Subject Re: [firebird-support] Blob External Filter
Author Martijn Tonies

> > From what I've understood from a presentation by Paul at the Fulda
> > Conference, BLOB filters are hard to write if you follow the docs - and,
> > even
> > worse, impossible to use if you don't use Embedded SQL.
> Are there any examples of writing filters using Embedded SQL?

You don't need to use embedded SQL to write them, but you need
embedded SQL to use them.

> In my understanding, external filters are defined according to the
> we plan to translate, and are written in either in C or Delphi and should
> defined as a dynamic library, recognized by (defined against) the
> Thus, i can't see where Embedded SQL would fit in. Do you mean, that my
> should use Embedded SQL to support Blob data operations (insert, update,
> delete and select) ?

No, those operations can be easily done without Embedded SQL.

>Fortunately i have develop an abstraction layer (using
> APIs) to do those operations and it works fine for standard blob subtypes.
> Problem is, it doesn't work against non-standard (own-defined) subtype
> (sometimes even causing the server to crash !). My debugging have come to
> the conclusion that the filters are not working the way they are supposed
> Are there any other filter samples beside the one provided here by
> b_filter

Ehm, that's the best example around!

With regards,

Martijn Tonies
Database Workbench - the developer tool for InterBase & Firebird
Upscene Productions