On 8/24/23 11:19 AM, Alvaro Herrera wrote:
On 2023-Aug-24, Jonathan S. Katz wrote:### Performance Improvements PostgreSQL 16 improves the performance of existing PostgreSQL functionality through new query planner optimizations. In this latest release, the query planner can parallelize `FULL` and `RIGHT` joins, generate better optimized plans for queries that use aggregate functions (e.g. `count`) with a `DISTINCT` or `ORDER BY` clause, utilize incremental sorts for `SELECT DISTINCT` queries, and optimize window function executions so they execute more efficiently."optimize window function executions so that they execute blah" sounds redundant and strange. Maybe just "optimize execution of window functions" is sufficient? Also, using "e.g." there looks somewhat out of place; maybe "(such as `count`)" is a good replacement?It also introduces `RIGHT` and `OUTER` "anti-joins", which enable users to identify rows not present in a joined table.Wait. Are you saying we didn't have those already? Looking at release-16.sgml I think this refers to commit 16dc2703c541, which means this made them more efficient rather than invented them.This release includes improvements for bulk loading using `COPY` in both single and concurrent operations, with tests showing up to a 300% performance improvement in some cases. PostgreSQL adds support for load balancing in clientsPostgreSQL 16that use `libpq`, and improvements to vacuum strategy that reduce the necessity of full-table freezes. Additionally, PostgreSQL 16 introduces CPU acceleration using `SIMD` in both x86 and ARM architectures, resulting in performance gains when processing ASCII and JSON strings, and performing array and subtransaction searches. ### Logical replication Logical replication lets PostgreSQL users stream data to other PostgreSQL"L.R. in PostgreSQL lets users"?instances or subscribers that can interpret the PostgreSQL logical replication protocol. In PostgreSQL 16, users can perform logical decoding from a standbys/decoding/replication/ ? (It seems odd to use "decoding" when the previous sentence used "replication")instance, meaning a standby can publish logical changes to other servers. This provides developers with new workload distribution options – for example, using a standby rather than the busier primary to logically replicate changes to downstream systems. Additionally, there are several performance improvements in PostgreSQL 16 to logical replication. Subscribers can now apply large transactions using parallel workers. For tables that do not have a `PRIMARY KEY`, subscribers can use B-tree"a primary key", no caps.indexes instead of sequential scans to find rows. Under certain conditions, users can also speed up initial table synchronization using the binary format. There are several access control improvements to logical replication in PostgreSQL 16, including the new predefined role pg_create_subscription, which grants users the ability to create a new logical subscription. Finally, this release begins adding support for bidirectional logical replication, introducing functionality to replicate data between two tables from different publishers."to create a new logical subscription" -> "to create new logical subscriptions"### Developer Experience PostgreSQL 16 adds more syntax from the SQL/JSON standard, including constructors and predicates such as `JSON_ARRAY()`, `JSON_ARRAYAGG()`, and `IS JSON`. This release also introduces the ability to use underscores for thousands separators (e.g. `5_432_000`) and non-decimal integer literals, such as `0x1538`, `0o12470`, and `0b1010100111000`. Developers using PostgreSQL 16 will also benefit from the addition of multiple commands to `psql` client protocol, including the `\bind` command, which allows users to execute parameterized queries (e.g `SELECT $1 + $2`) then use `\bind` to substitute the variables.This paragraph sounds a bit suspicious. What do you mean with "multiple commands to psql client protocol"? Also, I think "to execute parameterized queries" should be "to prepare parameterized queries", and later "then use \bind to execute the query substituting the variables".### Monitoring A key aspect of tuning the performance of database workloads is understanding the impact of your I/O operations on your system. PostgreSQL 16 helps simplify how you can analyze this data with the new pg_stat_io view, which tracks key I/O statistics such as shared_buffer hits and I/O latency.Hmm, I think what pg_stat_io gives you is data which wasn't available previously at all. Maybe do something like "Pg 16 introduces pg_stat_io, a new source of key I/O metrics that can be used for more fine grained something something".Additionally, this release adds a new field to the `pg_stat_all_tables` view that records a timestamp representing when a table or index was last scanned. PostgreSQL also makes auto_explain more readable by logging values passed intoPostgreSQL 16parameterized statements, and improves accuracy of pg_stat_activity's normalization algorithm.I think jian already mentioned that this refers to pg_stat_statement query fingerprinting. I know that the query_id also appears in pg_stat_activity, but that is much newer, and it's not permanent there like in pss. Maybe it should be "of the query fingerprinting algorithm used by pg_stat_statement and pg_stat_activity".## Images and Logos Postgres, PostgreSQL, and the Elephant Logo (Slonik) are all registered trademarks of the [PostgreSQL Community Association of Canada](https://www.postgres.ca).Isn't this just the "PostgreSQL Community Association", no Canada?
