Bukkit

Version 2.1 - Performance and Help Update
 - Increased performance:
   - cached the entire database of shops
   - only access the databse on startup (to load the cache) and when a shop is editted.
   - All read functions now read from the cache and not the databse
   - Most database write methods are now async so do not hang the main thread if they are taking a while to complete
 - Plugin help features updated:
   - /shop help and /shop commands now give differing output. Helpful if you just can't remember the commands and don't want to get spammed.
   - new command: /shop alias. Shows alternate, shorter commands.
   - When the arguement length check fails, it returns the correct usage to the user so that they know how to use the command properly
 - New, shorter versions of commands, such as '/shop o' for '/shop open' and various other aliases
 - Implemented (finally!) aliases for /shop - /store and /bq
 - Fixed/added giving a wrong colour name in the config will now result in an error message and not just when the colour is not set.
 - Altered the default config configuration - now we have slightly better colours
 - Also captialised some titles in the config (doesn't affect anything, it's in a #commented out line)
 

Changes for other versions of Boutique can be found on the relevant file webpages on this website or in a file in this archive

Not really sure what'd happen if two threads are attempting to change the same line in the database. This is an outside case though. I can only think this would happen when either a spam bot would be spamming '/shop create' or an admin tries to delete someone's shop at the same time when that someone tries to change/delete theirs.
I'm pretty confident any resulting mess would affect only one user, and could easily be worked out by restarting the server or using /shop create and /shop delete to achieve the desired results