Manual:image_comment_temp table
↑ Manual:Contents | MediaWiki database layout | image_comment_temp table |
MediaWiki versions: | 1.30 – 1.31 |
The image_comment_temp table is a temporary table creating a relation between each row of the image
table and a row of the comment
table.
It has been created to avoid blocking on an alter of the image
table.
On large wikis like Wikimedia Commons, altering the image
table is a months-long process.
This table was created to avoid such an alter, and was merged back into the image table once the image.img_description_id field was created.
This table was introduced in Gerrit change 357892. See also the revision_comment_temp table.
In MediaWiki 1.32, the image_comment_temp
table is merged into the image
table with task T188132.
After that, the image_comment_temp
table is removed.
Fields
[edit]imgcomment_name
[edit]Key to image.img_name
imgcomment_description_id
[edit]Key to comment.comment_id
Schema summary
[edit]MediaWiki versions: | 1.30 – 1.31 |
DESCRIBE image_comment_temp;
+---------------------------+---------------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +---------------------------+---------------------+------+-----+---------+-------+ | imgcomment_name | varbinary(255) | NO | PRI | NULL | | | imgcomment_description_id | bigint(20) unsigned | NO | PRI | NULL | | +---------------------------+---------------------+------+-----+---------+-------+
Indexes
[edit]MediaWiki versions: | 1.30 – 1.31 |
SHOW INDEX IN image_comment_temp;
+--------------------+------------+-----------------+--------------+---------------------------+-----------+-------------+----------+--------+------+------------+---------+---------------+ | Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment | +--------------------+------------+-----------------+--------------+---------------------------+-----------+-------------+----------+--------+------+------------+---------+---------------+ | image_comment_temp | 0 | PRIMARY | 1 | imgcomment_name | A | 0 | NULL | NULL | | BTREE | | | | image_comment_temp | 0 | PRIMARY | 2 | imgcomment_description_id | A | 0 | NULL | NULL | | BTREE | | | | image_comment_temp | 0 | imgcomment_name | 1 | imgcomment_name | A | 0 | NULL | NULL | | BTREE | | | +--------------------+------------+-----------------+--------------+---------------------------+-----------+-------------+----------+--------+------+------------+---------+---------------+