Template:Slow


 * Warning: This keyword can produce very slow and inefficient queries on your MediaWiki system, potentially impacting performance for all users. (See bug report.)

Background
This template was written by User:Maiden_taiwan after the DPL  keyword hurt performance on his MediaWiki system significantly. On a MediaWiki site with 100,000 articles and 3,000 users, this DPL took 2.5 minutes to run:

namespace= createdby=someuser

People were making these DPL calls all the time to find out what articles they had created. When two of these ran at once, it significantly hurt wiki performance.