Information Schema
The StarRocks information_schema
is a database within each StarRocks instance. information_schema
contains several read-only, system-defined tables which store extensive metadata information of all objects that the StarRocks instance maintains.
View metadata via Information Schema
You can view the metadata information within a StarRocks instance by querying the content of tables in information_schema
.
The following example views metadata information about a table named sr_member
in StarRocks by querying the table tables
.
mysql> SELECT * FROM information_schema.tables WHERE TABLE_NAME like 'sr_member'\G
*************************** 1. row ***************************
TABLE_CATALOG: def
TABLE_SCHEMA: sr_hub
TABLE_NAME: sr_member
TABLE_TYPE: BASE TABLE
ENGINE: StarRocks
VERSION: NULL
ROW_FORMAT: NULL
TABLE_ROWS: 6
AVG_ROW_LENGTH: 542
DATA_LENGTH: 3255
MAX_DATA_LENGTH: NULL
INDEX_LENGTH: NULL
DATA_FREE: NULL
AUTO_INCREMENT: NULL
CREATE_TIME: 2022-11-17 14:32:30
UPDATE_TIME: 2022-11-17 14:32:55
CHECK_TIME: NULL
TABLE_COLLATION: utf8_general_ci
CHECKSUM: NULL
CREATE_OPTIONS: NULL
TABLE_COMMENT: OLAP
1 row in set (1.04 sec)
Information Schema tables
StarRocks have optimized the metadata information provided by the following tables in information_schema
:
Information Schema table name | Description |
---|---|
tables | Provides general metadata information of tables. |
tables_config | Provides additional table metadata information that is unique to StarRocks. |
tables
The following fields are provided in tables
:
Field | Description |
---|---|
TABLE_CATALOG | Name of the catalog that stores the table. |
TABLE_SCHEMA | Name of the database that stores the table. |
TABLE_NAME | Name of the table. |
TABLE_TYPE | Type of the table. Valid values: "BASE TABLE" or "VIEW". |
ENGINE | Engine type of the table. Valid values: "StarRocks", "MySQL", "MEMORY" or an empty string. |
VERSION | Applies to a feature not available in StarRocks. |
ROW_FORMAT | Applies to a feature not available in StarRocks. |
TABLE_ROWS | Row count of the table. |
AVG_ROW_LENGTH | Average row length (size) of the table. It is equivalent to DATA_LENGTH / TABLE_ROWS . Unit: Byte. |
DATA_LENGTH | Data length (size) of the table. Unit: Byte. |
MAX_DATA_LENGTH | Applies to a feature not available in StarRocks. |
INDEX_LENGTH | Applies to a feature not available in StarRocks. |
DATA_FREE | Applies to a feature not available in StarRocks. |
AUTO_INCREMENT | Applies to a feature not available in StarRocks. |
CREATE_TIME | The time when the table is created. |
UPDATE_TIME | The last time when the table is updated. |
CHECK_TIME | The last time when a consistency check is performed on the table. |
TABLE_COLLATION | The default collation of the table. |
CHECKSUM | Applies to a feature not available in StarRocks. |
CREATE_OPTIONS | Applies to a feature not available in StarRocks. |
TABLE_COMMENT | Comment on the table. |
tables_config
The following fields are provided in tables_config
:
Field | Description |
---|---|
TABLE_SCHEMA | Name of the database that stores the table. |
TABLE_NAME | Name of the table. |
TABLE_ENGINE | Engine type of the table. |
TABLE_MODEL | Table type. Valid values: "DUP_KEYS", "AGG_KEYS", "UNQ_KEYS" or "PRI_KEYS". |
PRIMARY_KEY | The primary key of a Primary Key table or a Unique Key table. An empty string is returned if the table is not a Primary Key table or a Unique Key table. |
PARTITION_KEY | The partitioning columns of the table. |
DISTRIBUTE_KEY | The bucketing columns of the table. |
DISTRIBUTE_TYPE | The data distribution method of the table. |
DISTRIBUTE_BUCKET | Number of buckets in the table. |
SORT_KEY | Sort keys of the table. |
PROPERTIES | Properties of the table. |
TABLE_ID | ID of the table. |
load_tracking_logs
This feature is supported since StarRocks v3.0.
The following fields are provided in load_tracking_logs
:
Field | Description |
---|---|
JOB_ID | The ID of the load job. |
LABEL | The label of the load job. |
DATABASE_NAME | The database that the load job belongs to. |
TRACKING_LOG | Error logs (if any) of the load job. |
Type | The type of the load job. Valid values: BROKER, INSERT, ROUTINE_LOAD and STREAM_LOAD. |
materialized_views
The following fields are provided in materialized_views
:
Field | Description |
---|---|
MATERIALIZED_VIEW_ID | ID of the materialized view |
TABLE_SCHEMA | Database in which the materialized view resides |
TABLE_NAME | Name of the materialized view |
TABLE_ROWS | Number of data rows in the materialized view, based on approximate background statistics |
MATERIALIZED_VIEW_DEFINITION | SQL definition of the materialized view |