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From Mario Micklisch <mario.mickli...@hpm-kommunikation.de>
Subject problems with many columns on a row
Date Sat, 04 Jun 2011 17:27:46 GMT
Hello there!

I have ran into a strange problem several times now and I wonder if someone
here has an solution for me:


For some of my data I want to keep track all the ID's I have used. To do
that, I am putting the ID's as column into rows.

At first I wanted to put all ID's into one row (because the limit of 2
billion column seemed high enough) and then it happened:

For some reason I was no longer able to remove or update existing rows or
column. Adding new rows and removing them was possible, but write access to
the older rows did not longer work.
I have restarted the cluster, didn't help either. Only truncating the column
family helped.

Because this happened several times after creating rows with 5.000+ columns
I decided to reduce the number of columns to a maximum of 1.000 per row and
everything is now working perfectly.


I am working on version 0.8-rc1 and for testing purpose I am running only
one node with the default settings.


My questions are:

1) Because 0.8 is not marked as stable, is this a known problem?
2) Is there something in the configuration I need to change to handle a
bigger number of columns?
3) Can I check on the cassandra-cli why updates are failing? (there were no
error messages when trying deletes with the CLI manually)
4) Is there a recommended number of columns? (I guess this only depends on
my systems memory?)


Thanks to everyone who took some time to read!
 Mario

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