Release 2.16.0

[pallavisontakke]

This release contains significant performance improvements when working with compressed data, extended join
support in continuous aggregates, and the ability to define foreign keys from regular tables towards hypertables.
We recommend that you upgrade at the next available opportunity.

In TimescaleDB v2.16.0 we:

• Introduce multiple performance focused optimizations for data manipulation operations (DML) over compressed chunks.

  Improved upsert performance by more than 100x in some cases and more than 1000x in some update/delete scenarios.

• Add the ability to define sparse indexes on non-partitioning columns of compressed hypertables

  TimescaleDB v2.16.0 extends chunk exclusion to use those sparse indexes when queries filter on the relevant columns,
  and prune chunks that do not include any relevant data for calculating the query response.

• Offer new options for use cases that require foreign keys defined.

  You can now add foreign keys from regular tables towards hypertables. We have also removed
  some really annoying locks in the reverse direction that blocked access to referenced tables
  while compression was running.

• Extend Continuous Aggregates to support more types of analytical queries.

  More types of joins are supported, additional equality operators on join clauses, and
  support for joins between multiple regular tables.

Highlighted features in this release

• Improved query performance through chunk exclusion on compressed hypertables.

  You can now define sparse indexes on compressed chunks for any column with one of the following
  integer data types: smallint, int, bigint, serial, bigserial, date, timestamp, timestamptz.

  After you call enable_column_stats on a column, TimescaleDB tracks the min and max values for
  that column. TimescaleDB uses that information to exclude chunks for queries that filter on that
  column, and would not find any data in those chunks.

• Improved upsert performance on compressed hypertables.

  By using index scans to verify constraints during inserts on compressed chunks, TimescaleDB speeds
  up some ON CONFLICT clauses by more than 100x.

• Improved performance of updates, deletes, and inserts on compressed hypertables.

  By filtering data while accessing the compressed data and before decompressing, TimescaleDB has
  improved performance for updates and deletes on all types of compressed chunks, as well as inserts
  into compressed chunks with unique constraints.

  By signaling constraint violations without decompressing, or decompressing only when matching
  records are found in the case of updates, deletes and upserts, TimescaleDB v2.16.0 speeds
  up those operations more than 1000x in some update/delete scenarios, and 10x for upserts.

• You can add foreign keys from regular tables to hypertables, with support for all types of cascading options.
  This is useful for hypertables that partition using sequential IDs, and need to reference those IDs from other tables.

• Lower locking requirements during compression for hypertables with foreign keys

  Advanced foreign key handling removes the need for locking referenced tables when new chunks are compressed.
  DML is no longer blocked on referenced tables while compression runs on a hypertable.

• Improved support for queries on Continuous Aggregates

  INNER/LEFT and LATERAL joins are now supported. Plus, you can now join with multiple regular tables,
  and you can have more than one equality operator on join clauses.

PostgreSQL 13 support removal announcement

Following the deprecation announcement for PostgreSQL 13 in TimescaleDB v2.13,
PostgreSQL 13 is no longer supported in TimescaleDB v2.16.

The Currently supported PostgreSQL major versions are 14, 15 and 16.

Features

• Add support for array operations to compressed DML #6880: Add support for the array operators used for compressed DML batch filtering.
• Improve compressed DML expression pushdown #6895: Improve the compressed DML expression pushdown.
• Allow replica identity on compressed hypertables #6897: Add support for replica identity on compressed hypertables.
• Remove PG13 support #6918: Remove support for PG13.
• Rework compression activity wal markers #6920: Rework compression activity wal markers.
• Add support for foreign keys to hypertables #6989: Add support for foreign keys when converting plain tables to hypertables.
• Add support for chunk column statistics tracking #7020: Add support for the chunk column statistics tracking.
• Add index scan to INSERT DML decompression #7048: Add an index scan for INSERT DML decompression.
• Reduce decompression on compressed INSERT #7075: Reduce decompression on the compressed INSERT.
• Reduce decompressions for compressed UPDATE/DELETE #7101: Reduce decompressions for the compressed UPDATE/DELETE.
• Reduce decompression for INSERT with unique constraints #7108: Reduce decompressions for the INSERTs with UNIQUE constraints.
• Use DELETE after compression #7116: Use DELETE instead of TRUNCATE after compression.
• Change hypertable foreign key handling #7134: Refactor foreign key handling for compressed hypertables.

Bugfixes

• Fix search_path quoting in compression defaults function #7018: Fix search_path quoting in the compression defaults function.
• Prevent locking compressed tuples #7046: Prevent locking for compressed tuples.
• Fix scankey where consttype is different from var #7055: Fix the scankey for segment by columns, where the type constant is different to variable.
• Fix a bug in default orderby calc. in compression #7064: Fix the bug in the default order by calculation in compression.
• Don't use index column names #7069: Fix the index column name usage.
• Fix bug in default segmentby calc. in compression #7074: Fix the bug in the default segment by calculation in compression.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

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Additional details and impacted files

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  Coverage          ?   81.77%           
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  Files             ?      203           
  Lines             ?    37975           
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  Hits              ?    31053           
  Misses            ?     2970           
  Partials          ?     3952           

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[iroussos]

Thank you @pallavisontakke - added some final small changes on the changelog based on feedback by Ramon.

Approving on my end - no further comments other than this change

[iroussos]

Adding a review comment requesting changes to block from accidentally merging - we need to do one last change before we can move forward with 2.16

Internal discussion for more information:
https://iobeam.slack.com/archives/C060QFPDQPM/p1721932110641679