Thanks for the feedback. I accepted most of the changes. Please see revised text here, which also includes the URL substitutions.
Jonathan
September 14, 2023 - The PostgreSQL Global Development Group today announced the release of PostgreSQL 16, the latest version of the world's most advanced open source database. [PostgreSQL 16](https://www.postgresql.org/docs/16/release-16.html) raises its performance, with notable improvements to query parallelism, bulk data loading, and logical replication. There are many features in this release for developers and administrators alike, including more SQL/JSON syntax, new monitoring stats for your workloads, and greater flexibility in defining access control rules for management of policies across large fleets. <HOLD FOR QUOTE> PostgreSQL, an innovative data management system known for its reliability and robustness, benefits from over 25 years of open source development from a global developer community and has become the preferred open source relational database for organizations of all sizes. ### Performance Improvements PostgreSQL 16 improves the performance of existing PostgreSQL functionality through new query planner optimizations. In this latest release, the [query planner can parallelize](https://www.postgresql.org/docs/16/parallel-query.html) `FULL` and `RIGHT` [joins](https://www.postgresql.org/docs/16/queries-table-expressions.html#QUERIES-JOIN), generate better optimized plans for queries that use [aggregate functions](https://www.postgresql.org/docs/16/functions-aggregate.html) with a `DISTINCT` or `ORDER BY` clause, utilize incremental sorts for [`SELECT DISTINCT`](https://www.postgresql.org/docs/16/queries-select-lists.html#QUERIES-DISTINCT) queries, and optimize [window functions](https://www.postgresql.org/docs/16/sql-expressions.html#SYNTAX-WINDOW-FUNCTIONS) so they execute more efficiently. It also improves `RIGHT` and `OUTER` "anti-joins", which enables users to identify rows not present in a joined table. This release includes improvements for bulk loading using [`COPY`](https://www.postgresql.org/docs/16/sql-copy.html) in both single and concurrent operations, with tests showing up to a 300% performance improvement in some cases. PostgreSQL 16 adds support for [load balancing](https://www.postgresql.org/docs/16/libpq-connect.html#LIBPQ-CONNECT-LOAD-BALANCE-HOSTS) in clients that use `libpq`, and improvements to vacuum strategy that reduce the necessity of full-table freezes. Additionally, PostgreSQL 16 introduces CPU acceleration using `SIMD` in both x86 and ARM architectures, resulting in performance gains when processing ASCII and JSON strings, and performing array and subtransaction searches. ### Logical replication [Logical replication](https://www.postgresql.org/docs/16/logical-replication.html) lets users stream data to other PostgreSQL instances or subscribers that can interpret the PostgreSQL logical replication protocol. In PostgreSQL 16, users can perform logical replication from a standby instance, meaning a standby can publish logical changes to other servers. This provides developers with new workload distribution options – for example, using a standby rather than the busier primary to logically replicate changes to downstream systems. Additionally, there are several performance improvements in PostgreSQL 16 to logical replication. Subscribers can now apply large transactions using parallel workers. For tables that do not have a [primary key](https://www.postgresql.org/docs/16/ddl-constraints.html#DDL-CONSTRAINTS-PRIMARY-KEYS), subscribers can use B-tree indexes instead of sequential scans to find rows. Under certain conditions, users can also speed up initial table synchronization using the binary format. There are several access control improvements to logical replication in PostgreSQL 16, including the new [predefined role](https://www.postgresql.org/docs/16/predefined-roles.html) `pg_create_subscription`, which grants users the ability to create anew logical subscriptions. Finally, this release begins adding support for