Re: Thoughts on how to avoid a massive integer update. - Mailing list pgsql-general

From Rob Sargent
Subject Re: Thoughts on how to avoid a massive integer update.
Date
Msg-id 7171C32C-B8BC-4721-9938-8F6BA4E38BC7@gmail.com
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In response to Re: Thoughts on how to avoid a massive integer update.  ("David G. Johnston" <david.g.johnston@gmail.com>)
Responses Re: Thoughts on how to avoid a massive integer update.  ("David G. Johnston" <david.g.johnston@gmail.com>)
List pgsql-general


On May 8, 2020, at 2:37 PM, David G. Johnston <david.g.johnston@gmail.com> wrote:

On Fri, May 8, 2020 at 12:49 PM Rob Sargent <robjsargent@gmail.com> wrote:
Well as I said, I think you could add a column to info_table
alter table info_table add orig_id int;
update info_table set orig_id = info_table_sid;

update info_table set info_table_sid = 456 where info_table_sid = 456; 
 
huh? 

alter table data_table drop reference NOT SQL
alter table data_table make reference to info_table.orig_id NOT SQL

You don't seem to understand the requirement.  The data_table integer value must be changed - all you are doing is a convoluted column rename on the table holding the PK half of the relationship.

David J.

My understanding is the keys in the info_table need to change.  That causes the very expensive update in the update in the data tables. No? 



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