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From:Paul McCullagh Date:February 17 2010 7:59am
Subject:Re: how things get messed up
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<plug>
Just like to mention that http://www.blobstreaming.org was created to  
solve this problem in MySQL.

The Launchpad project is here: https://launchpad.net/pbxt
</plug>

On Feb 16, 2010, at 3:23 PM, Johan De Meersman wrote:

> On Mon, Feb 15, 2010 at 10:53 AM, Martijn Tonies  
> <m.tonies@stripped>wrote:
>
>> databases are made for storing data - it saves you on both database  
>> and PHP
>>> requests, as (from a web point of view) you can't return the image  
>>> data
>>> inside your HTML - it requires a second HTTP call. Filesystem image
>>> serving,
>>>
>>
>> Doesn't an image always required additional http calls from the  
>> <IMG> tag?
>
>
> Yes, that's what I'm saying. However, there's a significant difference
> between an HTTP call that only needs to pump a file on to the  
> network, and
> an HTTP call that needs to start a PHP process that then in turn  
> needs to
> connect to the DB, which then needs to parse and execute a query.
>
> Offloading static files (images, css, whatnot) to a separate server  
> that
> runs a lightweight, threaded httpd without PHP and whatnot compiled  
> in, also
> means that you'll need less hardware to serve the same amount of  
> requests -
> our PHP machines typically run 400 apache processes, but a static  
> server on
> the same hardware could easily serve a few thousand threads -  
> suddenly it's
> not memory/cpu but disk/network bandwidth that becomes your  
> bottleneck.
>
>
>
>> If you do go for BLOBs, though, for god's sake keep them in a  
>> separate
>>> table, lest you fragment your datafiles. Split records are a  
>>> disaster for
>>> performance.
>>>
>>
>> I agree -for MySQL-, but this is a MySQL limitation!! Not a DBMS one.
>
>
> True. I think (but am too lazy to verify) that even in MySQL this is  
> mainly
> an issue with MyISAM, not InnoDB. Given how MyISAM is the default  
> engine,
> though, I thought it worthwile to mention.
>
> Separate LOB storage still leaves the overhead of query parsing and  
> other
> generic DBMS stuff which isn't there on a filesystem, though, not to  
> mention
> that each image requests takes up a database connection for as long  
> as it
> takes to transfer the (potentially huge) data. Don't forget that in a
> well-tuned database, network transfer is often a significant part of  
> your
> total connection lifetime for select statements.
>
>
>
> -- 
> Bier met grenadyn
> Is als mosterd by den wyn
> Sy die't drinkt, is eene kwezel
> Hy die't drinkt, is ras een ezel

Thread
how things get messed upJohn G. Heim10 Feb
  • Re: how things get messed upBuford Tannen10 Feb
  • RE: how things get messed upIlya Kazakevich10 Feb
    • Re: how things get messed upCui Shijun11 Feb
      • RE: how things get messed upJerry Schwartz11 Feb
        • Re: how things get messed upJohan De Meersman12 Feb
    • Re: how things get messed upJoerg Bruehe11 Feb
    • Re: how things get messed upJochem van Dieten11 Feb
  • Re: how things get messed upMartijn Tonies11 Feb
    • Re: how things get messed upDavid Giragosian11 Feb
  • RE: how things get messed upJerry Schwartz11 Feb
  • Re: how things get messed upMartijn Tonies11 Feb
    • RE: how things get messed upJerry Schwartz11 Feb
    • Re: how things get messed upAnn W. Harrison12 Feb
  • Re: how things get messed upMartijn Tonies12 Feb
    • Re: how things get messed upJohan De Meersman12 Feb
  • Re: how things get messed upMartijn Tonies12 Feb
    • Re: how things get messed upJohan De Meersman12 Feb
      • Re: how things get messed upVikram A12 Feb
        • Re: how things get messed upJohan De Meersman12 Feb
          • Re: how things get messed upVikram A12 Feb
            • RE: how things get messed upJerry Schwartz16 Feb
              • RE: how things get messed upMartin Gainty16 Feb
                • Re: how things get messed upBarry Leslie17 Feb
              • Re: how things get messed upVikram A18 Feb
                • RE: how things get messed upJerry Schwartz18 Feb
                  • Re: how things get messed upJohan De Meersman18 Feb
  • Re: how things get messed upMartijn Tonies15 Feb
  • Re: how things get messed upMartijn Tonies15 Feb
    • Re: how things get messed upJohan De Meersman16 Feb
      • Re: how things get messed upPaul McCullagh17 Feb
  • Re: how things get messed upMartijn Tonies15 Feb
    • Re: how things get messed upAnn W. Harrison15 Feb
      • Re: how things get messed upJohan De Meersman16 Feb
      • RE: how things get messed upJerry Schwartz16 Feb
  • Re: how things get messed upMartijn Tonies18 Feb
RE: how things get messed upJerry Schwartz22 Feb
  • Re: how things get messed upVikram A24 Feb