SHOW ALTER TABLE
Description
Shows the execution of the ongoing ALTER TABLE operations, including:
- Modify columns.
- Optimize table schema (from v3.2), including modifying the bucketing method and the number of buckets.
- Create and delete the rollup index.
Syntax
-
Show the execution of operations of modifying columns or optimizing table schema.
SHOW ALTER TABLE { COLUMN | OPTIMIZE } [FROM db_name] [WHERE TableName|CreateTime|FinishTime|State] [ORDER BY] [LIMIT]
-
Show the execution of operations of adding or deleting the rollup index.
SHOW ALTER TABLE ROLLUP [FROM db_name]
Parameters
-
{COLUMN | OPTIMIZE | ROLLUP}
:- If
COLUMN
is specified, this statement shows operations of modifying columns. - If
OPTIMIZE
is specified, this statement shows operations of optimizing table structure. - If
ROLLUP
is specified, this statement shows operations of adding or deleting the rollup index.
- If
-
db_name
: optional. Ifdb_name
is not specified, the current database is used by default.
Examples
-
Show the execution of operations of modifying columns, optimizing table schema, and creating or deleting the rollup index in the current database.
SHOW ALTER TABLE COLUMN;
SHOW ALTER TABLE OPTIMIZE;
SHOW ALTER TABLE ROLLUP; -
Show the execution of operations related to modifying columns, optimizing table schema, and creating or deleting the rollup index in a specified database.
SHOW ALTER TABLE COLUMN FROM example_db;
SHOW ALTER TABLE OPTIMIZE FROM example_db;
SHOW ALTER TABLE ROLLUP FROM example_db; -
Show the execution of the most recent operation of modifying columns or optimizing table schema in a specified table.
SHOW ALTER TABLE COLUMN WHERE TableName = "table1" ORDER BY CreateTime DESC LIMIT 1;
SHOW ALTER TABLE OPTIMIZE WHERE TableName = "table1" ORDER BY CreateTime DESC LIMIT 1;