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Re: Can MySql database store images?

From	"Peter H. Coffin" <hellsop@ninehells.com>
Newsgroups	comp.databases.mysql
Subject	Re: Can MySql database store images?
Date	2011-04-27 09:25 -0500
Organization	A noiseless patient Spider
Message-ID	<slrnirg9ps.2mh.hellsop@nibelheim.ninehells.com> (permalink)
References	(9 earlier) <ip6jp4$kca$1@dont-email.me> <ip7uo6$u89$1@dont-email.me> <ip8gb0$2ni$2@news.albasani.net> <slrnirg20d.2mh.hellsop@nibelheim.ninehells.com> <n3fl88-n0k.ln1@squidward.dionic.net>

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On Wed, 27 Apr 2011 13:34:31 +0100, Tim Watts wrote:
> Peter H. Coffin wrote:
>
>> On Wed, 27 Apr 2011 08:24:16 +0100, The Natural Philosopher wrote:
>>> Norman Peelman wrote:
>>>> Doug Miller wrote:
>>>>> In article <ip57sl$rc5$1@dont-email.me>, Norman Peelman
>>>>>> 460 * 5.3kb
>>>>>>
>>>>> You wrote above "460 images ... with an average size of 5393kb" .
>>>>> 5393kb is 5.4 MEGAbytes, not 5.3kb.
>>>> 
>>>>   Yes, my fingers were going faster than my brain.
>>>> 
>>>> Average of 5393 bytes (5kb)
>>>> Max of 10240 bytes (10kb)
>>>> 
>>>> ...these are small images.
>>>> 
>>>> Dump file (w/images) = 29.8MB
>>>> Dump file zipped = 1.7MB
>>>> 
>>>> 
>>> It is seldom possible to compress images more than they are already
>>> compressed.
>>>
>>> So I still think you have made a mistake.
>> 
>> Dump files can (intentionally and with malice aforethought) export
>> binary columns in hexidecimal text, which is rather compressible. It's
>> also very safe from things like people fussing with it with text
>> editors, being copied and pasted into emails for demonstrative purposes,
>> and other kinds of mistreatment.
>> 
>
> I think the point that is being overlooked, is that the text, whilst 
> compressible, is itself a re-encoding of an already highly compressed bit of 
> data.

Some parts of the file are highly-compressed data. Well,
fairly-highly-compressed, anyway. The actual compression used in, for
example JFIF/.jpeg is Huffman. More of the initial 'compression' in
those comes from not actual compression but rather lossy tricks to make
an image that looks about the same as the original to the eye, but isn't
itself 'compression' in the sense that the data inside itself isn't
necessarily further incompressible. What this means is that fairly small
images don't have a lot of "compressed data" in them in the first place,
and the overhead for graphics with small fields of image data might be
easily half overhead.

> if anything, the intermidate text encoding should make things worse overall, 
> not better.

One would think so at first glance, but text is really easy to compress.

> We are still talking about 2.2MB compressed image data mixed up with other 
> stuff in an exploded ASCII form being, somehow, recompressed down to a total 
> which is less than the sum of the original images alone.

That's the key to what I think is happening here. See, one image may be
compressible for some small gains. But many images, especially with very
similar information in the overhead portions of the formats, like
they're mostly all the same sizes, or use similar color pallets, end up
being compressable by being able to compress duplicate information
*between* the images as well as within the image itself.

> It would make me want to double check the dumps to see they really had 
> everything...

Always a worthwhile step. But if the dump restores okay, the size alone
isn't necessarily a warning that something else is wrong.

-- 
Judging by this particular thread, many people in this group spent their
school years taking illogical, pointless orders from morons and having
their will to live systematically crushed. And people say school doesn't
prepare kids for the real world. -- Rayner, in the Monastery

