Re: Column Filtering in Logical Replication

On 2/16/22 01:33, Alvaro Herrera wrote:
> On 2022-Feb-16, Tomas Vondra wrote:
>
>> Here's an updated version of the patch, rebased to current master. Parts
>> 0002 and 0003 include various improvements based on review by me and another
>> one by Peter Smith [1].
>
> Thanks for doing this!
>
>> 1) partitioning with pubviaroot=true
>
> I agree that preventing the inconsistencies from happening is probably
> the best.
>
>> 2) merging multiple column filters
>>
>> When the table has multiple column filters (in different publications), we
>> need to merge them. Which works, except that FOR ALL TABLES [IN SCHEMA]
>> needs to be handled as "has no column filter" (and replicates everything).
>
> Agreed.
>
>> 3) partitioning with pubivaroot=false
>>
>> When a partitioned table is added with (pubviaroot=false), it should not be
>> subject to column filter on the parent relation, which is the same behavior
>> used by the row filtering patch.
>
> You mean each partition should define its own filter, or lack of filter?
> That sounds reasonable.
>

If the partition is not published by the root, it shouldn't use the
filter defined on the root. I wonder what should happen to the filter
defined on the partition itself. I'd say

pubviaroot=false -> use filter defined on partition (if any)

pubviaroot=true -> use filter defined on root (if any)

I wonder what the row filter patch is doing - we should probably follow
the same logic, if only to keep the filtering stuff consistent.

regards

--
Tomas Vondra
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