DESCRIPTION: Automatically updates dynamic_library_path when CDC is
enabled
fix : #7715
According to the documentation and `pg_settings`, the context of the
`citus.enable_change_data_capture` parameter is user.
However, changing this parameter — even as a superuser — doesn't work as
expected: while the initial copy phase works correctly, subsequent
change events are not propagated.
This appears to be due to the fact that `dynamic_library_path` is only
updated to `$libdir/citus_decoders:$libdir` when the server is restarted
and the `_PG_init` function is invoked.
To address this, I added an `EnableChangeDataCaptureAssignHook` that
automatically updates `dynamic_library_path` at runtime when
`citus.enable_change_data_capture` is enabled, ensuring that the CDC
decoder libraries are properly loaded.
Note that `dynamic_library_path` is already a `superuser`-context
parameter in base PostgreSQL, so updating it from within the assign hook
should be safe and consistent with PostgreSQL’s configuration model.
If there’s any reason this approach might be problematic or if there’s a
preferred alternative, I’d appreciate any feedback.
cc. @jy-min
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Co-authored-by: Hanefi Onaldi <Hanefi.Onaldi@microsoft.com>
Co-authored-by: ibrahim halatci <ihalatci@gmail.com>
SongYoungUk