Re: Querying the schema for column widths - what syntax do I use?

From: Martijn van Oosterhout <kleptog(at)svana(dot)org>
To: Howard Wilkinson <howard(at)cohtech(dot)com>
Cc: Tino Wildenhain <tino(at)wildenhain(dot)de>, pgsql-general(at)postgresql(dot)org
Subject: Re: Querying the schema for column widths - what syntax do I use?
Date: 2008-02-22 15:58:36
Message-ID: 20080222155836.GF15579@svana.org
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

On Fri, Feb 22, 2008 at 11:38:33AM +0000, Howard Wilkinson wrote:
> The package is a DNS server originally hosted on top of a MySQL data
> base. I am extending it in a number of ways, but this particular need
> arises as I need to store some data (binary in nature) in a field that
> is part of the key for an index. The data is < 65536 in length. However,
> most of the time it is <<<<<<65536 e.g. 4 bytes. I also need to support
> backwards compatibility with the previous releases which had limited
> storage capacity in this field.

Just remember that if you're going to index the data that a btree index
will handle a maximum of 2700 *bytes* which, depending on your encoding
might be many less characters. This is independant of the maximum size
of the datatype.

How you deal with this depends on why exactly you want it indexed.

Have a nice day,
--
Martijn van Oosterhout <kleptog(at)svana(dot)org> http://svana.org/kleptog/
> Those who make peaceful revolution impossible will make violent revolution inevitable.
> -- John F Kennedy

In response to

Browse pgsql-general by date

  From Date Subject
Next Message Daniel Verite 2008-02-22 16:05:21 Re: Selecting large objects stored as bytea
Previous Message A.M. 2008-02-22 15:58:00 Re: Mac ordering with locales