Another use of BLOB fields would be to store things like fingerprints or
retina scans, which could be very useful if you have a security-oriented
table that needs to store biometric data.
I should note that I have never actually stored biometric data or worked
with it but I saw an overhead once that said it could be done. I have no
idea what file format biometrics would use or how you would get them from
the fingerprint/retina scanner into the database though.
----- Original Message -----
From: "Daniel Lahey" <drlahey@stripped>
To: "mysql" <mysql@stripped>
Sent: Friday, August 06, 2004 11:03 PM
Subject: Re: What would you store in a BLOB field?
> Another use for binary columns is for case-sensitive text such as
> passwords. If you store text in a CHAR, VARCHAR, or TEXT column,
> comparisons will not be case-sensitive unless you use the BINARY
> keyword. An example (from section 6.3.22 of the Language Reference:
> mysql> SELECT "a" = "A";
> -> 1
> mysql> SELECT BINARY "a" = "A";
> -> 0
> On Aug 6, 2004, at 7:10 PM, Dan Nelson wrote:
> > In the last episode (Aug 06), Levi Campbell said:
> >> I know the blob field is binary but what would you store there? and
> >> if you could give me an example of real-life uses please.
> > Say you want to have multiple remote webservers all serving the same
> > data. Create a table with "filename", "mtime", and "content" fields
> > and replicate it to a mysql database on each server. The "content"
> > field would be a blob. You could also add custom HTML fields, like
> > Content-Type: and Expires:.
> > You could have an employee table, with their photo in a blob field.
> > You could implement your own full-text index by creating a table next
> > to a table of documents, with a "word" field, and a blob field
> > containing a compressed bitmap of documents containing that word.
> > Searches would be done by pulling the bitmaps for each search word and
> > AND/OR'ing them (I have done this; it works well).
> > --
> > Dan Nelson
> > dnelson@stripped
> > --
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