Subject Re: Full joins...
Author Svein Erling Tysvær
That's at least not true for Fb 1.0.2, which I am still using.

I simply did:

select * from rdb$fields f
left join rdb$database d on d.rdb$relation_id = f.rdb$segment_length

and it returned all records in rdb$fields even though many had NULL in

Are you saying that this has changed in Firebird 1.5 and that the above query
would return only those records that had did not have a NULL value in
rdb$fields.rdb$segment_length ???


--- In, Jonathan Neve wrote:
> Hi!
> I've discovered to my dismay something that you all have probably known
> for a long time: a left outer join only returns a record if the field
> being joined on in the main table is non-null! (Feel free to correct me
> if I've misunderstood something)
> 1) Why????
> 2) I found that a full join works... but it's unbearably slow!
> Thanks!
> Jonathan Neve.