"Ann W. Harrison" wrote:

> Ivan Prenosil wrote:
>>
>> Before you start developpinfg your blob filters, be aware that
>> they can't be invoked
>> - in sql command
>> - in UDF
>> - in PSQL
>>
>
> For 1 and 3, you're right. But UDFs can read blobs using the api calls,
> so they can use blob filters.

No. Blob filter is requested via BPB when _opening_ the blob.
But UDF can't open the blob - it is done by Firebird server,
and UDF just receives handle of already opened blob -
all it can do then is calling blob_get_segment using that handle.

For the same reason UDFs can't create streamed blobs as output
parameter, simply because the output blob is already created by server,
and all what UDF can do is put some data using blob_put_segment.

Ivan