Re: Getting lengths of variable fields

Peter Eisentraut <peter_e@gmx.net> writes:
> Michelle Murrain writes:
>> Is there something I am missing? Is there a way to get the size of variable
>> length types using DBI/DBD::Pg, in particular, char() and varchar()?

> Normally, you'd use LENGTH or OCTET_LENGTH.  If you want to get the
> storage size on disk, you could add 4 to what you get as length, but this
> result seems to be of dubious value, especially with TOAST (compression,
> out-of-line storage).

What Michelle seems to want is the declared limit on field width, not
the actual width of any particular value.

This info is stored in the 'atttypmod' field of pg_attribute, but I
don't know whether DBD::Pg provides any handy interface to that.  You
might have to get down-and-dirty enough to select it directly out of
pg_attribute ...

            regards, tom lane