
      --shard_key created_at \
      --offset 2
    # [
    #   [
    #     0,
    #     1337566253.89858,
    #     0.000355720520019531
    #   ],
    #   [
    #     [
    #       [
    #         5
    #       ],
    #       [
    #         [
    #           "_id",
    #           "UInt32"
    #         ],
    #         [
    #           "_key",
    #           "ShortText"
    #         ],
    #         [
    #           "content",
    #           "Text"
    #         ],
    #         [
    #           "created_at",
    #           "Time"
    #         ],
    #         [
    #           "n_likes",
    #           "UInt32"
    #         ],
    #         [
    #           "tag",
    #           "ShortText"
    #         ]
    #       ],
    #       [
    #         3,
    #         "Mroonga",
    #         "I also started to use Mroonga. It's also very fast! Really fast!",
    #         1436288400.0,
    #         15,
    #         "Groonga"
    #       ],
    #       [
    #         1,
    #         "Good-bye Senna",
    #         "I migrated all Senna system!",
    #         1436367600.0,
    #         3,
    #         "Senna"
    #       ],
    #       [
    #         2,
    #         "Good-bye Tritonn",
    #         "I also migrated all Tritonn system!",
    #         1436371200.0,
    #         3,
    #         "Senna"
    #       ]
    #     ]
    #   ]
    # ]

#### 7.3.34.5.5.4. `limit`

Corresponds to limit in select. See limit for details.

Here is an example:

Execution example:

    logical_select \
      --logical_table Entries \
      --shard_key created_at \
      --limit 2
    # [
    #   [
    #     0,
    #     1337566253.89858,
    #     0.000355720520019531
    #   ],
    #   [
    #     [
    #       [
    #         5
    #       ],
    #       [
    #         [
    #           "_id",
    #           "UInt32"
    #         ],
    #         [
    #           "_key",
    #           "ShortText"
    #         ],
    #         [
    #           "content",
    #           "Text"
    #         ],
    #         [
    #           "created_at",
    #           "Time"
    #         ],
    #         [
    #           "n_likes",
    #           "UInt32"
    #         ],
    #         [
    #           "tag",
    #           "ShortText"
    #         ]
    #       ],
    #       [
    #         1,
    #         "The first post!",
    #         "Welcome! This is my first post!",
    #         1436281200.0,
    #         5,
    #         "Hello"
    #       ],
    #       [
    #         2,
    #         "Groonga",
    #         "I started to use Groonga. It's very fast!",
    #         1436284800.0,
    #         10,
    #         "Groonga"
    #       ]
    #     ]
    #   ]
    # ]

#### 7.3.34.5.5.5. `scorer`

Not implemented yet.

### 7.3.34.5.6. Drilldown related parameters

All drilldown related parameters in select are supported. See Drilldown related parameters for details.

#### 7.3.34.5.6.1. `drilldown`

Corresponds to drilldown in select. See drilldown for details.

Here is an example:

Execution example:

    logical_select \
      --logical_table Entries \
      --shard_key created_at \
      --output_columns _key,tag \
      --drilldown tag
    # [
    #   [
    #     0,
    #     1337566253.89858,
    #     0.000355720520019531
    #   ],
    #   [
    #     [
    #       [
    #         5
    #       ],
    #       [
    #         [
    #           "_key",
    #           "ShortText"
    #         ],
    #         [
    #           "tag",
    #           "ShortText"
    #         ]
    #       ],
    #       [
    #         "The first post!",
    #         "Hello"
    #       ],
    #       [
    #         "Groonga",
    #         "Groonga"
    #       ],
    #       [
    #         "Mroonga",
    #         "Groonga"
    #       ],
    #       [
    #         "Good-bye Senna",
    #         "Senna"
    #       ],
    #       [
    #         "Good-bye Tritonn",
    #         "Senna"
    #       ]
    #     ],
    #     [
    #       [
    #         3
    #       ],
    #       [
    #         [
    #           "_key",
    #           "ShortText"
    #         ],
    #         [
    #           "_nsubrecs",
    #           "Int32"
    #         ]
    #       ],
    #       [
    #         "Hello",
    #         1
    #       ],
    #       [
    #         "Groonga",
    #         2
    #       ],
    #       [
    #         "Senna",
    #         2
    #       ]
    #     ]
    #   ]
    # ]

#### 7.3.34.5.6.2. `drilldown_sortby`

Corresponds to drilldown_sortby in select. See drilldown_sortby for details.

