incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Donal Zang <zan...@ihep.ac.cn>
Subject Re: [SPAM] Re: slow insertion rate with secondary index
Date Mon, 06 Jun 2011 08:05:14 GMT
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
zangds@ihep.ac.cn
86 010 8823 6018



Mime
View raw message