Last modified: 2013-10-10 13:29:15 UTC
Some SQL queries on the replica tables take much longer than on the Toolserver. For example, this query for the first edit of a user takes 0.01 sec on the Toolserver and 49.08 sec on Tool Labs (for dewiki_p): select rev_timestamp from revision where rev_user=336793 order by rev_timestamp asc limit 1; This is critical for tools as `stimmberechtigung` that checks the right to vote of a user in the German Wikipedia (Toolserver: toolserver.org/~stimmberechtigung/, Labs: tools.wmflabs.org/stimmberechtigung/). While it runs very fast on the Toolserver, it takes several minutes to load it on Labs.
For queries that select on rev_user, there is the table "revision_userindex": | MariaDB [dewiki_p]> select rev_timestamp from revision_userindex where rev_user=336793 order by rev_timestamp asc limit 1; | +----------------+ | | rev_timestamp | | +----------------+ | | 20070115154431 | | +----------------+ | 1 row in set (0.05 sec) | MariaDB [dewiki_p]> Unfortunately, it isn't documented at [[wikitech:Nova Resource:Tools/Help]] (so far :-)). I'll leave that to Coren as my knowledge of what and when is purely based on word of mouth.
Hi Tim, thanks! This helps a lot. My tool is now working fine. :) Of course, it would be great to have this documented for further use.
I've added a first pass on documenting this to the Tool Labs help, see https://wikitech.wikimedia.org/wiki/Nova_Resource:Tools/Help#Tables_for_revision_or_logging_queries_involving_user_names_and_IDs
The canonical source of information for what "special" views exists is the source of the maintenance script: https://git.wikimedia.org/blob/operations%2Fsoftware/HEAD/maintain-replicas%2Fmaintain-replicas.pl Where the definition of the views themselves can be found.
Has been documented since.
