Re:

Francisco Reyes wrote:
> On the FAQ we have:
>
> CHAR() is best when storing strings that are usually the
> same length.  VARCHAR() is best when storing variable-length strings,
> but you want to limit how long a string can be.  TEXT is for strings
> of unlimited length, maximum 1 gigabyte.  BYTEA is for storing
> binary data, particularly values that include NULL bytes.
>
>
> How much space does "NULL" takes on a varchar.

Zero space.  We have a bitmask of NULL columns for every row.

> I have a table where possibly less than 40% of the records will have a
> value. I am wondering if I should go with a second table for those that
> have the values or if NULL is small enough that it won't be much an
> overhead for the possibly 60% instances when the column would be empty.

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