varchar character limit

[jkj2001]

It's my understanding that if you create, say, a varchar(255) field in a table, you can still add 256+ characters to it; the field will expand depending on need.

However, when does this "dynamic expansion start to break down? A thousand characters? A million?

We're debating whether to make a field of ours a blob or varchar, and this is one of the factors we'll take into account. Thanks for the advice.

[mark]

It doesn't break down. A varchar may be as big as a blob, 1 gigabyte max. A varchar field does not use any more space than needed. About the only time the length spec of a varchar field even matters is if that field is used as an aux field in a combined metamorph index.