Gustavo,

> I need this information on client side. But, I can not open this Blob
> Field.

You want to know the blob size before fetching it, so the best way will be
to create an udf on the server to return this value to you.

> Use IBO to connectc, in Delphi 6.

Don't know if IBO can provide you this info before fetching the blob. You
should ask this in IBO-list.

> ps. I´m speak portuguese.

I notice that. :-)
You can use CFLP support list if you want to discuss this in portuguese:
http://www.comunidade-firebird.org will show you the way.

Um Abraço,

Artur