Is there really a 10x difference between indexed CFs and non-indexed CFs? On Mon, Jun 6, 2011 at 11:05 AM, Donal Zang <zan...@ihep.ac.cn> wrote:
> On 06/06/2011 05:38, Jonathan Ellis wrote: > >> Index updates require read-before-write (to find out what the prior >> version was, if any, and update the index accordingly). This is >> random i/o. >> >> Index creation on the other hand is a lot of sequential i/o, hence >> more efficient. >> >> So, the classic bulk load advice to ingest data prior to creating >> indexes applies. >> > Thanks for the explanation! > > -- > Donal Zang > Computing Center, IHEP > 19B YuquanLu, Shijingshan District,Beijing, 100049 > zan...@ihep.ac.cn > 86 010 8823 6018 > > >
