In the session timescaledb_post_restore() was called the value for
timescaledb.restoring might not be changed because the reset_val
for the GUC was still on. We have to use explicit SET in this
session to adjust the GUC.
Postgres will prepend pg_temp to the effective search_path if it
is not present in the search_path. While pg_temp will never be
used to look up functions or operators unless explicitly requested
pg_temp will be used to look up relations. Putting pg_temp in
search_path makes sure objects in pg_temp will be considered last
and pg_temp cannot be used to mask existing objects.
This patch locks down search_path in extension install and update
scripts to only contain pg_catalog, this requires that any reference
in those scripts is fully qualified. Additionally we add explicit
create commands to all update scripts for objects added to the
public schema. This change will make update scripts fail if a
function with identical signature already exists when installing
or upgrading instead reusing the existing object.
Setting the `timescaledb.restoring` guc explicitly to 'off'
for the db meant that the setting got exported in `pg_dumpall`
and some other cases where that setting would then conflict
with the setting set by the pre_restore function causing it to
be overridden and causing errors on restore. This changes to
`RESET` so that instead it will take the system default and not
be dumped separately as an override.
There was a race condition between the post_restore function
restarting the background worker and the setting of the
restoring flag to "off". If the worker started before the
change to the restoring flag had been committed, it would not
see the change and then die because the worker should exit
when the db is in a restoring state. This modifies the
post_restore function to use a restart instead of a start
so that it waits on the commit to start up. It also adds
logic to the entrypoint to reload config changes caused
by an `ALTER DATABASE SET` command. These changes are
normally only seen at connection startup but we have to
wait until after our lock on the modifying transaction is
released to know whether we should adopt them.
When restoring a database, people would encounter errors if
the restore happened after telemetry has run. This is because
a 'exported_uuid' field would then exist and people would encounter
a "duplicate key value" when the restore tried to overwrite it.
We fix this by moving this metadata to a different key
in pre_restore and trying to move it back in post_restore.
If the restore create an exported_uuid, that restored
value is used and the moved version is simply deleted
We also remove the error redirection in restore so that errors
will show up in tests in the future.
Fixes#1409.
These functions improve usability and take all the proper steps to
set restoring on/off (and stop/start background workers in the process)
and to set the license key via a function rather than a guc modification.
