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From "Konstantin Naryshkin" <konstant...@a-bb.net>
Subject Re: deletion questions
Date Tue, 19 Jul 2011 14:26:01 GMT
"2. Trying to reduce disk occupation I deleted CF which used 90% of available
space. After issuing a "drop column family User;" command
 no *User*.db files were deleted. "nodetool compact" haven't helped too. How
can that deletion be triggered?"

You have to wait for a garbage collect (or do a rolling restart). Those are the only times
that Cassandra deletes files. There is a better way being developed (https://issues.apache.org/jira/browse/CASSANDRA-2521).

Konstantin

----- Original Message -----
From: "Nikolai Kopylov" <kopylov@gmail.com>
To: user@cassandra.apache.org
Sent: Tuesday, July 19, 2011 1:56:15 PM
Subject: deletion questions

Hello, I'm trying to use Cassandra 0.8.1 as a media storage where
the stored items have some TTL.
So that I need to somehow delete and purge obsoleted items. I've played with
deletion columns
from db by using Thift  CassandraClient::remove call, but faced with the
problem that sstable files
become too big and I had to give Cassandra up to 100% more disk space only
for the compation process
to succeed. This is a point because I'm calculating the total disks capacity
and the data stored in column is not less than 8GB.
So for now I should build 16TB volumes, not less.
According to the above I can outline two questions.
1. Is it possible to reorganize compaction process so that the compaction
result would be not one but several files with the size upper-limited
with some parameter with default value of, say, 4GB?
2. Trying to reduce disk occupation I deleted CF which used 90% of available
space. After issuing a "drop column family User;" command
 no *User*.db files were deleted. "nodetool compact" haven't helped too. How
can that deletion be triggered?

-- 
WBR, Nikolay

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