This release contains performance improvements and bug fixes since the 2.22.0 release. We recommend that you upgrade at the next available opportunity.

This release blocks the ability to create new concurrent refresh policies in hierarchical continuous aggregates, as in rare cases, a deadlock can occur. Concurrent refresh policies were introduced in 2.21.0 and allow users to define multiple time ranges, to refresh, e.g. data from the last hour in policy and the last day in a second policy. Existing concurrent refresh policies on hierarchical continuous aggregates will continue to be executed. To avoid any potential deadlock, remove such existing policies and create a new policy for the full range you want to refresh, of the continuous aggregate as follows:

--- Find the job ID's of the concurrent refresh policies
SELECT * FROM timescaledb_information.jobs WHERE proc_name = 'policy_refresh_continuous_aggregate';
--- Remove the job
SELECT delete_job("<job_id_of_concurrent_policy>");
--- Create new policy for hierarchical continuous aggregate
SELECT add_continuous_aggregate_policy('<name_of_materialized_view>',
  start_offset => INTERVAL '1 month',
  end_offset => INTERVAL '1 day',
  schedule_interval => INTERVAL '1 hour');

Bugfixes

• #7766 Load OSM extension in retention background worker to drop tiered chunks
• #8550 Error in gapfill with expressions over aggregates and groupby columns and out-of-order columns
• #8593 Error on change of invalidation method for continuous aggregate
• #8599 Fix attnum mismatch bug in chunk constraint checks
• #8607 Fix interrupted continous aggregate refresh materialization phase leaving behind pending materialization ranges
• #8638 ALTER TABLE RESET for orderby settings
• #8644 Fix migration script for sparse index configuration
• #8657 Fix CREATE TABLE WITH when using UUIDv7 partitioning
• #8659 Don't propagate ALTER TABLE commands to foreign data wrapper chunks
• #8693 Compressed index not chosen for varchar typed segmentby columns
• #8707 Block concurrent refresh policies for hierarchical continous aggregate due to potential deadlocks

Thanks

• @MKrkkl for reporting a bug in Gapfill queries with expressions over aggregates and groupby columns
• @brandonpurcell-dev for creating a test case that showed a bug in CREATE TABLE WITH when using UUIDv7 partitioning
• @snyrkill for reporting a bug when interrupting a continous aggregate refresh

This release contains performance improvements and bug fixes since the 2.21.3 release. We recommend that you upgrade at the next available opportunity.

Bugfixes

#8667 Fix wrong selectivity estimates uncovered by the recent Postgres minor releases 15.14, 16.10, 17.6.

This release contains performance improvements and bug fixes since the 2.21.3 release.

Highlighted features in TimescaleDB v2.22.0

• Sparse indexes on compressed hypertables can now be explicitly configured via ALTER TABLE rather than relying only on internal heuristics. Users can define indexes on multiple columns to improve query performance for their specific workloads.
• [Tech Preview] Continuous aggregates now support the timescaledb.invalidate_using option, enabling invalidations to be collected either via triggers on the hypertable or directly from WAL using logical decoding. Aggregates inherit the hypertable’s method if none is specified.
• UUIDv7 compression and vectorization are now supported. The compression algorithm leverages the timestamp portion for delta-delta compression while storing the random portion separately. The vectorized equality/inequality filters with bulk decompression deliver ~2× faster query performance. The feature is disabled by default (timescaledb.enable_uuid_compression) to simplify the downgrading experience, and will be enabled out of the box in the next minor release.
• Hypertables can now be partitioned by UUIDv7 columns, leveraging their embedded timestamps for time-based chunking. We’ve also added utility functions to simplify working with UUIDv7, such as generating values or extracting timestamps - e.g., uuid_timestamp() returns a PostgreSQL timestamp from a UUIDv7.
• SkipScan now supports multi-column indexes in not-null mode, improving performance for distinct and ordered queries across multiple keys.

Removal of the hypercore table access method
We made the decision to deprecate the hypercore table access method (TAM) with the 2.21.0 release. Hypercore TAM was an experiment and it did not show the performance improvements we hoped for. It is removed with this release. Upgrades to 2.22.0 and higher are blocked if TAM is still in use. Since TAM’s inception in 2.18.0, we learned that btrees were not the right architecture. Recent advancements in the columnstore, such as more performant backfilling, SkipScan, adding check constraints, and faster point queries, put the columnstore close to or on par with TAM without needing to store an additional index. We apologize for the inconvenience this action potentially causes and are here to assist you during the migration process.

