Key() returned the key and the entries. We did not always need the
entries so they would be allocated and ignored. Added a KeyAt func
that just returns the key to avoid the unnecesary entries allocation.
We were buffering up the data to write into byte slices to reduce
IO calls but at larger sizes, this causes memory to spike. The TSMWriter
was switched to use a bufio.Writer internally so this byte slice buffering
is unnecessary and costly now.
This has a few changes in it (unfortuantely). The main change is to run compactions
concurrently. While implementing this, a few query and performance bugs showed up that
are also fixed by this commit.
Jason Wilder
Joe LeGasse