From: Bruce Momjian <maillist@candle.pha.pa.us>
Message-Id: <199804231645.MAA26157@candle.pha.pa.us>
Subject: Re: [HACKERS] Re: [INTERFACES] retrieving varchar size
To: hannu@trust.ee (Hannu Krosing)
Date: Thu, 23 Apr 1998 12:45:42 -0400 (EDT)
Cc: byronn@insightdist.com, pgsql-hackers@postgreSQL.org,
	pgsql-interfaces@postgreSQL.org
In-Reply-To: <353F6BBC.50EB8C99@sid.trust.ee> from "Hannu Krosing" at Apr 23,
	98 07:26:36 pm
MIME-Version: 1.0
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> 
> Byron Nikolaidis wrote:
> > 
> > Hello,
> > 
> > I was wondering if it would be possible, in the Postgres backend, to
> > send back the defined column size for the varchar data type (and
> > possibly the char() type, i.e., bpchar) on a query?  Currently, it just
> > sends back -1 for the size, which makes it difficult in the frontend
> > (i.e., odbc driver) to determine what the size of the column is.
> 
> While the right solution to this is of course getting the size from 
> backend, there exists a workaround now (assuming that the query is not 
> too expensive). While ASCII cursors always hide the varchar sizes, 
> binary ones return the size in actual data (by zero-padding the 
> returned data to max size), so one can determine the actual max 
> sizes by opening the query in binary cursor and then examining 
> enough records to get one non-null field for each varchar field.

As of 6.3, this is only true of char() fields.  Varchar() is now
variable length.

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