MonetDB: SciQL-2 - handle non-rectangular array tiles
Y.Zhang at cwi.nl
Thu Aug 15 14:25:31 CEST 2013
>> - disable the check on (max - min + 1 = size), since it only holds for
>> stepsize = 1.
>> maybe we should just remove this check, since we don't have step size in
>> tiling aggr impl. functions, do we?
> IMHO, our current tiled aggregation implementation inherently assumes (and thus requires) that all dimensions of the given array have step-size == 1. Since ARRAYtiles*() does not get the step sizes of the given array as parameters, the check (max - min + 1 = size) was/is IMHO the only way to check/ensure that we are indeed working on an array where all dimensions have step-size == 1.
Ok. I don't recall this assumption, so I was testing the code with a small array with step-size > 1, which triggers the assertion. After having disabled this check, the query actually returns correct results. Time to check this assumption, maybe it's easy to get rid of it.
>> now we can get rid of the workarounds
>> more tests needed...
> Indeed --- I'll resume me test tonight or tomorrow …
I tested the with a tiny array to see that e.g., computing SUM of a diagonal line works correctly.
I rerun the BSM queries, with the real implementation of clump_4connected_1. The queries finished without errors, but when checking the found fires, I only got a black picture...
I'll do more test this afternoon.
> | Stefan.Manegold at CWI.nl | DB Architectures (DA) |
> | www.CWI.nl/~manegold/ | Science Park 123 (L321) |
> | +31 (0)20 592-4212 | 1098 XG Amsterdam (NL) |
More information about the developers-list