Re: [GENERAL] Image storage questions

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Re: [GENERAL] Image storage questions

Guy Rouillier
Joshua D. Drake wrote:
 
> External storing is useful but I prefer LO because all my data (binary
> and meta) is all in the same place for management.

But if that's a big L in LO, performance and maintenance will be
negatively affected, perhaps significantly.  The DBMS will have to scan
over all that large binary data to extract text or numeric data.  And
backups will copy that static binary data repeatedly.  For those
reasons, if I'm storing very large objects, like images, that I know
I'll never search or update, I prefer to manage them externally.

--
Guy Rouillier


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Re: [GENERAL] Image storage questions

Douglas McNaught
"Guy Rouillier" <[hidden email]> writes:

> Joshua D. Drake wrote:
>  
>> External storing is useful but I prefer LO because all my data (binary
>> and meta) is all in the same place for management.
>
> But if that's a big L in LO, performance and maintenance will be
> negatively affected, perhaps significantly.  The DBMS will have to scan
> over all that large binary data to extract text or numeric data.  And
> backups will copy that static binary data repeatedly.  For those
> reasons, if I'm storing very large objects, like images, that I know
> I'll never search or update, I prefer to manage them externally.

Large objects (and reasonably large text/bytea columns as well) are
stored out-of-line, so normal table scans don't have to read them
unnecessarily.

-Doug

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Re: [GENERAL] Image storage questions

Joshua D. Drake
In reply to this post by Guy Rouillier
Guy Rouillier wrote:
> Joshua D. Drake wrote:
>  
>
>>External storing is useful but I prefer LO because all my data (binary
>>and meta) is all in the same place for management.
>
>
> But if that's a big L in LO, performance and maintenance will be
> negatively affected, perhaps significantly.

How?

  The DBMS will have to scan
> over all that large binary data to extract text or numeric data.

Ahhh now I see, are you expecting to be able to query your LOs? We only
use Large Objects as a storage mechanism.

   And
> backups will copy that static binary data repeatedly.

Not unless you tell it to. If you don't pass the -b option you are not
going to end up backing up your large objects anyway.

   For those
> reasons, if I'm storing very large objects, like images, that I know
> I'll never search or update, I prefer to manage them externally.

Sincerely,

Joshua D. Drake


>


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