Here is an example:

Execution example:

    logical_select \
      --logical_table Entries \
      --shard_key created_at \
      --limit 0 \
      --output_columns _id \
      --drilldown tag \
      --drilldown_sortby -_nsubrecs,_key
    # [
    #   [
    #     0,
    #     1337566253.89858,
    #     0.000355720520019531
    #   ],
    #   [
    #     [
    #       [
    #         5
    #       ],
    #       [
    #         [
    #           "_id",
    #           "UInt32"
    #         ]
    #       ]
    #     ],
    #     [
    #       [
    #         3
    #       ],
    #       [
    #         [
    #           "_key",
    #           "ShortText"
    #         ],
    #         [
    #           "_nsubrecs",
    #           "Int32"
    #         ]
    #       ],
    #       [
    #         "Groonga",
    #         2
    #       ],
    #       [
    #         "Senna",
    #         2
    #       ],
    #       [
    #         "Hello",
    #         1
    #       ]
    #     ]
    #   ]
    # ]

#### 7.3.34.5.6.3. `drilldown_output_columns`

Corresponds to drilldown_output_columns in select. See drilldown_output_columns for details.

Here is an example:

Execution example:

    logical_select \
      --logical_table Entries \
      --shard_key created_at \
      --limit 0 \
      --output_columns _id \
      --drilldown tag \
      --drilldown_output_columns _key
    # [
    #   [
    #     0,
    #     1337566253.89858,
    #     0.000355720520019531
    #   ],
    #   [
    #     [
    #       [
    #         5
    #       ],
    #       [
    #         [
    #           "_id",
    #           "UInt32"
    #         ]
    #       ]
    #     ],
    #     [
    #       [
    #         3
    #       ],
    #       [
    #         [
    #           "_key",
    #           "ShortText"
    #         ]
    #       ],
    #       [
    #         "Hello"
    #       ],
    #       [
    #         "Groonga"
    #       ],
    #       [
    #         "Senna"
    #       ]
    #     ]
    #   ]
    # ]

#### 7.3.34.5.6.4. `drilldown_offset`

Corresponds to drilldown_offset in select. See drilldown_offset for details.

Here is an example:

Execution example:

    logical_select \
      --logical_table Entries \
      --shard_key created_at \
      --limit 0 \
      --output_columns _id \
      --drilldown tag \
      --drilldown_offset 1
    # [
    #   [
    #     0,
    #     1337566253.89858,
    #     0.000355720520019531
    #   ],
    #   [
    #     [
    #       [
    #         5
    #       ],
    #       [
    #         [
    #           "_id",
    #           "UInt32"
    #         ]
    #       ]
    #     ],
    #     [
    #       [
    #         3
    #       ],
    #       [
    #         [
    #           "_key",
    #           "ShortText"
    #         ],
    #         [
    #           "_nsubrecs",
    #           "Int32"
    #         ]
    #       ],
    #       [
    #         "Groonga",
    #         2
    #       ],
    #       [
    #         "Senna",
    #         2
    #       ]
    #     ]
    #   ]
    # ]

#### 7.3.34.5.6.5. `drilldown_limit`

Corresponds to drilldown_limit in select. See drilldown_limit for details.

Here is an example:

Execution example:

    logical_select \
      --logical_table Entries \
      --shard_key created_at \
      --limit 0 \
      --output_columns _id \
      --drilldown tag \
      --drilldown_limit 2
    # [
    #   [
    #     0,
    #     1337566253.89858,
    #     0.000355720520019531
    #   ],
    #   [
    #     [
    #       [
    #         5
    #       ],
    #       [
    #         [
    #           "_id",
    #           "UInt32"
    #         ]
    #       ]
    #     ],
    #     [
    #       [
    #         3
    #       ],
    #       [
    #         [
    #           "_key",
    #           "ShortText"
    #         ],
    #         [
    #           "_nsubrecs",
    #           "Int32"
    #         ]
    #       ],
    #       [
    #         "Hello",
    #         1
    #       ],
    #       [
    #         "Groonga",
    #         2
    #       ]
    #     ]
    #   ]
    # ]

#### 7.3.34.5.6.6. `drilldown_calc_types`

Corresponds to drilldown_calc_types in select. See drilldown_calc_types for details.

