* Update the store to remove the WAL directories associated with a shard or database when they are deleted.
* Fix the Store so that it creates separate WAL directories for databases and retention policies.
This commit fixes the b1 cursor so that reads from either the cache
or bolt buffer will check against the previously read key to ensure
that two of the same keys are not returned.
Fixes#3571.
With this change, the query engine code gathers information about
shards and tagsets by working with individual shards, collating the
information, and returning that to the client. It does not assume that any
particular shard is local, and accesses all shards through abstracted
Mappers, of which there are two types -- a Mapper type for Raw queries
and a second type for Aggregate queries. There are corresponding
Executors for each type of Mapper, but both types of Executors share the
same interface.
Ben Johnson
Philip O'Toole
Cory LaNou
David Norton
Paul Dix
Philip O'Toole