wb_changes_subscription

Part of the Change propagation system on a Repo. See also Usage tracking.

Fields:

• cs_row_id - Auto-increment row id for internal use; primary key.
• cs_entity_id - The ID of the entity being subscribed to by the client page.
• cs_subscriber_id - The global ID (as used by the sites table) of the subscriber (by WMF conventions, the same as the database name).

+------------------+----------------+------+-----+---------+----------------+
| Field            | Type           | Null | Key | Default | Extra          |
+------------------+----------------+------+-----+---------+----------------+
| cs_row_id        | bigint(20)     | NO   | PRI | NULL    | auto_increment |
| cs_entity_id     | varbinary(255) | NO   | MUL | NULL    |                |
| cs_subscriber_id | varbinary(255) | NO   | MUL | NULL    |                |
+------------------+----------------+------+-----+---------+----------------+

NOTE: When tracking usage of entities from multiple repos, we either need distinct ID prefixes, or one table per repo, or both. An additional eu_entity_repo column would introduce a huge amount of redundant data, and would not play well with indexes.

Extra Indexes:

• cs_entity_id, cs_subscriber_id - look up a subscription, or all subscribers of an entity
• cs_subscriber_id - look up all subscriptions of a subscriber