This release introduces the ability to add secondary indexes to the columnstore, improves group by and filtering performance through columnstore vectorization, and contains the highly upvoted community request of transition table support. We recommend that you upgrade at the next available opportunity.
Highlighted features in TimescaleDB v2.18.0
- The ability to add secondary indexes to the columnstore through the new hypercore table access method.
- Significant performance improvements through vectorization (
SIMD) for aggregations using a group by with one column and/or using a filter clause when querying the columnstore.
- Hypertables support triggers for transition tables, which is one of the most upvoted community feature requests.
- Updated methods to manage Timescale's hybrid row-columnar store (hypercore) that highlight the usage of the columnstore which includes both an optimized columnar format as well as compression.
Dropping support for Bitnami images
After the recent change in Bitnamiβs LTS support policy, we are no longer building Bitnami images for TimescaleDB. We recommend using the official TimescaleDB Docker image
Deprecation Notice
We are deprecating the following parameters, functions, procedures and views which are replaced by the new options listed below. They will be removed with the next major release of TimescaleDB, 3.0, which is not yet in the roadmap. We're providing ample notice to give you time to make the required changes.
| Deprecated | Replacement | Type |
| --- | --- | --- |
| decompress_chunk | convert_to_rowstore | Procedure |
| compress_chunk | convert_to_columnstore | Procedure |
| add_compression_policy | add_columnstore_policy | Function |
| remove_compression_policy | remove_columnstore_policy | Function |
| hypertable_compression_stats | hypertable_columnstore_stats | Function |
| chunk_compression_stats | chunk_columnstore_stats | Function |
| hypertable_compression_settings | hypertable_columnstore_settings | View |
| chunk_compression_settings | chunk_columnstore_settings | View |
| compression_settings | columnstore_settings | View |
| timescaledb.compress | timescaledb.enable_columnstore | Parameter |
| timescaledb.compress_segmentby | timescaledb.segmentby | Parameter |
| timescaledb.compress_orderby | timescaledb.orderby | Parameter |
Features
* #7341: Vectorized aggregation with grouping by one fixed-size by-value compressed column (such as arithmetic types).
* #7104: Hypercore table access method.
* #6901: Add hypertable support for transition tables.
* #7482: Optimize recompression of partially compressed chunks.
* #7458: Support vectorized aggregation with aggregate filter clauses that are also vectorizable.
* #7433: Add support for merging chunks.
* #7271: Push down order by in real-time continuous aggregate queries.
* #7455: Support drop not null on compressed hypertables.
* #7295: Support alter table set access method on hypertable.
* #7411: Change parameter name to enable hypercore table access method.
* #7436: Add index creation on order by columns.
* #7443: Add hypercore function and view aliases.
* #7521: Add optional force argument to refresh_continuous_aggregate.
* #7528: Transform sorting on time_bucket to sorting on time for compressed chunks in some cases.
* #7565: Add hint when hypertable creation fails.
* #7390: Disable custom hashagg planner code.
* #7587: Add include_tiered_data parameter to add_continuous_aggregate_policy API.
* #7486: Prevent building against PostgreSQL versions with broken ABI.
* #7412: Add GUC for the hypercore_use_access_method default.
* #7413: Add GUC for segmentwise recompression.
Bugfixes
* #7378: Remove obsolete job referencing policy_job_error_retention.
* #7409: Update bgw_job table when altering procedure.
* #7410: Fix the aggregated compressed column not found error on aggregation query.
* #7426: Fix datetime parsing error in chunk constraint creation.
* #7432: Verify that the heap tuple is valid before using.
* #7434: Fix the segfault when internally setting the replica identity for a given chunk.
* #7488: Emit error for transition table trigger on chunks.
* #7514: Fix the error: invalid child of chunk append.
* #7517: Fix the performance regression on the cagg_migrate procedure.
* #7527: Restart scheduler on error.
* #7557: Fix null handling for in-memory tuple filtering.
* #7566: Improve transaction check in CAGG refresh.
* #7584: Fix NaN-handling for vectorized aggregation.
Thanks
* @bharrisau for reporting the segfault when creating chunks.
* @k-rus for suggesting that we add a hint when hypertable creation fails.
* @pgloader for reporting the issue in an internal background job.
* @staticlibs for sending the pull request that improves the transaction check in CAGG refresh.
* @uasiddiqi for reporting the aggregated compressed column not found error.
timescale/timescaledb
