-Query crawls through reducer
Keith Wiley 2013-03-22, 23:02
The following query translates into a many-map-single-reduce job (which is common) and also slags through the reduce stage...it's killing the overall query:
select * from a where b >= 'c' order by b desc limit 100
Note that b is a partition. What component is making the reducer heavy? Is it the order by or the limit (I'm sure it's not the partition-specific where clause, right?)? Are there ways to improve its performance?
Keith Wiley [EMAIL PROTECTED] keithwiley.com music.keithwiley.com
"You can scratch an itch, but you can't itch a scratch. Furthermore, an itch can
itch but a scratch can't scratch. Finally, a scratch can itch, but an itch can't
scratch. All together this implies: He scratched the itch from the scratch that
itched but would never itch the scratch from the itch that scratched."
-- Keith Wiley