Re: Effects of dropping a large table - Mailing list pgsql-general

From Ron
Subject Re: Effects of dropping a large table
Date
Msg-id f1815a29-4ef4-bb25-0c20-d3973bf7bb2b@gmail.com
Whole thread Raw
In response to Re: Effects of dropping a large table  ("Peter J. Holzer" <hjp-pgsql@hjp.at>)
List pgsql-general
On 7/23/23 05:27, Peter J. Holzer wrote:
> On 2023-07-23 06:09:03 -0400, Gus Spier wrote:
>> Ah! Truncating a table does not entail all of WAL processes. From the
>> documentation, "TRUNCATE quickly removes all rows from a set of tables. It has
>> the same effect as an unqualified DELETE on each table, but since it does not
>> actually scan the tables it is faster. Furthermore, it reclaims disk space
>> immediately, rather than requiring a subsequent VACUUM operation. This is most
>> useful on large tables." https://www.postgresql.org/docs/14/sql-truncate.html
> I assumed that by "deleting the now empty table" you meant DROPing it.
> (Performing a «DELETE FROM t» just after a «TRUNCATE t» would obviously
> be pointless).
>
> So let me rephrase the question:
>
> What's the advantage of
>
>      TRUNCATE t
>      DROP t
>
> over just
>
>      DROP t

Catalog or serialization locking?  (I don't know; just asking.)

-- 
Born in Arizona, moved to Babylonia.



pgsql-general by date:

Previous
From: "Peter J. Holzer"
Date:
Subject: Re: Effects of dropping a large table
Next
From: jian he
Date:
Subject: pageinspect bt_page_items doc