When you refer to a column as a primary key, I tend to think that this key
will be your main "relationship" point to the data in your table. Now, when
you combine the primary key concept with a BLOB (binary large object), it
seems to me that you are almost defeating the purpose of a primary key
(you'd be making the index basically useless). I have never heard of anybody
making a BLOB a primary key, so I could not comment on whether or not it is
actually do-able or possible with MySQL. If it is, it shouldn't be.
I would recommend you focus your design on creating inter-table
relationships based around smaller keys that index well, such as integers
and keep the BLOBs in a separate table, away from your frequently read data.
----- Original Message -----
From: "Lemasson Sylvain" <s.lemasson@stripped>
Sent: Monday, December 08, 2003 8:23 AM
Subject: primary key type is BLOB
I try to add a primary key on a BLOB column and I have got an error (ERROR
1170: BLOB column 'value5' used in key specification without a key length).
May be the answer is in the documentation but I did not find it. So how
could I make my BLOB column a primary key?
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