Migration path

do $$
declare
   relid regclass;
begin
   for relid in
       select cl.oid from pg_class cl
       join pg_am am on (am.oid = cl.relam)
       where am.amname = 'hypercore'
   loop
       raise notice 'converting % to heap', relid::regclass;
       execute format('alter table %s set access method heap', relid);
   end loop;
end
$$;

Features

• #8247 Add configurable alter settings for sparse indexes
• #8306 Add option for invalidation collection using WAL for continuous aggregates
• #8340 Improve selectivity estimates for sparse minmax indexes, so that an index scan on a table in the columnstore is chosen more often when it's beneficial.
• #8360 Continuous aggregate multi-hypertable invalidation processing
• #8364 Remove hypercore table access method
• #8371 Show available timescaledb ALTER options when encountering unsupported options
• #8376 Change DecompressChunk custom node name to ColumnarScan
• #8385 UUID v7 functions for testing pre PG18
• #8393 Add specialized compression for UUIDs. Best suited for UUID v7, but still works with other UUID versions. This is experimental at the moment and backward compatibility is not guaranteed.
• #8398 Set default compression settings at compress time
• #8401 Support ALTER TABLE RESET for compression settings
• #8414 Vectorised filtering of UUID Eq and Ne filters, plus bulk decompression of UUIDs
• #8424 Block downgrade when orderby setting is NULL
• #8454 Remove internal unused index helper functions
• #8494 Improve job stat history retention policy
• #8496 Fix dropping chunks with foreign keys
• #8505 Add support for partitioning on UUIDv7
• #8513 Support multikey SkipScan when all keys are guaranteed to be non-null
• #8514 Concurrent continuous aggregates improvements
• #8528 Add the _timescaledb_functions.chunk_status_text helper function
• #8529 Optimize direct compress status handling

Bugfixes

• #8422 Don't require columnstore=false when using the TimescaleDB Apache 2 Edition
• #8493 Change log level of not null constraint message
• #8500 Fix uniqueness check with generated columns and hypercore
• #8545 Fix error in LOCF/Interpolate with out-of-order and repeated columns
• #8558 Error out on bad args when processing invalidation
• #8559 Fix timestamp out of range using end_offset=NULL on CAgg refresh policy

GUCs

• enable_multikey_skipscan: Enable SkipScan for multiple distinct keys, default: on
• enable_uuid_compression: Enable UUID compression functionality, default: off
• cagg_processing_wal_batch_size: Batch size when processing WAL entries, default: 10000
• cagg_processing_low_work_mem: Low working memory limit for continuous aggregate invalidation processing, default: 38.4MB
• cagg_processing_high_work_mem: High working memory limit for continuous aggregate invalidation processing, default: 51.2MB

Thanks

• @CodeTherapist for reporting an issue where foreign key checks did not work after several insert statements
• @moodgorning for reporting a bug in queries with LOCF/Interpolate using out-of-order columns
• @nofalx for reporting an error when using end_offset=NULL on CAgg refresh policy
• @pierreforstmann for fixing a bug that happened when dropping chunks with foreign keys
• @Zaczero for reporting a bug with CREATE TABLE WITH when using the TimescaleDB Apache 2 Edition

This release contains performance improvements and bug fixes since the 2.21.2 release. We recommend that you upgrade at the next available opportunity.

Bugfixes

• #8471 Fix MERGE behaviour with updated values

This release contains performance improvements and bug fixes since the 2.21.1 release. We recommend that you upgrade at the next available opportunity.

Bugfixes

• #8418 Fix duplicate constraints in JOIN queries
• #8426 Fix chunk skipping min/max calculation
• #8434 Allow show_chunks to process more than 65535 chunks

This release contains a bug fix since the 2.21.0 release. We recommend that you upgrade at the next available opportunity.

Bugfixes

• #8336 Fix generic plans for foreign key checks and prepared statements

Thanks

• @CodeTherapist for reporting the issue with foreign key checks not working after several INSERT statements

This release contains performance improvements and bug fixes since the 2.20.3 release. We recommend that you upgrade at the next available opportunity.

Highlighted features in TimescaleDB v2.21.0

• The attach & detach chunks feature allows manually adding or removing chunks from a hypertable with uncompressed chunks, similar to PostgreSQL’s partition management.
• Continued improvement of backfilling into the columnstore, achieving up to 2.5x speedup for constrained tables, by introducing caching logic that boosts throughput for writes to compressed chunks, bringing INSERT performance close to that of uncompressed chunks.
• Optimized DELETE operations on the columstore through batch-level deletions of non-segmentby keys in the filter condition, greatly improving performance to up to 42x faster in some cases, as well as reducing bloat, and lowering resource usage.
• The heavy lock taken in Continuous Aggregate refresh was relaxed, enabling concurrent refreshes for non-overlapping ranges and eliminating the need for complex customer workarounds.
• [tech preview] Direct Compress is an innovative TimescaleDB feature that improves high-volume data ingestion by compressing data in memory and writing it directly to disk, reducing I/O overhead, eliminating dependency on background compression jobs, and significantly boosting insert performance.

