Re: Getting lengths of variable fields

Tom Lane wrote:
>
> 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
>
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Hi Tom,

When I query the pg_attribute table to get the limit on a specific field
I get more than one row, because I use the same field name in few
tables.
However each row has different  "attrelid", I suppose that means that
every
table has its one unique "attrelid". My question is how do I find out
the
"attrelid" if I only know that table name??

That's the only thing that keeps me from getting max field limit for a
specific
field in a specific table...


Regards,
Boulat Khakimov


--
Nothing Like the Sun