To increase schema security we do not want to mix our own internal
objects with user objects. Since chunks are created in the
_timescaledb_internal schema our internal functions should live in
a different dedicated schema. This patch make the necessary
adjustments for the following functions:
- policy_compression_check(jsonb)
- policy_compression_execute(integer,integer,anyelement,integer,boolean,boolean)
- policy_compression(integer,jsonb)
- policy_job_error_retention_check(jsonb)
- policy_job_error_retention(integer,jsonb)
- policy_recompression(integer,jsonb)
- policy_refresh_continuous_aggregate_check(jsonb)
- policy_refresh_continuous_aggregate(integer,jsonb)
- policy_reorder_check(jsonb)
- policy_reorder(integer,jsonb)
- policy_retention_check(jsonb)
- policy_retention(integer,jsonb)
Instead of using a user name to register the owner of a job, we use
regrole. This allows renames to work properly since the underlying OID
does not change when the owner name changes.
We add a check when calling `DROP ROLE` that there is no job with that
owner and generate an error if there is.
Currently, the next start of a scheduled background job is
calculated by adding the `schedule_interval` to its finish
time. This does not allow scheduling jobs to execute at fixed
times, as the next execution is "shifted" by the job duration.
This commit introduces the option to execute a job on a fixed
schedule instead. Users are expected to provide an initial_start
parameter on which subsequent job executions are aligned. The next
start is calculated by computing the next time_bucket of the finish
time with initial_start origin.
An `initial_start` parameter is added to the compression, retention,
reorder and continuous aggregate `add_policy` signatures. By passing
that upon policy creation users indicate the policy will execute on
a fixed schedule, or drifting schedule if `initial_start` is not
provided.
To allow users to pick a drifting schedule when registering a UDA,
an additional parameter `fixed_schedule` is added to `add_job`
to allow users to specify the old behavior by setting it to false.
Additionally, an optional TEXT parameter, `timezone`, is added to both
add_job and add_policy signatures, to address the 1-hour shift in
execution time caused by DST switches. As internally the next start of
a fixed schedule job is calculated using time_bucket, the timezone
parameter allows using timezone-aware buckets to calculate
the next start.
This commit gives more visibility into job failures by making the
information regarding a job runtime error available in an extension
table (`job_errors`) that users can directly query.
This commit also adds an infromational view on top of the table for
convenience.
To prevent the `job_errors` table from growing too large,
a retention job is also set up with a default retention interval
of 1 month. The retention job is registered with a custom check
function that requires that a valid "drop_after" interval be provided
in the config field of the job.