Sunsetting of the hypercore access method
We made the decision to deprecate hypercore access method (TAM) with the 2.21.0 release. It was an experiment, which did not show the signals we hoped for and will be sunsetted in TimescaleDB 2.22.0, scheduled for September 2025. Upgrading to 2.22.0 and higher will be blocked if TAM is still in use. Since TAM’s inception in 2.18.0, we learned that btrees were not the right architecture. The recent advancements in the columnstore—such as more performant backfilling, SkipScan, adding check constraints, and faster point queries—put the columnstore close to or on par with TAM without the storage from the additional index. We apologize for the inconvenience this action potentially causes and are here to assist you during the migration process.

Migration path

do $$
declare   
   relid regclass;
begin
   for relid in
       select cl.oid from pg_class cl
       join pg_am am on (am.oid = cl.relam)
       where am.amname = 'hypercore'
   loop
       raise notice 'converting % to heap', relid::regclass;
       execute format('alter table %s set access method heap', relid);
   end loop;
end
$$;

Features

• #8081 Use JSON error code for job configuration parsing
• #8100 Support splitting compressed chunks
• #8131 Add policy to process hypertable invalidations
• #8141 Add function to process hypertable invalidations
• #8165 Reindex recompressed chunks in compression policy
• #8178 Add columnstore option to CREATE TABLE WITH
• #8179 Implement direct DELETE on non-segmentby columns
• #8182 Cache information for repeated upserts into the same compressed chunk
• #8187 Allow concurrent Continuous Aggregate refreshes
• #8191 Add option to not process hypertable invalidations
• #8196 Show deprecation warning for TAM
• #8208 Use NULL compression for bool batches with all null values like the other compression algorithms
• #8223 Support for attach/detach chunk
• #8265 Set incremental Continous Aggregate refresh policy on by default
• #8274 Allow creating concurrent continuous aggregate refresh policies
• #8314 Add support for timescaledb_lake in loader
• #8209 Add experimental support for Direct Compress of COPY
• #8341 Allow quick migration from hypercore TAM to (columnstore) heap

Bugfixes

• #8153 Restoring a database having NULL compressed data
• #8164 Check columns when creating new chunk from table
• #8294 The "vectorized predicate called for a null value" error for WHERE conditions like x = any(null::int[]).
• #8307 Fix missing catalog entries for bool and null compression in fresh installations
• #8323 Fix DML issue with expression indexes and BHS

GUCs

• enable_direct_compress_copy: Enable experimental support for direct compression during COPY, default: off
• enable_direct_compress_copy_sort_batches: Enable batch sorting during direct compress COPY, default: on
• enable_direct_compress_copy_client_sorted: Correct handling of data sorting by the user is required for this option, default: off

This release contains bug fixes since the 2.20.2 release. We recommend that you upgrade at the next available opportunity.

Bugfixes

• #8107 Adjust SkipScan cost for quals needing full scan of indexed data.
• #8211 Fixed dump and restore when chunk skipping is enabled.
• #8216 Fix for dropped quals bug in SkipScan.
• #8230 Fix for inserting into compressed data when vectorised check is not available.
• #8236 Fixed the snapshot handling in background workers.

Thanks

• @ikaakkola for reporting that SkipScan is slow when non-index quals do not match any tuples.

This release contains bug fixes since the 2.20.1 release. We recommend that you upgrade at the next available opportunity.

Bugfixes

• #8202 Fix NULL compression handling for vectorized constraint checking

This release contains performance improvements and bug fixes since the 2.20.0 release. We recommend that you upgrade at the next available opportunity.

Features

• #8145 Log only if compression ratio warnings are enabled

Bugfixes

• #7292 Intermittent "could not find pathkey item to sort" error when grouping or ordering by a time_bucket of an equality join variable.
• #8126 Allow setting bgw_log_level to FATAL and ERROR
• #8151 Treat null equal to null for merged Continous Aggregate refresh
• #8153 Restoring a database having NULL compressed data
• #8162 Fix setting compress_chunk_interval on continuous aggregates
• #8163 Fix gapfill crash with locf NULL values treated as missing
• #8171 Disable decompression limit during continuous aggregate refresh

Thanks

• @bobozaur, @kvc0, @ChadMoran, @PaddyKe for reporting the pathkey error.
• @jlordiales for reporting an issue with setting compress_chunk_interval for continuous aggregates
• @svanharmelen, @cmdjulian, @etaMS20 for reporting time_bucket_gapfill with locf crash when NULL values are treated as missing