Patch 0001 adds a new event trigger type that can be fired, but it's missing documentation and its own tests. (I think part of the docs are in 0002, but that seems to be only the changes to the supported operations table, without any other explanation for it in sect1 event-trigger-definition, and examples showing it at work). Adding a new event trigger type is quite a major thing because it's user visible, so a commit that adds that should be self-contained. Users will want to use it for other things as soon as it's in, for reasons other than what you're adding it for. This also means that you'll want to keep other things separate, such as adding AlterTableStmt->table_like and the move of structs from event_trigger.c to event_trigger.h ... and is EventTriggerAlterTypeStart/End necessary in 0001 as well, or should it be separate?
(I find patch series as single .tar.gz not very friendly. I think compression is okay, but perhaps compress each patch separately.) -- Álvaro Herrera Breisgau, Deutschland — https://www.EnterpriseDB.com/