Re: Detecting schema changes via WAL logs

On 19.02.22 17:42, Cal Mitchell wrote:
> Hello everyone,
>
> I’m building an open-source data integration tool (SQLpipe) and am now
> trying to incorporate CDC into the product.
>
> Is it possible to detect when schema changes happen via the WAL? The WAL
> doesn’t have to tell me /what/ was changed, it just needs to tell me
> /when/ something changed.
>
> For example, anytime I run create table or some other DDL command, there
> is a begin and commit message in the log, with nothing in between. If
> there aren’t any other operations that create such “empty” logs, it
> seems possible to just re-scan the tables that are being synced for
> schema changes whenever one of these logs is encountered.

I remember having seen a similar question recently here - that is
detecting schema changes.

Also I think having seen WAL to SQL scripts somewhere.

I might be wrong on both accounts, but maybe you want to review the last
few months of list archives if you haven't done so already and maybe
check postgres' Debian package repository if there aren't WAL to SQL
scripts somewhere.

As I said, this is what my fuzzy in-brain SQL returns so please don't
SIGKILL me if my query was too fuzzy indeen.
*t