Hi, perhaps you guys can help me with this. we have 2 tables: * gf_data: 2 columns (gene_family id`s and gene_id`s) . This table has about 500k rows * annotation: lots of columns, but we only need the ones with the gene_id`s and the species. This table has about 300k rows. We now need a couple of things: * For each species, we need a count of genes that are in gene_families with a size larger than 1 * For each species, we need a count of gene_families. Now, I've tried already a lot, but run into the problem of having to use either joins or nested queries, which do not really scale well apparently :s I thought about creating a view (by appending the gene_family into the annotation table), but it's been such a long time i've done this that I cannot remember whether this will be any help at all. So, any suggestions? Michiel PS: I'll think about a price for the winner :) -- ================================================================== Michiel Van Bel PhD student Tel:+32 (0)9 331 36 95 fax:+32 (0)9 3313809 VIB Department of Plant Systems Biology, Ghent University Technologiepark 927, 9052 Gent, BELGIUM mibel@psb.ugent.be http://www.psb.ugent.be ==================================================================