Release 12:
General performance improvements, including:
* Optimizations to space utilization and read/write performance for B-tree indexes
* Partitioning performance enhancements, including improved query performance on tables with thousands of partitions, improved insertion performance with INSERT and COPY, and the ability to execute ALTER TABLE ATTACH PARTITION without blocking queries
* Automatic (but overridable) inlining of common table expressions (CTEs)
* Reduction of WAL overhead for creation of GiST, GIN, and SP-GiST indexes
* Support for covering GiST indexes, via the INCLUDE clause
* Multi-column most-common-value (MCV) statistics can be defined via CREATE STATISTICS, to support better plans for queries that test several non-uniformly-distributed columns
Enhancements to administrative functionality, including:
* REINDEX CONCURRENTLY can rebuild an index without blocking writes to its table
* pg_checksums can enable/disable page checksums (used for detecting data corruption) in an offline cluster
* Progress reporting statistics for CREATE INDEX, REINDEX, CLUSTER, VACUUM FULL, and pg_checksums
Support for the SQL/JSON path language
Stored generated columns
Nondeterministic ICU collations, enabling case-insensitive and accent-insensitive grouping and ordering
New authentication features, including:
* Encryption of TCP/IP connections when using GSSAPI authentication
* Discovery of LDAP servers using DNS SRV records
* Multi-factor authentication, using the clientcert=verify-full option combined with an additional authentication method in pg_hba.conf
