Horton

Re: Domains vs data types

Greg Sabino Mullane <htamfids@gmail.com>

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From: Greg Sabino Mullane <htamfids@gmail.com>
To: Ertan Küçükoglu <ertan.kucukoglu@gmail.com>
Cc: pgsql-general@lists.postgresql.org
Date: 2025-08-20T16:12:25Z
Lists: pgsql-general 
On Wed, Aug 20, 2025 at 12:48 AM Ertan Küçükoglu <ertan.kucukoglu@gmail.com>
wrote:

> Does the second table have any technical advantage/disadvantage over plain
> data type definition?
> Less metadata in memory? High metadata in memory? Less/increased disk
> space?
>

Same disk space. No disadvantage other than confusing your users, and any
performance differences will be so minor as to be unmeasurable. (my two
cents: domains are best when the data type is complex AND shared across
multiple tables. Even then I tend to avoid them.)

Cheers,
Greg

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