[Chandler-dev] chandlerdb updated (0.7-8)

[Andi Vajda]

After your next 'svn update' you need to get the latest chandlerdb version
by running in 'chandler':
      make chandlerdb  - OR -
      make

This update introduces a fix to an egregious bug that affected concurrent 
db throughput in a nasty way. That bug caused a higher than necessary read 
access isolation level to be used, causing uncessary locking, dead locking and 
hence retries, and cache thrashing.

MVCC is still turned on but only used with the 'version' database, the only 
database where existing records are updated and where it helps in not blocking 
the UI. All other read access to the repository is now done at isolation level 
1, the one requiring the least locking.

Andi..