Updating index schema

Updating index schema in RT mode

ALTER TABLE index {ADD|DROP} COLUMN column_name [{INTEGER|INT|BIGINT|FLOAT|BOOL|MULTI|MULTI64|JSON|STRING|TIMESTAMP}]

It supports adding one attribute at a time for RT indexes. The supported attribute types are:

  • int
  • bigint
  • float
  • bool
  • multi-valued
  • multi-valued 64bit
  • json
  • string

Important notes:

  • Querying an index is impossible (because of a write lock) while adding a column.
  • Newly created attribute's values are set to 0.
  • ALTER will not work for distributed indexes and indexes without any attributes.
  • DROP COLUMN will fail if an index has only one attribute.
‹›
  • Example
Example
📋

mysql> desc rt;
+------------+-----------+
| Field      | Type      |
+------------+-----------+
| id         | bigint    |
| text       | field     |
| group_id   | uint      |
| date_added | timestamp |
+------------+-----------+
4 rows in set (0.01 sec)

mysql> alter table rt add column test integer;
Query OK, 0 rows affected (0.04 sec)

mysql> desc rt;
+------------+-----------+
| Field      | Type      |
+------------+-----------+
| id         | bigint    |
| text       | field     |
| group_id   | uint      |
| date_added | timestamp |
| test       | uint      |
+------------+-----------+
5 rows in set (0.00 sec)

mysql> alter table rt drop column group_id;
Query OK, 0 rows affected (0.01 sec)

mysql> desc rt;
+------------+-----------+
| Field      | Type      |
+------------+-----------+
| id         | bigint    |
| text       | field     |
| date_added | timestamp |
| test       | uint      |
+------------+-----------+
4 rows in set (0.00 sec)

Updating index FT settings in plain mode

ALTER RTINDEX index RECONFIGURE

ALTER can also reconfigure an RT index in plain mode, so that new tokenization, morphology, and other text processing settings from the configuration file take effect on the newly INSERT-ed rows, while retaining the existing rows as they were. Internally, it forcibly saves the current RAM chunk as a new disk chunk, and adjusts the index header, so that the new rows are tokenized using the new rules.

‹›
  • Example
Example
📋
mysql> show index rt settings;
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| settings      |       |
+---------------+-------+
1 row in set (0.00 sec)

mysql> alter rtindex rt reconfigure;
Query OK, 0 rows affected (0.00 sec)

mysql> show index rt settings;
+---------------+----------------------+
| Variable_name | Value                |
+---------------+----------------------+
| settings      | morphology = stem_en |
+---------------+----------------------+
1 row in set (0.00 sec)
Collations ️ Functions