Re: Column Filtering in Logical Replication

On 2022-Jan-06, Amit Kapila wrote:

> Considering this, don't we need to deal with "For All Tables" and "For
> All Tables In Schema .." Publications in this query? The row filter
> patch deal with such cases. The row filter patch handles the NULL case
> via C code which makes the query relatively simpler.

Yes. I realized after sending that email that the need to handle schema
publications would make a single query very difficult, so I ended up
splitting it again in two queries, which is what you see in the latest
version submitted.

> I am not sure if the same logic can be used here but having a simple
> query here have merit that if we want to use a single query to fetch
> both column and row filters then we should be able to enhance it
> without making it further complicated.

I have looked the row filter code a couple of times to make sure we're
somewhat compatible, but didn't look closely enough to see if we can
make the queries added by both patches into a single one.

> Shouldn't we try to have a behavior similar to the row filter patch
> for this case? The row filter patch behavior is as follows: "If your
> publication contains a partitioned table, the publication parameter
> publish_via_partition_root determines if it uses the partition row
> filter (if the parameter is false, the default) or the root
> partitioned table row filter. During initial tablesync, it doesn't do
> any special handling for partitions.

I'll have a look.

Thanks for looking!

--
Álvaro Herrera Valdivia, Chile — https://www.EnterpriseDB.com/