Manual:objectcache table

MediaWiki database layout

objectcache table

MediaWiki version:

≥ 1.3

The objectcache table is the default backend for the Main Stash service, and is also used by a small number of high-impact cache operations as fallback when no other cache backend is configured (e.g. Memcached ). Its content can be safely deleted and excluded from backups as it will be regenerated when needed.

See Object cache for how this cache is used and how it can be configured.

Fields

keyname

Unique identifier of the cached object. e.g. <instance>:user:id:<userid>

value

Cached object.

exptime

Date the cache entry should be expired (in seconds), and therefore removed.

modtoken

MediaWiki version:

≥ 1.37

?

flags

MediaWiki version:

≥ 1.37

?

Schema summary

MediaWiki version:

≥ 1.37

Gerrit change 666780

DESCRIBE objectcache;

+----------+------------------+------+-----+-------------------+-------+
| Field    | Type             | Null | Key | Default           | Extra |
+----------+------------------+------+-----+-------------------+-------+
| keyname  | varbinary(255)   | NO   | PRI |                   |       |
| value    | mediumblob       | YES  |     | NULL              |       |
| exptime  | binary(14)       | NO   | MUL | NULL              |       |
| modtoken | varbinary(17)    | NO   |     | 00000000000000000 |       |
| flags    | int(10) unsigned | YES  |     | NULL              |       |
+----------+------------------+------+-----+-------------------+-------+

MediaWiki version:

1.36

Gerrit change 636049

DESCRIBE objectcache;

+---------+----------------+------+-----+---------+-------+
| Field   | Type           | Null | Key | Default | Extra |
+---------+----------------+------+-----+---------+-------+
| keyname | varbinary(255) | NO   | PRI |         |       |
| value   | mediumblob     | YES  |     | NULL    |       |
| exptime | binary(14)     | NO   | MUL | NULL    |       |
+---------+----------------+------+-----+---------+-------+

MediaWiki versions:

1.10 – 1.35

DESCRIBE objectcache;

+---------+----------------+------+-----+---------+-------+
| Field   | Type           | Null | Key | Default | Extra |
+---------+----------------+------+-----+---------+-------+
| keyname | varbinary(255) | NO   | PRI |         |       |
| value   | mediumblob     | YES  |     | NULL    |       |
| exptime | datetime       | YES  | MUL | NULL    |       |
+---------+----------------+------+-----+---------+-------+

MediaWiki versions:

1.3 – 1.9

DESCRIBE objectcache;

+---------+------------------+------+-----+---------+-------+
| Field   | Type             | Null | Key | Default | Extra |
+---------+------------------+------+-----+---------+-------+
| keyname | char(255) binary | NO   | PRI | NULL    |       |
| value   | mediumblob       | YES  |     | NULL    |       |
| exptime | datetime         | YES  | MUL | NULL    |       |
+---------+------------------+------+-----+---------+-------+