The logger is now threaded into the query controller, executor, and the
dispatcher so that we can log panics. They are logged at the info level
because the panics do not result in the system crashing and becoming
unusable.
This commit provides a new join implementation that can join
tables with different group keys. It also implements a strategy
for evicting stale data from the join operation's cache when
it can be determined that a table will no longer be joined.
Currently early table eviction from the buffers of the join occurs
when the left-most group key column of both input streams are equal
and that column is part of the join key.
Introduces the Statisticser interface which ResultIterators may
implement.
The HTTP implementation uses HTTP trailers to preserve the statistics.
This way we do not need to have all encoders and decoders support
statistics.
It was effectively a copied and pasted platform.ID, so change it to a
type alias. Once our known references to the query/id package are
updated to platform.ID, we'll delete the package.