On 1 Jun 2007, at 16:06, Guðmundur Árni Þórisson wrote:
I'm starting to use MartBuilder for real now and slowly getting the
hang of things. I've managed to create some simple datasets without
problems (just works!), but when going into more complex things I am
stumbling. Specifically, I do not see how to tell MBuilder to do
certain complex multi-table joins to pull various pieces of data
together.
Here's an example of this sort of thing is genotype frequency data
I want to pull out of my database. Some tables hold data for filters
and/or attributes, others are merely linking tables:
Study->Experiment->Usedmarkerset->GenotypeFrequencyCluster-
>GenotypeFrequency->[couple more tables]
I see some indication of how MartBuilder is doing things when it has
created a dimension table out of two tables, and click 'Explain
table'. It's also doing something clever when I select multiple tables
in the 'Create datasets' dialog. But is this procedure entirely
automatic, offering no control beyond masking dimension tables *after*
MBuilder has created the dataset? How deep does it go, in terms of
following the PK-FK trail?
the algorithm follows the PK/FK and derived cardinalities. whenever it
hits 1:n or n:m it stops and creates a dm table
or in case of a dm table just stops.
I guess I'm hunting for a clue as to whether I can add tables to a
dataset semi-manually, one by one?
you can override the algorithm and make MBuilder to merge table
according to you wishes.
Not sure if available in 0.5 but definitely possible in 0.6 Richard
will tell you more about it
Or is it entirely a matter of telling MBuilder to do X number of
tables, and then sorting out the mess afterwards via mask/hide and so
on?
you can force it to merge tables regardless the algorithm.
a.
Mummi
PS I tried the 'Add restriction to table' and it's just wicked,
extremely useful! My particular use case is that I have an Experiment
table with different types of experiment-thingies: frequency
determination, association analysis etc. This function let's me easily
create seperate datasets for each!
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Gudmundur A. Thorisson, PhD student, Brookes lab
Department of Genetics
University of Leicester
University Road
Leicester, LE1 7RH, UK
E-mail: [EMAIL PROTECTED]
Tel: +44 (0)116 252-3055
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Arek Kasprzyk
EMBL-European Bioinformatics Institute.
Wellcome Trust Genome Campus, Hinxton,
Cambridge CB10 1SD, UK.
Tel: +44-(0)1223-494606
Fax: +44-(0)1223-494468
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