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From "Raymond Kroeker" <raym...@thinkparity.com>
Subject Re: Query on a blob table
Date Tue, 24 Jul 2007 15:47:38 GMT
Sorry about that I'm using Derby 10.2.2.0.

Raymond

On 7/23/07, Piet Blok <pbhome@wanadoo.nl> wrote:
>
>  Raymond,
>
> Some time ago I encountered the same problem and reported it here in a
> thread "Strange performance issue with BLOB's". I also found a workaround
> for this problem:
>
> If this is your original query:
> select sum(CONTENT_SIZE) from DOCUMENT_VERSION;
> add a dummy WHERE clause like this:
> select sum(CONTENT_SIZE) from DOCUMENT_VERSION where DOCUMENT_ID > 0;
>
> (assuming ofcourse that DOCUMENT_ID is a positive number)
>
>
> Kind regards,
>
> Piet Blok
>
> ----- Original Message -----
> *From:* Raymond Kroeker <raymond@thinkparity.com>
> *To:* derby-user@db.apache.org
> *Sent:* Tuesday, July 24, 2007 3:20 AM
> *Subject:* Query on a blob table
>
> Hi All,
>     I have a table encompassing blobs as such:
>
> CREATE TABLE DOCUMENT_VERSION
> (
>    DOCUMENT_ID BIGINT not null,
>    CONTENT BLOB not null,
>    CONTENT_SIZE BIGINT not null,
>    CONTENT_CHECKSUM VARCHAR(256) not null,
>    CHECKSUM_ALGORITHM VARCHAR(16) not null,
>    CONSTRAINT DOCUMENT_VERSION_PK PRIMARY KEY (DOCUMENT_ID)
> );
>
>
>   Now I've loaded 175 rows of 256B blobs and a single row containing a
> 250MB blob.  When I run the query
>
> select sum(CONTENT_SIZE) from DOCUMENT_VERSION;
>
>   it takes ~10s += 1.5s to complete.  Am I missing something?
>
>   I've tried indexing CONTENT_SIZE (after seeding the data) without any
> luck.
>
> --
>
> --------------------------------------------------------------------------------
> Raymond Kroeker
> thinkParity Solutions Inc.
>
>


-- 
--------------------------------------------------------------------------------
Raymond Kroeker
thinkParity Solutions Inc.

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