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Thread

Can MySql database store images? "Robert Crandal" <rcranz143101@gmail.com> - 2011-04-23 23:47 -0700
  Re: Can MySql database store images? "J.O. Aho" <user@example.net> - 2011-04-24 09:23 +0200
    Re: Can MySql database store images? "Robert Crandal" <rcranz143101@gmail.com> - 2011-04-24 01:19 -0700
      Re: Can MySql database store images? "J.O. Aho" <user@example.net> - 2011-04-24 11:13 +0200
  Re: Can MySql database store images? The Natural Philosopher <tnp@invalid.invalid> - 2011-04-24 11:17 +0100
  Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-24 13:06 +0100
  Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 08:42 -0400
    Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-24 14:45 +0100
      Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 10:27 -0400
        Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-24 19:04 +0100
          Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 14:44 -0400
            Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-24 20:51 +0100
              Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 17:03 -0400
                Re: Can MySql database store images? Hans Castorp <REWYRLXHEGHO@spammotel.com> - 2011-04-24 23:18 +0200
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 19:55 -0400
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 08:30 +0100
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 06:32 -0400
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 12:04 +0100
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 07:18 -0400
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 13:32 +0100
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 09:09 -0400
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 14:17 +0100
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 19:29 -0400
                Re: Can MySql database store images? The Natural Philosopher <tnp@invalid.invalid> - 2011-04-25 12:30 +0100
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 13:59 +0100
                Re: Can MySql database store images? The Natural Philosopher <tnp@invalid.invalid> - 2011-04-25 18:10 +0100
        Re: Can MySql database store images? Norman Peelman <npeelman@cfl.rr.com> - 2011-04-24 16:40 -0400
          Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 17:05 -0400
            Re: Can MySql database store images? Norman Peelman <npeelman@cfl.rr.com> - 2011-04-25 02:57 -0400
              Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 08:59 +0100
                Re: Can MySql database store images? Norman Peelman <npeelman@cfl.rr.com> - 2011-04-25 21:41 -0400
                Re: Can MySql database store images? Norman Peelman <npeelman@cfl.rr.com> - 2011-04-26 06:20 -0400
                Re: Can MySql database store images? dougatmilmacdotcom@example.com (Doug Miller) - 2011-04-26 14:10 +0000
                Re: Can MySql database store images? Norman Peelman <npeelman@cfl.rr.com> - 2011-04-26 22:24 -0400
                Re: Can MySql database store images? The Natural Philosopher <tnp@invalid.invalid> - 2011-04-27 08:24 +0100
                Re: Can MySql database store images? Norman Peelman <npeelman@cfl.rr.com> - 2011-04-27 06:41 -0400
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-27 12:32 +0100
                Re: Can MySql database store images? The Natural Philosopher <tnp@invalid.invalid> - 2011-04-27 15:07 +0100
                Re: Can MySql database store images? "Peter H. Coffin" <hellsop@ninehells.com> - 2011-04-27 07:11 -0500
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-27 13:34 +0100
                Re: Can MySql database store images? "Peter H. Coffin" <hellsop@ninehells.com> - 2011-04-27 09:25 -0500
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-27 16:32 +0100
      Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 10:28 -0400
        Re: Can MySql database store images? Norman Peelman <npeelman@cfl.rr.com> - 2011-04-24 16:43 -0400
          Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 08:36 +0100
            Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 06:34 -0400
              Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 11:50 +0100
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 07:20 -0400
          Re: Can MySql database store images? The Natural Philosopher <tnp@invalid.invalid> - 2011-04-25 12:42 +0100
    Re: Can MySql database store images? Luuk <Luuk@invalid.lan> - 2011-04-24 16:27 +0200
      Re: Can MySql database store images? The Natural Philosopher <tnp@invalid.invalid> - 2011-04-24 15:38 +0100
        Re: Can MySql database store images? Luuk <Luuk@invalid.lan> - 2011-04-24 16:41 +0200
        Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-24 19:07 +0100
          Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 14:46 -0400
            Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-24 21:01 +0100
              Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 17:10 -0400
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 08:23 +0100
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 06:39 -0400
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 12:00 +0100
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 07:27 -0400
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 13:42 +0100
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 09:12 -0400
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 14:23 +0100
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 19:31 -0400
                Re: Can MySql database store images? "Mr. B-o-B" <mr.chew.baka@gmail.com> - 2011-04-25 20:30 -0500
          Re: Can MySql database store images? The Natural Philosopher <tnp@invalid.invalid> - 2011-04-25 12:21 +0100
            Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 13:46 +0100
      Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 13:23 -0400
        Re: Can MySql database store images? Luuk <Luuk@invalid.lan> - 2011-04-24 20:31 +0200
          Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 14:48 -0400
            Re: Can MySql database store images? Luuk <Luuk@invalid.lan> - 2011-04-24 21:11 +0200
    Re: Can MySql database store images? Axel Schwenke <axel.schwenke@gmx.de> - 2011-04-24 21:24 +0200
      Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 17:34 -0400
        Re: Can MySql database store images? Luuk <Luuk@invalid.lan> - 2011-04-25 12:04 +0200
          Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 06:40 -0400
            Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 11:48 +0100
              Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 07:28 -0400
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 13:36 +0100
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 09:17 -0400
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 14:30 +0100
                Re: Can MySql database store images? The Natural Philosopher <tnp@invalid.invalid> - 2011-04-25 18:13 +0100
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 19:37 -0400
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 19:35 -0400
    Re: Can MySql database store images? "Robert Crandal" <rcranz143101@gmail.com> - 2011-04-24 13:13 -0700
      Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 17:35 -0400
  Re: Can MySql database store images? Axel Schwenke <axel.schwenke@gmx.de> - 2011-04-24 21:29 +0200
    Re: Can MySql database store images? "Robert Crandal" <rcranz143101@gmail.com> - 2011-04-24 14:37 -0700
      Re: Can MySql database store images? Axel Schwenke <axel.schwenke@gmx.de> - 2011-04-25 00:41 +0200
        Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 20:16 -0400
          Re: Can MySql database store images? Axel Schwenke <axel.schwenke@gmx.de> - 2011-04-25 12:12 +0200
            Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 07:31 -0400
        Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 08:43 +0100
        Re: Can MySql database store images? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2011-05-01 09:59 +0200
      Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 20:03 -0400
    Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 17:39 -0400
      Re: Can MySql database store images? Axel Schwenke <axel.schwenke@gmx.de> - 2011-04-25 00:46 +0200
        Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 20:18 -0400
          Re: Can MySql database store images? Luuk <Luuk@invalid.lan> - 2011-04-25 12:13 +0200
            Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 06:43 -0400
              Re: Can MySql database store images? Luuk <Luuk@invalid.lan> - 2011-04-25 13:40 +0200
                Re: Can MySql database store images? The Natural Philosopher <tnp@invalid.invalid> - 2011-04-25 12:43 +0100
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 09:19 -0400
                Re: Can MySql database store images? Luuk <Luuk@invalid.lan> - 2011-04-25 16:46 +0200

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