Here is an example:

Execution example:

    logical_select \
      --logical_table Entries \
      --shard_key created_at \
      --limit -1 \
      --output_columns tag,n_likes \
      --drilldown tag \
      --drilldown_calc_types MAX,MIN,SUM,AVG \
      --drilldown_calc_target n_likes \
      --drilldown_output_columns _key,_nsubrecs,_max,_min,_sum,_avg
    # [
    #   [
    #     0,
    #     1337566253.89858,
    #     0.000355720520019531
    #   ],
    #   [
    #     [
    #       [
    #         5
    #       ],
    #       [
    #         [
    #           "tag",
    #           "ShortText"
    #         ],
    #         [
    #           "n_likes",
    #           "UInt32"
    #         ]
    #       ],
    #       [
    #         "Hello",
    #         5
    #       ],
    #       [
    #         "Groonga",
    #         10
    #       ],
    #       [
    #         "Groonga",
    #         15
    #       ],
    #       [
    #         "Senna",
    #         3
    #       ],
    #       [
    #         "Senna",
    #         3
    #       ]
    #     ],
    #     [
    #       [
    #         3
    #       ],
    #       [
    #         [
    #           "_key",
    #           "ShortText"
    #         ],
    #         [
    #           "_nsubrecs",
    #           "Int32"
    #         ],
    #         [
    #           "_max",
    #           "Int64"
    #         ],
    #         [
    #           "_min",
    #           "Int64"
    #         ],
    #         [
    #           "_sum",
    #           "Int64"
    #         ],
    #         [
    #           "_avg",
    #           "Float"
    #         ]
    #       ],
    #       [
    #         "Hello",
    #         1,
    #         5,
    #         5,
    #         5,
    #         5.0
    #       ],
    #       [
    #         "Groonga",
    #         2,
    #         15,
    #         10,
    #         25,
    #         12.5
    #       ],
    #       [
    #         "Senna",
    #         2,
    #         3,
    #         3,
    #         6,
    #         3.0
    #       ]
    #     ]
    #   ]
    # ]

#### 7.3.34.5.6.7. `drilldown_calc_target`

Corresponds to drilldown_calc_target in select. See drilldown_calc_target for details.

See also drilldown_calc_types for an example.

### 7.3.34.5.7. Advanced drilldown related parameters

All advanced drilldown related parameters in select are supported. See Advanced drilldown related parameters for details.

There are some limitations:

> - `_value.${KEY_NAME}` in `drilldown[${LABEL}].sortby` doesn't work with multiple shards. It works with one shard. `_key` in `drilldown[${LABEL}].sortby` work with multiple shards.

#### 7.3.34.5.7.1. `drilldown[${LABEL}].keys`

Corresponds to drilldowns[${LABEL}].keys in select. See drilldowns[${LABEL}].keys for details.

Here is an example:

Execution example:

    logical_select \
      --logical_table Entries \
      --shard_key created_at \
      --limit 0 \
      --output_columns _id \
      --drilldown[tag.n_likes].keys tag,n_likes \
      --drilldown[tag.n_likes].output_columns _value.tag,_value.n_likes,_nsubrecs
    # [
    #   [
    #     0,
    #     1337566253.89858,
    #     0.000355720520019531
    #   ],
    #   [
    #     [
    #       [
    #         5
    #       ],
    #       [
    #         [
    #           "_id",
    #           "UInt32"
    #         ]
    #       ]
    #     ],
    #     {
    #       "tag.n_likes": [
    #         [
    #           4
    #         ],
    #         [
    #           [
    #             "tag",
    #             "ShortText"
    #           ],
    #           [
    #             "n_likes",
    #             "UInt32"
    #           ],
    #           [
    #             "_nsubrecs",
    #             "Int32"
    #           ]
    #         ],
    #         [
    #           "Hello",
    #           5,
    #           1
    #         ],
    #         [
    #           "Groonga",
    #           10,
    #           1
    #         ],
    #         [
    #           "Groonga",
    #           15,
    #           1
    #         ],
    #         [
    #           "Senna",
    #           3,
    #           2
    #         ]
    #       ]
    #     }
    #   ]
    # ]

