On Sun, Oct 22, 2006 at 06:24:43PM +0200, Alex Mayrhofer wrote: > Hi, > > Two short questions: > > 1) What storage size does the "bit(n)" data type have? Is it one byte per 8 > bits (plus a "length" byte)? I didn't find this in neither the docs nor the > list archives ... It'll be a varlena structure, see backend/utils/adt/varbit.c. So 4 bytes + space needed for bits. > 2) Additionally, how much storage space does a functional index which > returns "boolean" approx. take? Will it be a bitmap? A boolean is one byte, plus whatever overhead is associated with the index. > Reason: i need to add some flags to a row, and i don't want to spend an > entire byte per flag on a "boolean" column (even worse, new flags could > probably be added in the future) - would it make sense to use > a bitstring, together with a functional index on any "interesting" bit in > that case? I'd say give it a shot. Seems reasonable. Have a nice day, -- Martijn van Oosterhout <kleptog@xxxxxxxxx> http://svana.org/kleptog/ > From each according to his ability. To each according to his ability to litigate.
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