Attaching tablespaces to hypertables is now handled
in native code, with improved permissions checking and
caching of tablespaces in the Hypertable data object.
TimescaleDB cache invalidation happens as a side effect of doing a
full SQL statement (INSERT/UPDATE/DELETE) on a catalog table (via
table triggers). However, triggers aren't invoked when using
PostgreSQL's internal catalog API for updates, since PostgreSQL's
catalog tables don't have triggers that require full statement
parsing, planning, and execution.
Since we are now using the regular PostgreSQL catalog update API for
some TimescaleDB catalog operations, we need to do cache invalidation
also on such operations.
This change adds cache invalidation when updating catalogs using the
internal (C) API and also makes the cache invalidation more fine
grained. For instance, caches are no longer invalidated on some
INSERTS that do not affect the validity of objects already in the
cache, such as adding a new chunk.
This is part of the ongoing effort to simplify the metadata tables and
removing any triggers on them that cause side effects.
This change includes the following:
- Remove the on_change_hypertable() trigger on the hypertable catalog
table.
- Remove the TRUNCATE blocking triggers on all metadata tables. If
we think such blocking is important, we should do this in an
event trigger or the processUtility hook.
- Put all SQL files in a single load_order.txt instead of splitting
across three distinct files. Now all SQL files are included in
update scripts as well for simplicity and consistency.
- As a result of removing triggers and related functions, the
setup_main() and restore_timescaledb() functions are no longer
needed. This also further simplifies the database restore process
as calling restore_timescaledb() is no longer needed (or possible).
- Refactor create_hypertable_row() to do more validation before
allocating a new hypertable ID. This avoids incrementing the serial
ID unnecessarily in case some validations fail.
SQL code is now split into setup, functions, and init files to
allow a subset to be run when the extension is updated. During
build, an update script is now also generated.
Previously, the extension could end up in a bad state if it
was dropped as part of a cascade. This PR fixes that by
checking explicitly for the presence of the proxy table
to make sure we are not in the middle of an extension
drop. Fixes#73.
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
