Wikia/app — pull request #4770 by macbre (2014-09-15 11:51:27+00:00)
Title: WatchedItem: avoid select/writes for anon user in WatchedItem

@Wikia/platform-team

https://wikia-inc.atlassian.net/browse/PLATFORM-460

This will save us several millions of queries a day

Backporting https://github.com/wikimedia/mediawiki-core/commit/21884f7537d6562a54241469f378229030b5bfa5#diff-64fe2609dd41ca7d16d8dff717036ed9R140

For a page view of a anon user the following select is executed:

```sql
SELECT wl_notificationtimestamp FROM `watchlist` WHERE wl_user = '0'
AND wl_namespace = '0' AND wl_title = 'Hauptseite' LIMIT 1
```