This change significantly simplifies query executor code. Before this
change there were two types of executors -- RawExecutor and
AggregateExecutor. These two types only differed in one function
Execute(). Otherwise all other methods on the Executors were common and
duplicated between executors
This change merges the two executors into a single type called, wait for
it, Executor and simply switches execute functions depending on the
statement type.
The multiple checks for Mapper and Executor type -- the lack of DRYness
in this code -- meant the same checks would need to be copied. Therefore
this change, as well as fixing the bug, improves the situation a little
bit by *asking* the Mappers what type of Executor is required. This code
is still not ideal.
Fixes#3355.
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.
Statements were only being normalized if a default database was included
in the query (usually via the query param 'db'). However if no default
database was included, and none was an explicit part of the measurement
name, no database-existence check was run. This result in a later panic
with wildcard expansion.
* Add deleteMeasurement to store and shard
* Add DropMeasurement to DatabaseIndex
* Update ErrMeasurementNotFound and ErrDatabaseNotFound to not include the first line of the stack trace.
* Pulled over updates to ast and parser from master
* Updated store and shard to be able to drop series
* Pulled updates to database.go from master into tsdb/meta.go
David Norton
Philip O'Toole
Ben Johnson
Philip O'Toole
gunnaraasen
Alexander Morozov
Joseph Crail
Pradeep Chhetri
Paul Dix
Cory LaNou