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List:       postgresql-general
Subject:    Re: DB migration : Sybase to Postgres
From:       Ron <ronljohnsonjr () gmail ! com>
Date:       2023-05-26 14:03:36
Message-ID: 0b636573-472e-f129-c759-71a311b45fd6 () gmail ! com
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On 5/26/23 08:38, Peter J. Holzer wrote:
> On 2023-05-25 08:10:42 -0500, Ron wrote:
>> (You can create the FKs ahead of time, but use the NOT VALID clause; then,
>> after data is loaded do ALTER TABLE ... VALIDATE CONSTRAINT.)
> I don't think this will work:
>
> | Normally, [ADD CONSTRAINT] will cause a scan of the table to verify
> | that all existing rows in the table satisfy the new constraint. But if
> | the NOT VALID option is used, this potentially-lengthy scan is
> | skipped. The constraint will still be enforced against subsequent
> | inserts or updates
> (https://www.postgresql.org/docs/current/sql-altertable.html)

I was probably thinking of tables with existing data.

-- 
Born in Arizona, moved to Babylonia.


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