PURGE removes selected data associated with a table. The purge target specifies what is removed.

PURGE <target> FROM TABLE <table_name>;

The only target currently supported is BULK_IMPORT.

PURGE BULK_IMPORT FROM TABLE products [OPTION clear_sessions=0|1];

PURGE BULK_IMPORT removes the entire staging root used by bulk import, including directories and files left by an interrupted load. Run it only after confirming that no direct-to-disk load is active for the table.

If the table has an open or failed Shared HTTP bulk import pool, the statement is refused. With OPTION clear_sessions=1 it cancels that pool first: unpublished data is discarded, requests still writing to the pool get an error, its indexers are stopped, the table is released for ordinary writes, and then the staging root is removed. Chunks published earlier stay in the table. While the pool is attaching its chunks after a commit, the statement is refused; repeat it after the commit finishes. On Windows, while a request is still writing to the pool, the statement can fail to remove the staging root right after it cancels the pool, because the stopped indexers keep their files open for a moment; repeat it.

An open pool keeps the table reserved, so ordinary writes to it and other bulk imports of it fail, even when all its clients are gone; SHOW LOCKS shows such a table with the lock type write_allow_readers. If the clients stopped or crashed before their commit, this releases the table and discards what they staged:

PURGE BULK_IMPORT FROM TABLE products OPTION clear_sessions=1;

To publish the staged documents instead, commit the pool with a request without documents, as described in Shared HTTP bulk import.

OPTION clear_sessions=1 does not cancel private bulk import sessions: a private session releases the table with SET bulk_import=0 or when its connection closes.

The statement requires an existing local real-time table that is not in a replication cluster. It removes only direct-to-disk staging state and does not change the table schema or indexed documents. If the staging root is absent, the statement succeeds without making any changes. In configless mode, DROP TABLE also removes the table's direct-to-disk staging root and cancels its Shared pool.

SHOW WARNINGS statement can be used to retrieve the warning produced by the latest query. The error message will be returned along with the query itself:

mysql> SELECT * FROM test1 WHERE MATCH('@@title hello') \G
ERROR 1064 (42000): index test1: syntax error, unexpected TOK_FIELDLIMIT
near '@title hello'
mysql> SELECT * FROM test1 WHERE MATCH('@title -hello') \G
ERROR 1064 (42000): index test1: query is non-computable (single NOT operator)
mysql> SELECT * FROM test1 WHERE MATCH('"test doc"/3') \G
*************************** 1\. row ***************************
        id: 4
    weight: 2500
  group_id: 2
date_added: 1231721236
1 row in set, 1 warning (0.00 sec)
mysql> SHOW WARNINGS \G
*************************** 1\. row ***************************
  Level: warning
   Code: 1000
Message: quorum threshold too high (words=2, thresh=3); replacing quorum operator
         with AND operator
1 row in set (0.00 sec)