public inbox for [email protected]
help / color / mirror / Atom feedFrom: Tom Lane <[email protected]>
To: [email protected]
Cc: [email protected]
Subject: Re: What does "Table rewrite" mean?
Date: Fri, 19 Jan 2018 11:33:43 -0500
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
References: <[email protected]>
=?utf-8?q?PG_Doc_comments_form?= <[email protected]> writes:
> What does a table rewrite do? Does it drop and recreate the table?
> Everywhere I look people describe it with fear and trepedation as if it was
> some catastrophically dangerous operation to perform. What is it?
It means reading the whole table and writing it out in some modified
form (for instance, with some column transformed into a new datatype).
It's not "dangerous" in any way ... but if you've got many GB of data in
the table and you can't afford to have the table locked for a long time,
then it's something to avoid.
regards, tom lane
view thread (5+ messages) latest in thread
reply
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: [email protected]
Cc: [email protected], [email protected], [email protected]
Subject: Re: What does "Table rewrite" mean?
In-Reply-To: <[email protected]>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox