Date: Wed, 3 Nov 2021 10:07:55 -0400
From: Bruce Momjian <bruce@momjian.us>
To: grega.jesih@gmail.com, pgsql-docs@lists.postgresql.org
Subject: Re: text fields and performance for ETL
Message-ID: <20211103140755.GD5273@momjian.us>
References: <163594615980.678.1904941309603792278@wrigleys.postgresql.org>
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On Wed, Nov  3, 2021 at 01:29:19PM +0000, PG Doc comments form wrote:
> The following documentation comment has been logged on the website:
> 
> Page: https://www.postgresql.org/docs/9.6/datatype-character.html
> Description:
> 
> Text field is a field that is intended for very big texts. 
> Performance within Postgres database is commented to be the same as for
> normal varchar. 
> 
> But performance in ETL processes related to such data type is decreased
> dramatically, because any process that takes this kind of data needs to
> calculate its size on a row level and cannot take bigger chunks of data
> based on max size. 
> 
> So the conclusion would be to use an appropriate character length that
> reflects max string size.

I have no idea what you are saying above.  There is no additional
overhead for TEXT vs VARCHAR() in Postgres so it seems like an overhead
in applications.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

  If only the physical world exists, free will is an illusion.