Clean up the table schema to get rid of legacy tables and functionality
that makes it more difficult to provide an upgrade path.
Notable changes:
* Get rid of legacy tables and code
* Simplify directory structure for SQL code
* Simplify table hierarchy: remove root table and make chunk tables
* inherit directly from main table
* Change chunk table suffix from _data to _chunk
* Simplify schema usage: _timescaledb_internal for internal functions.
* _timescaledb_catalog for metadata tables.
* Remove postgres_fdw dependency
* Improve code comments in sql code
Previously, each test set their own (although mostly the same)
configuration for log output and error verbosity. This is now set
globally in the test runner so that tests only need to set these
configuration parameters if they need to override the defaults. The
log verbosity is also reduced so that errors aren't generated with the
line number of the source file that output the error. Line numbers in
the output can break tests when upgrading to a new PostgreSQL version
that outputs a different line number.
Previously, the planner used a direct query via the SPI interface to
retrieve metadata info needed for query planner functions like query
rewriting. This commit updates the planner to use our caching system.
This is a performance improvement for pretty much all operations,
both data modifications and queries.
For hypertables, this added a cache keyed by the main table OID and
added negative entries (because the planner often needs to know if a
table is /not/ a hypertable).
This patch refactors the insert path to use insert triggers
instead of a temporary copy table. The copy table previously
served as an optimization for big batches where the cost of
inserting tuple-by-tuple into chunks was amortized by inserting
all tuples for a specific chunk in one insert. However, to avoid
deadlocks the tuples also had to inserted in a specific chunk
order, requiring adding an index to the copy table.
With trigger insertion, tuples are instead collected over a batch
into a sorting state, which is sorted in an "after" trigger. This
removes the overhead of the copy table and index. It also provides
a fast-path for single-tuple batches that avoids doing sorting
altogether.
