Re: Errors with schema migration and logical replication — expected?

On 12/9/18 8:03 AM, Mike Lissner wrote:
> 
>     The above seems to be the crux of the problem, how did NULL get into
>     the
>     column data?
> 
> 
> I agree. My queries are generated by Django (so I never write SQL 
> myself), but:
> 
>   - the column has always been NOT NULL for its entire lifetime

The lifetime being since the migration did this?:

ALTER TABLE "search_docketentry" ADD COLUMN "recap_sequence_number" 
varchar(50) DEFAULT '' NOT NULL;
ALTER TABLE "search_docketentry" ALTER COLUMN "recap_sequence_number" 
DROP DEFAULT;

Also does the column recap_sequence_number appear in any other tables. 
Just wondering if the error was on another table?


>   - we don't send *any* SQL commands to the replica yet, so that's not a 
> factor (for now it's just a live backup)
>   - the publisher now has a NOT NULL constraint on that column. I never 
> had to clear out null values to put it in place. I assume that if that 

This part confuses me. You seem to imply that the column existed before 
the migration and you just added a NOT NULL constraint. The migration 
shows the column being created with a NOT NULL constraint.

> column ever had a null value and I tried to run a DDL to add a null 
> constraint, the DDL would have failed, right?
> 
> Something feels wrong here, the more I think about it.

A start would be to figure out what generated?:

failing row contains (48064261, 2018-12-07 04:48:40.388377+00, 
2018-12-07 04:48:40.388402+00, null, 576, , 4571214, null, null)


-- 
Adrian Klaver
adrian.klaver@aklaver.com