Re: interval precision oddness

Peter Eisentraut <peter_e@gmx.net> writes:
> When you create a column with a plain "interval" column, the typmod is
> set to -1 and the information schema reports this as 6, because that's
> what the internal default value is (see _pg_datetime_precision
> function).  But when you create a column such as "interval year to
> month"), the typmod is actually the bit encoding of "year to month" in
> the higher 16 bits and 65535 in the lower 16 bits, and so the
> information schema reports the precision as 65535, whereas the actual
> behavior still corresponds to a precision of 6.

> I guess this could be seen as a reporting issue.  We could adjust
> _pg_datetime_precision to map 65535 to 6, just like -1 is mapped to 6.
> Or is there anything else wrong here?

No, it sounds like the information_schema function didn't get the memo
about what that meant.  See INTERVAL_FULL_RANGE, INTERVAL_FULL_PRECISION
macros and usage thereof, esp. intervaltypmodout.
        regards, tom lane