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From David Van Couvering <da...@vancouvering.com>
Subject Re: Fluctuating disk overhead
Date Mon, 23 Aug 2010 17:55:08 GMT
Sorry, about that, new mouse and I did a premature send...

As I was saying...

Here is the table definition:

CREATE TABLE BLOBTEST(ID INTEGER PRIMARY KEY, BLOBCOL BLOB)

I insert 100 rows, and then do a loop updating the 100 rows over and over
again.

When I watch the disk usage of the database directory, I see this pattern
repeated over and over again.

I tried adding a call to compress the table after every 100 updates, but
this had no impact.

Can you explain what is going on and what, if anything, I can do to keep the
size small?

Thanks,

David

$ du -s -h BLOBTEST
3.3M    BLOBTEST

$ du -s -h BLOBTEST
3.4M    BLOBTEST

$ du -s -h BLOBTEST
4.9M    BLOBTEST

$ du -s -h BLOBTEST
5.9M    BLOBTEST

$ du -s -h BLOBTEST
6.5M    BLOBTEST

$ du -s -h BLOBTEST
7.0M    BLOBTEST

$ du -s -h BLOBTEST
8.6M    BLOBTEST

$ du -s -h BLOBTEST
8.7M    BLOBTEST

$ du -s -h BLOBTEST
8.7M    BLOBTEST

$ du -s -h BLOBTEST
9.7M    BLOBTEST

$ du -s -h BLOBTEST
11M     BLOBTEST

$ du -s -h BLOBTEST
12M     BLOBTEST

$ du -s -h BLOBTEST
11M     BLOBTEST

$ du -s -h BLOBTEST
13M     BLOBTEST

$ du -s -h BLOBTEST
14M     BLOBTEST

$ du -s -h BLOBTEST
4.3M    BLOBTEST

On Mon, Aug 23, 2010 at 10:49 AM, David Van Couvering <
david@vancouvering.com> wrote:

> Hi, all.  I have a test that updates 100 rows, each of which contains an
> int primary key and a 300-byte BLOB:
>
>
>
> --
> David W. Van Couvering
>
> http://www.linkedin.com/in/davidvc
> http://davidvancouvering.blogspot.com
> http://twitter.com/dcouvering
>



-- 
David W. Van Couvering

http://www.linkedin.com/in/davidvc
http://davidvancouvering.blogspot.com
http://twitter.com/dcouvering

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