This release contains performance improvements and bug fixes since
the 2.14.2 release. We recommend that you upgrade at the next
available opportunity.
In addition, it includes these noteworthy features:
* Support `time_bucket` with `origin` and/or `offset` on Continuous Aggregate
* Compression improvements:
- Improve expression pushdown
- Add minmax sparse indexes when compressing columns with btree indexes
- Make compression use the defaults functions
- Vectorize filters in WHERE clause that contain text equality operators and LIKE expressions
**Deprecation warning**
* Starting on this release will not be possible to create Continuous Aggregate using `time_bucket_ng` anymore and it will be completely removed on the upcoming releases.
* Recommend users to [migrate their old Continuous Aggregate format to the new one](https://docs.timescale.com/use-timescale/latest/continuous-aggregates/migrate/) because it support will be completely removed in next releases prevent them to migrate.
* This is the last release supporting PostgreSQL 13.
**For on-premise users and this release only**, you will need to run [this SQL script](https://github.com/timescale/timescaledb-extras/blob/master/utils/2.15.X-fix_hypertable_foreign_keys.sql) after running `ALTER EXTENSION`. More details can be found in the pull request [#6786](https://github.com/timescale/timescaledb/pull/6797).
**Features**
* #6382 Support for time_bucket with origin and offset in CAggs
* #6696 Improve defaults for compression segment_by and order_by
* #6705 Add sparse minmax indexes for compressed columns that have uncompressed btree indexes
* #6754 Allow DROP CONSTRAINT on compressed hypertables
* #6767 Add metadata table `_timestaledb_internal.bgw_job_stat_history` for tracking job execution history
* #6798 Prevent usage of deprecated time_bucket_ng in CAgg definition
* #6810 Add telemetry for access methods
* #6811 Remove no longer relevant timescaledb.allow_install_without_preload GUC
* #6837 Add migration path for CAggs using time_bucket_ng
* #6865 Update the watermark when truncating a CAgg
**Bugfixes**
* #6617 Fix error in show_chunks
* #6621 Remove metadata when dropping chunks
* #6677 Fix snapshot usage in CAgg invalidation scanner
* #6698 Define meaning of 0 retries for jobs as no retries
* #6717 Fix handling of compressed tables with primary or unique index in COPY path
* #6726 Fix constify cagg_watermark using window function when querying a CAgg
* #6729 Fix NULL start value handling in CAgg refresh
* #6732 Fix CAgg migration with custom timezone / date format settings
* #6752 Remove custom autovacuum setting from compressed chunks
* #6770 Fix plantime chunk exclusion for OSM chunk
* #6789 Fix deletes with subqueries and compression
* #6796 Fix a crash involving a view on a hypertable
* #6797 Fix foreign key constraint handling on compressed hypertables
* #6816 Fix handling of chunks with no contraints
* #6820 Fix a crash when the ts_hypertable_insert_blocker was called directly
* #6849 Use non-orderby compressed metadata in compressed DML
* #6867 Clean up compression settings when deleting compressed cagg
* #6869 Fix compressed DML with constraints of form value OP column
* #6870 Fix bool expression pushdown for queries on compressed chunks
**Thanks**
* @brasic for reporting a crash when the ts_hypertable_insert_blocker was called directly
* @bvanelli for reporting an issue with the jobs retry count
* @djzurawsk For reporting error when dropping chunks
* @Dzuzepppe for reporting an issue with DELETEs using subquery on compressed chunk working incorrectly.
* @hongquan For reporting a 'timestamp out of range' error during CAgg migrations
* @kevcenteno for reporting an issue with the show_chunks API showing incorrect output when 'created_before/created_after' was used with time-partitioned columns.
* @mahipv For starting working on the job history PR
* @rovo89 For reporting constify cagg_watermark not working using window function when querying a CAgg
