Re: Efficient Boolean Storage

It is unintuitive to me that the low byte be padded. Shouldn't it be
the high byte?

JLL

Joe Conway wrote:
>
> Csaba Nagy wrote:
> > BTW, is or is not using Postgres a string to store the bit data types ? I
> > have seen a few people asking this on the list, but no straight answer as of
> > yet... the docs really don't mention this aspect.
>
> Use the source ;-)
>
> From varbit.c
>
> /*----------
> * attypmod -- contains the length of the bit string in bits, or for
> * varying bits the maximum length.
> *
> * The data structure contains the following elements:
> * header -- length of the whole data structure (incl header)
> * in bytes. (as with all varying length datatypes)
> * data section -- private data section for the bits data structures
> * bitlength -- length of the bit string in bits
> * bitdata -- bit string, most significant byte first
> *
> * The length of the bitdata vector should always be exactly as many
> * bytes as are needed for the given bitlength. If the bitlength is
> * not a multiple of 8, the extra low-order padding bits of the last
> * byte must be zeroes.
> *----------
> */
>
> Joe
>
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