Subject RE: [IBO] How to use blob filter
Author Alan McDonald
> Hi,
> What i want is:
> -automatically compress data when written to a specific blob
> column via insert/update -automatically decompress data of a
> blob column when selecting via a select statement
> What i did until now is:
> -writing a dll which implements the blob filter (one for
> compressing and one for decompressing) -put the dll in udf
> folder of firebird (1.5.4) -registering the bob filter with
> declare statement
> What i could'nt get to work is:
> -invoking the filters via sql or ibobjects-api or firebird-api
> My questions:
> 1) is there a way using blob filters in sql statements?
> 2) how can i work with blob filters in ibobjects?
> 3) can i use blob filters in stored procedures? if so: what
> is the syntax?
> best regards
> falko :-)

Have a look at the contributed code section at IBObjects website, there is a
library there for the compression/decompression of blob data on the fly.
It does not use filters but appears to do the job just as nicely.
From what I have read about filters, they are dificult to setup. You need to
declare a custom sub-type for blobs in the first instance.