David G Johnston <david.g.johnston@xxxxxxxxx> writes: > Shida Sato wrote >> Why is there limit on the number of cube dimensions? >> From the docs: http://www.postgresql.org/docs/9.4/static/cube.html > "To make it harder for people to break things, there is a limit of 100 on > the number of dimensions of cubes. This is set in cubedata.h if you need > something bigger." > Thus the limit is indeed arbitrary - though if you decide to recompile to > increase that limit your expectations should be sufficient tempered since > likely few (if any) people are using cubes with 100 times the default limit > number of dimensions. Just offhand, it seems like that limit is doing a couple of things: * Protecting against overflow in memory allocation requests. In theory we could raise the limit to something near MaxAllocSize/(sizeof(double)*2) without breaking this. * Protecting against locking up the server if there are slow (O(N^2) or worse) algorithms in any of the cube functions. Before considering a proposal to raise the default value I'd want to see some investigation of the second point. regards, tom lane -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
