Manual:revision_comment_temp table

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MediaWiki database layout

revision_comment_temp table

MediaWiki versions:

1.30 – 1.40

The revision_comment_temp table is a temporary table creating a relation between each row of the revision table and a row of the comment table. It has been created to avoid blocking on an alter of the revision table. On large wikis like the English Wikipedia, altering the revision table is a months-long process. This table is being created to avoid such an alter, and will be merged back into the revision table in the future.

This table was introduced in Gerrit change 357892. See also the image_comment_temp table.

Fields

revcomment_rev

Key to revision.rev_id

revcomment_comment_id

Key to comment.comment_id

Schema summary

MediaWiki versions:

1.30 – 1.40

DESCRIBE revision_comment_temp;

+-----------------------+---------------------+------+-----+---------+-------+
| Field                 | Type                | Null | Key | Default | Extra |
+-----------------------+---------------------+------+-----+---------+-------+
| revcomment_rev        | int(10) unsigned    | NO   | PRI | NULL    |       |
| revcomment_comment_id | bigint(20) unsigned | NO   | PRI | NULL    |       |
+-----------------------+---------------------+------+-----+---------+-------+

Indexes

MediaWiki versions:

1.30 – 1.40

SHOW INDEX IN revision_comment_temp;

+-----------------------+------------+----------------+--------------+-----------------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| Table                 | Non_unique | Key_name       | Seq_in_index | Column_name           | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
+-----------------------+------------+----------------+--------------+-----------------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| revision_comment_temp |          0 | PRIMARY        |            1 | revcomment_rev        | A         |           0 |     NULL | NULL   |      | BTREE      |         |               |
| revision_comment_temp |          0 | PRIMARY        |            2 | revcomment_comment_id | A         |           0 |     NULL | NULL   |      | BTREE      |         |               |
| revision_comment_temp |          0 | revcomment_rev |            1 | revcomment_rev        | A         |           0 |     NULL | NULL   |      | BTREE      |         |               |
+-----------------------+------------+----------------+--------------+-----------------------+-----------+-------------+----------+--------+------+------------+---------+---------------+