Search Postgresql Archives

Re: Help with large delete

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 2022-04-16 08:25:56 -0500, Perry Smith wrote:
> Currently I have one table that mimics a file system.  Each entry has
> a parent_id and a base name where parent_id is an id in the table that
> must exist in the table or be null with cascade on delete.
> 
> I’ve started a delete of a root entry with about 300,000 descendants.
> The table currently has about 22M entries and I’m adding about 1600
> entries per minute still.  Eventually there will not be massive
> amounts of entries being added and the table will be mostly static.
> 
> I started the delete before from a terminal that got detached.  So I
> killed that process and started it up again from a terminal less
> likely to get detached.˘
> 
> My question is basically how can I make life easier for Postgres?

Deleting 300k rows doesn't sound that bad. Neither does recursively
finding those 300k rows, although if you have a very biased distribution
(many nodes with only a few children, but some with hundreds of
thousands or even millions of children), PostgreSQL may not find a good
plan.

So as almost always when performance is an issue:

* What exactly are you doing?
* What is the execution plan?
* How long does it take?

        hp

-- 
   _  | Peter J. Holzer    | Story must make more sense than reality.
|_|_) |                    |
| |   | hjp@xxxxxx         |    -- Charles Stross, "Creative writing
__/   | http://www.hjp.at/ |       challenge!"

Attachment: signature.asc
Description: PGP signature


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Postgresql Jobs]     [Postgresql Admin]     [Postgresql Performance]     [Linux Clusters]     [PHP Home]     [PHP on Windows]     [Kernel Newbies]     [PHP Classes]     [PHP Databases]     [Postgresql & PHP]     [Yosemite]

  Powered by Linux