Skip to content

Latest commit

 

History

History
88 lines (66 loc) · 8.79 KB

describe.rst

File metadata and controls

88 lines (66 loc) · 8.79 KB
Raw

describe

Table of contents

Description

Using describe command to query metadata of the index. describe command could be only used as the first command in the PPL query.

Syntax

describe <dataSource>.<schema>.<tablename>

  • dataSource: optional. If dataSource is not provided, it resolves to opensearch dataSource.
  • schema: optional. If schema is not provided, it resolves to default schema.
  • tablename: mandatory. describe command must specify which tablename to query from.

Example 1: Fetch all the metadata

The example describes accounts index.

PPL query:

os> describe accounts;
fetched rows / total rows = 11/11
+----------------+---------------+--------------+----------------+-------------+-------------+---------------+-----------------+------------------+------------------+------------+-----------+--------------+-----------------+--------------------+---------------------+--------------------+---------------+-----------------+----------------+---------------+--------------------+--------------------+----------------------+
| TABLE_CAT      | TABLE_SCHEM   | TABLE_NAME   | COLUMN_NAME    | DATA_TYPE   | TYPE_NAME   | COLUMN_SIZE   | BUFFER_LENGTH   | DECIMAL_DIGITS   | NUM_PREC_RADIX   | NULLABLE   | REMARKS   | COLUMN_DEF   | SQL_DATA_TYPE   | SQL_DATETIME_SUB   | CHAR_OCTET_LENGTH   | ORDINAL_POSITION   | IS_NULLABLE   | SCOPE_CATALOG   | SCOPE_SCHEMA   | SCOPE_TABLE   | SOURCE_DATA_TYPE   | IS_AUTOINCREMENT   | IS_GENERATEDCOLUMN   |
|----------------+---------------+--------------+----------------+-------------+-------------+---------------+-----------------+------------------+------------------+------------+-----------+--------------+-----------------+--------------------+---------------------+--------------------+---------------+-----------------+----------------+---------------+--------------------+--------------------+----------------------|
| docTestCluster | null          | accounts     | account_number | null        | long        | null          | null            | null             | 10               | 2          | null      | null         | null            | null               | null                | 0                  |               | null            | null           | null          | null               | NO                 |                      |
| docTestCluster | null          | accounts     | firstname      | null        | text        | null          | null            | null             | 10               | 2          | null      | null         | null            | null               | null                | 1                  |               | null            | null           | null          | null               | NO                 |                      |
| docTestCluster | null          | accounts     | address        | null        | text        | null          | null            | null             | 10               | 2          | null      | null         | null            | null               | null                | 2                  |               | null            | null           | null          | null               | NO                 |                      |
| docTestCluster | null          | accounts     | balance        | null        | long        | null          | null            | null             | 10               | 2          | null      | null         | null            | null               | null                | 3                  |               | null            | null           | null          | null               | NO                 |                      |
| docTestCluster | null          | accounts     | gender         | null        | text        | null          | null            | null             | 10               | 2          | null      | null         | null            | null               | null                | 4                  |               | null            | null           | null          | null               | NO                 |                      |
| docTestCluster | null          | accounts     | city           | null        | text        | null          | null            | null             | 10               | 2          | null      | null         | null            | null               | null                | 5                  |               | null            | null           | null          | null               | NO                 |                      |
| docTestCluster | null          | accounts     | employer       | null        | text        | null          | null            | null             | 10               | 2          | null      | null         | null            | null               | null                | 6                  |               | null            | null           | null          | null               | NO                 |                      |
| docTestCluster | null          | accounts     | state          | null        | text        | null          | null            | null             | 10               | 2          | null      | null         | null            | null               | null                | 7                  |               | null            | null           | null          | null               | NO                 |                      |
| docTestCluster | null          | accounts     | age            | null        | long        | null          | null            | null             | 10               | 2          | null      | null         | null            | null               | null                | 8                  |               | null            | null           | null          | null               | NO                 |                      |
| docTestCluster | null          | accounts     | email          | null        | text        | null          | null            | null             | 10               | 2          | null      | null         | null            | null               | null                | 9                  |               | null            | null           | null          | null               | NO                 |                      |
| docTestCluster | null          | accounts     | lastname       | null        | text        | null          | null            | null             | 10               | 2          | null      | null         | null            | null               | null                | 10                 |               | null            | null           | null          | null               | NO                 |                      |
+----------------+---------------+--------------+----------------+-------------+-------------+---------------+-----------------+------------------+------------------+------------+-----------+--------------+-----------------+--------------------+---------------------+--------------------+---------------+-----------------+----------------+---------------+--------------------+--------------------+----------------------+

Example 2: Fetch metadata with condition and filter

The example retrieves columns with type long in accounts index.

PPL query:

os> describe accounts | where TYPE_NAME="long" | fields COLUMN_NAME;
fetched rows / total rows = 3/3
+----------------+
| COLUMN_NAME    |
|----------------|
| account_number |
| balance        |
| age            |
+----------------+

Example 3: Fetch metadata for table in prometheus dataSource

The example retrieves table info for prometheus_http_requests_total metric in prometheus dataSource.

PPL query:

os> describe my_prometheus.prometheus_http_requests_total;
fetched rows / total rows = 6/6
+-----------------+----------------+--------------------------------+---------------+-------------+
| TABLE_CATALOG   | TABLE_SCHEMA   | TABLE_NAME                     | COLUMN_NAME   | DATA_TYPE   |
|-----------------+----------------+--------------------------------+---------------+-------------|
| my_prometheus   | default        | prometheus_http_requests_total | handler       | keyword     |
| my_prometheus   | default        | prometheus_http_requests_total | code          | keyword     |
| my_prometheus   | default        | prometheus_http_requests_total | instance      | keyword     |
| my_prometheus   | default        | prometheus_http_requests_total | @timestamp    | timestamp   |
| my_prometheus   | default        | prometheus_http_requests_total | @value        | double      |
| my_prometheus   | default        | prometheus_http_requests_total | job           | keyword     |
+-----------------+----------------+--------------------------------+---------------+-------------+