Is all the lag/server lag stuff because of changes to render distance?

[Fenrys]

Sounds like you maxed out the database server's RAM and the game was running at write speed of the disk system?

Every time a player wants to repair their sundy, they'd have to wait for the disk to finish writing the new value before they can add the next repair tick . . .
The disk heads are busy writing an excessive number of saves, so read access is impaired.
At the same time you lose read speed between disk and cache, the cache is constantly getting flushed to make room for all the character saves in RAM, leading to extra time spent reading, slowing down the writes, creating a viscous spiral.
The result is it takes a long time for clients to get update information from the database.