#### 7.3.34.5.7.2. `drilldown[${LABEL}].output_columns`

Corresponds to drilldowns[${LABEL}].output_columns in select. See drilldowns[${LABEL}].output_columns for details.

Here is an example:

Execution example:

    logical_select \
      --logical_table Entries \
      --shard_key created_at \
      --limit 0 \
      --output_columns _id \
      --drilldown[tag].keys tag \
      --drilldown[tag].output_columns _key,_nsubrecs
    # [
    #   [
    #     0,
    #     1337566253.89858,
    #     0.000355720520019531
    #   ],
    #   [
    #     [
    #       [
    #         5
    #       ],
    #       [
    #         [
    #           "_id",
    #           "UInt32"
    #         ]
    #       ]
    #     ],
    #     {
    #       "tag": [
    #         [
    #           3
    #         ],
    #         [
    #           [
    #             "_key",
    #             "ShortText"
    #           ],
    #           [
    #             "_nsubrecs",
    #             "Int32"
    #           ]
    #         ],
    #         [
    #           "Hello",
    #           1
    #         ],
    #         [
    #           "Groonga",
    #           2
    #         ],
    #         [
    #           "Senna",
    #           2
    #         ]
    #       ]
    #     }
    #   ]
    # ]

#### 7.3.34.5.7.3. `drilldown[${LABEL}].sortby`

Corresponds to drilldown_sortby in not labeled drilldown.

`drilldown[${LABEL}].sortby` has a limitation.

`_value.${KEY_NAME}` in `drilldown[${LABEL}].sortby` doesn't work with multiple shards. It works with one shard. `_key` in `drilldown[${LABEL}].sortby` work with multiple shards.

Here is an example that uses `_value.${KEY_NAME}` with only one shard:

Execution example:

    logical_select \
      --logical_table Entries \
      --shard_key created_at \
      --min "2015/07/08 00:00:00" \
      --min_border "include" \
      --max "2015/07/09 00:00:00" \
      --max_border "exclude" \
      --limit 0 \
      --output_columns _id \
      --drilldown[tag.n_likes].keys tag,n_likes \
      --drilldown[tag.n_likes].output_columns _nsubrecs,_value.n_likes,_value.tag \
      --drilldown[tag.n_likes].sortby -_nsubrecs,_value.n_likes,_value.tag
    # [
    #   [
    #     0,
    #     1337566253.89858,
    #     0.000355720520019531
    #   ],
    #   [
    #     [
    #       [
    #         3
    #       ],
    #       [
    #         [
    #           "_id",
    #           "UInt32"
    #         ]
    #       ]
    #     ],
    #     {
    #       "tag.n_likes": [
    #         [
    #           3
    #         ],
    #         [
    #           [
    #             "_nsubrecs",
    #             "Int32"
    #           ],
    #           [
    #             "n_likes",
    #             "UInt32"
    #           ],
    #           [
    #             "tag",
    #             "ShortText"
    #           ]
    #         ],
    #         [
    #           1,
    #           5,
    #           "Hello"
    #         ],
    #         [
    #           1,
    #           10,
    #           "Groonga"
    #         ],
    #         [
    #           1,
    #           15,
    #           "Groonga"
    #         ]
    #       ]
    #     }
    #   ]
    # ]

#### 7.3.34.5.7.4. `drilldown[${LABEL}].offset`

Corresponds to drilldown_offset in not labeled drilldown.

