Dear Isaac,

Your use case is well taken here. We have users are trying to do similar 
things. It's a matter of inner join v.s. left join. The current behaviour in 
BioMart is that the joins are inner join, ie, only intersection will be 
returned in the result. It is currently not possible to alter this behaviour. 
We are thinking to introduce a flag in the configuration to let deployer 
control the join behaviour.

You mentioned that even you did not include any ensembl attribute in the query, 
you still get only the intersection. This is strange, is there any ensembl 
filter used in the query? As you would imagine, if a query only involves 
attribute/filter from one dataset, there shouldn't be any join at all. To 
further diagnose the problem, you may want to look into the log and find out 
how query is executed.

Let me know how you find.

Cheers,
Junjun


From: Isaac cano <[email protected]<mailto:[email protected]>>
Date: Wed, 20 Jul 2011 11:33:04 -0400
To: BioMart Users <[email protected]<mailto:[email protected]>>
Subject: [BioMart Users] Importing from sources

Dear BioMart users,

I'm dealing with BioMart to annotate a local database by importing several 
attributes from the Ensembl mart (homo sapiens). Now I've created a 
configuration for the Ensembl source and imported the local attributes to it.

The general point is that we would like to retrieve all the data stored in the 
local database plus other attributes from different sources like Ensembl in 
case they exist, in case not we would like to still retrieve the local data and 
getting "no data" in those Ensembl attributes that do not exist for the 
selected local attributes. Is this possible?

The issue is that when I query only the local attributes (in this case the 
"affy id" attribute) the results only contain those "affy ids" that are also 
present on Ensembl. I would agree with this result if I would have included in 
the query attributes from the Ensembl mart but this is not the case. Then the 
question is the following: Is BioMart by default making the intersection 
between the two sources when creating a link between them? Is there a way to 
get the union instead of the intersection?

Thanks in advance,

--
Isaac Cano
Bioinformatics
Linkcare Health Services SL
C/Villarroel 170
08036 - Barcelona
Tel.: (+34)932 275 400, ext. 4182\4523
Mobile: (+34) 666 186 748
Fax: (+34) 932 275 455
[email protected]<mailto:[email protected]>

_______________________________________________
Users mailing list
[email protected]
https://lists.biomart.org/mailman/listinfo/users

Reply via email to