Our code occasionally mentions max_bucket_width. However, in practice, there is
no such thing. For fixed-sized buckets, bucket_width and max_bucket_width are
always the same, while for variable-sized buckets bucket_width is not used at
all (except the fact that it equals -1 to indicate that the bucket size is
variable).
This patch removes any use of max_bucket_width, except for arguments of:
- _timescaledb_internal.invalidation_process_hypertable_log()
- _timescaledb_internal.invalidation_process_cagg_log()
The signatures of these functions were not changed for backward compatibility
between access and data nodes, which can run different versions of TimescaleDB.
This patch allows using time_bucket_ng("N month", ...) in CAGGs. Users can also
specify years, or months AND years. CAGGs on top of distributed hypertables
are supported as well.
Add support for continuous aggregates for distributed hypertables by
allowing a continuous aggregate to read from a distributed hypertable
so that the continuous aggregate is on the access node while the
hypertable data is on the data nodes.
For distributed hypertables, both the hypertable and continuous
aggregate invalidation log are kept on the data nodes and the refresh
window is computed at refresh time on each data node. Since the
continuous aggregate materialization hypertable is not present on the
data nodes, the invalidation log was extended to allow using a
non-local hypertable id on the data nodes. This means that you cannot
create continuous aggregates on the data nodes since those could clash
with continuous aggregates on the access node.
Some utility statements added entries to the invalidation logs
directly (truncating chunks and hypertables, as well as dropping
individual chunks), so to handle this case, internal functions were
added to allow logging invalidation on the data nodes from the access
node.
The commit also includes some fixes to memory context usage that
caused crashes for invalidation triggers and also disable per data
node queries during refresh since that would otherwise generate an
exception.
Fixes#3435
Co-authored-by: Mats Kindahl <mats@timescale.com>
