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Posted to user@cassandra.apache.org by AJ <aj...@dude.podzone.net> on 2011/06/10 20:18:37 UTC
Where is the Overview Documentation on Counters?
I can't find any that gives an overview of their purpose/benefits/etc,
only how to code them. I can only guess that they are more efficient
for some reason but don't know exactly why or exactly what conditions I
would choose to use them over a regular column.
Thanks!
Re: Where is the Overview Documentation on Counters?
Posted by Philippe <wa...@gmail.com>.
Ian,
Have you been able to measure the performance penalty of running at CL=ALL ?
Right now I'm spreading updates over such counter columns across workers so
they don't overlap keys and that way I don't go to CL=ALL but maybe that's
not worth it? Any input?
Thanks
Philippe
2011/6/10 Ian Holsman <ha...@holsman.net>
> Hi AJ.
>
> Counters are really cool for certain things..
>
> The main benefit (from a high level perspective) is that you don't have to
> read the record in to find the old value. (and stick a lock on the record to
> prevent it from changing underneath you).
>
> what I use them for is to increment page-views. I just read a log-line in,
> and can update the rows without having to read it beforehand.. which is nice
> performance wise.
>
> On Jun 10, 2011, at 2:18 PM, AJ wrote:
>
> > I can't find any that gives an overview of their purpose/benefits/etc,
> only how to code them. I can only guess that they are more efficient for
> some reason but don't know exactly why or exactly what conditions I would
> choose to use them over a regular column.
> >
> > Thanks!
>
>
Re: Where is the Overview Documentation on Counters?
Posted by Ian Holsman <ha...@holsman.net>.
Hi AJ.
Counters are really cool for certain things..
The main benefit (from a high level perspective) is that you don't have to read the record in to find the old value. (and stick a lock on the record to prevent it from changing underneath you).
what I use them for is to increment page-views. I just read a log-line in, and can update the rows without having to read it beforehand.. which is nice performance wise.
On Jun 10, 2011, at 2:18 PM, AJ wrote:
> I can't find any that gives an overview of their purpose/benefits/etc, only how to code them. I can only guess that they are more efficient for some reason but don't know exactly why or exactly what conditions I would choose to use them over a regular column.
>
> Thanks!