Here is an example:

Execution example:

    logical_select \
      --logical_table Entries \
      --shard_key created_at \
      --limit 0 \
      --output_columns _id \
      --drilldown[tag.n_likes].keys tag \
      --drilldown[tag.n_likes].offset 1
    # [
    #   [
    #     0,
    #     1337566253.89858,
    #     0.000355720520019531
    #   ],
    #   [
    #     [
    #       [
    #         5
    #       ],
    #       [
    #         [
    #           "_id",
    #           "UInt32"
    #         ]
    #       ]
    #     ],
    #     {
    #       "tag.n_likes": [
    #         [
    #           3
    #         ],
    #         [
    #           [
    #             "_key",
    #             "ShortText"
    #           ],
    #           [
    #             "_nsubrecs",
    #             "Int32"
    #           ]
    #         ],
    #         [
    #           "Groonga",
    #           2
    #         ],
    #         [
    #           "Senna",
    #           2
    #         ]
    #       ]
    #     }
    #   ]
    # ]

#### 7.3.34.5.7.5. `drilldown[${LABEL}].limit`

Corresponds to drilldown_limit in not labeled drilldown.

Here is an example:

Execution example:

    logical_select \
      --logical_table Entries \
      --shard_key created_at \
      --limit 0 \
      --output_columns _id \
      --drilldown[tag.n_likes].keys tag \
      --drilldown[tag.n_likes].limit 2
    # [
    #   [
    #     0,
    #     1337566253.89858,
    #     0.000355720520019531
    #   ],
    #   [
    #     [
    #       [
    #         5
    #       ],
    #       [
    #         [
    #           "_id",
    #           "UInt32"
    #         ]
    #       ]
    #     ],
    #     {
    #       "tag.n_likes": [
    #         [
    #           3
    #         ],
    #         [
    #           [
    #             "_key",
    #             "ShortText"
    #           ],
    #           [
    #             "_nsubrecs",
    #             "Int32"
    #           ]
    #         ],
    #         [
    #           "Hello",
    #           1
    #         ],
    #         [
    #           "Groonga",
    #           2
    #         ]
    #       ]
    #     }
    #   ]
    # ]

#### 7.3.34.5.7.6. `drilldown[${LABEL}].calc_types`

Corresponds to drilldown_calc_types in not labeled drilldown.

Here is an example:

Execution example:

    logical_select \
      --logical_table Entries \
      --shard_key created_at \
      --limit 0 \
      --output_columns _id \
      --drilldown[tag].keys tag \
      --drilldown[tag].calc_types MAX,MIN,SUM,AVG \
      --drilldown[tag].calc_target n_likes \
      --drilldown[tag].output_columns _key,_nsubrecs,_max,_min,_sum,_avg
    # [
    #   [
    #     0,
    #     1337566253.89858,
    #     0.000355720520019531
    #   ],
    #   [
    #     [
    #       [
    #         5
    #       ],
    #       [
    #         [
    #           "_id",
    #           "UInt32"
    #         ]
    #       ]
    #     ],
    #     {
    #       "tag": [
    #         [
    #           3
    #         ],
    #         [
    #           [
    #             "_key",
    #             "ShortText"
    #           ],
    #           [
    #             "_nsubrecs",
    #             "Int32"
    #           ],
    #           [
    #             "_max",
    #             "Int64"
    #           ],
    #           [
    #             "_min",
    #             "Int64"
    #           ],
    #           [
    #             "_sum",
    #             "Int64"
    #           ],
    #           [
    #             "_avg",
    #             "Float"
    #           ]
    #         ],
    #         [
    #           "Hello",
    #           1,
    #           5,
    #           5,
    #           5,
    #           5.0
    #         ],
    #         [
    #           "Groonga",
    #           2,
    #           15,
    #           10,
    #           25,
    #           12.5
    #         ],
    #         [
    #           "Senna",
    #           2,
    #           3,
    #           3,
    #           6,
    #           3.0
    #         ]
    #       ]
    #     }
    #   ]
    # ]

#### 7.3.34.5.7.7. `drilldown[${LABEL}].calc_target`

Corresponds to drilldown_calc_target in not labeled drilldown.

See also drilldown[${LABEL}].calc_types for an example.

## 7.3.34.6. Return value

The return value format of `logical_select` is compatible with select. See Return value for details.