bidirectional logical replication, introducing functionality to replicate data between two tables from different publishers. ### Developer Experience PostgreSQL 16 adds more syntax from the [SQL/JSON](https://www.postgresql.org/docs/16/functions-json.html) standard, including constructors and predicates such as `JSON_ARRAY()`, `JSON_ARRAYAGG()`, and `IS JSON`. This release also introduces the ability to use underscores for thousands separators (e.g. `5_432_000`) and non-decimal integer literals, such as `0x1538`, `0o12470`, and `0b1010100111000`. Developers using PostgreSQL 16 also benefit from new commands in `psql`. This includes [`\bind`](https://www.postgresql.org/docs/16/app-psql.html#APP-PSQL-META-COMMAND-BIND), which allows users to prepare parameterized queries and use `\bind` to substitute the variables (e.g `SELECT $1::int + $2::int \bind 1 2 \g `). PostgreSQL 16 improves general support for [text collations](https://www.postgresql.org/docs/16/collation.html), which provide rules for how text is sorted. PostgreSQL 16 builds with ICU support by default, determines the default ICU locale from the environment, and allows users to define custom ICU collation rules. ### Monitoring A key aspect of tuning the performance of database workloads is understanding the impact of your I/O operations on your system. PostgreSQL 16 introduces [`pg_stat_io`](https://www.postgresql.org/docs/16/monitoring-stats.html#MONITORING-PG-STAT-IO-VIEW), a new source of key I/O metrics for granular analysis of I/O access patterns. Additionally, this release adds a new field to the [`pg_stat_all_tables`](https://www.postgresql.org/docs/16/monitoring-stats.html#MONITORING-PG-STAT-ALL-TABLES-VIEW) view that records a timestamp representing when a table or index was last scanned. PostgreSQL 16 also makes [`auto_explain`](https://www.postgresql.org/docs/16/auto-explain.html) more readable by logging values passed into parameterized statements, and improves the accuracy of the query tracking algorithm used by [`pg_stat_statements`](https://www.postgresql.org/docs/16/pgstatstatements.html) and [`pg_stat_activity`](https://www.postgresql.org/docs/16/monitoring-stats.html#MONITORING-PG-STAT-ACTIVITY-VIEW). ### Access Control & Security PostgreSQL 16 provides finer-grained options for access control and enhances other security features. The release improves management of [`pg_hba.conf`](https://www.postgresql.org/docs/16/auth-pg-hba-conf.html) and [`pg_ident.conf`](https://www.postgresql.org/docs/16/auth-username-maps.html) files, including allowing regular expression matching for user and database names and `include` directives for external configuration files. This release adds several security-oriented client connection parameters, including require_auth, which allows clients to specify which authentication parameters they are willing to accept from a server, and [`sslrootcert="system"`](https://www.postgresql.org/docs/16/libpq-connect.html#LIBPQ-CONNECT-SSLROOTCERT), which indicates that PostgreSQL should use the trusted certificate authority (CA) store provided by the client's operating system. Additionally, the release adds support for Kerberos credential delegation, allowing extensions such as [`postgres_fdw`](https://www.postgresql.org/docs/16/postgres-fdw.html) and [`dblink`](https://www.postgresql.org/docs/16/dblink.html) to use authenticated credentials to connect to trusted services. ### About PostgreSQL [PostgreSQL](https://www.postgresql.org) is the world's most advanced open source database, with a global community of thousands of users, contributors, companies and organizations. Built on over 35 years of engineering, starting at the University of California, Berkeley, PostgreSQL has continued with an unmatched pace of development. PostgreSQL's mature feature set not only matches top proprietary database systems, but exceeds them in advanced database features, extensibility, security, and stability. ### Links * [Download](https://www.postgresql.org/download/) * [Release Notes](https://www.postgresql.org/docs/16/release-16.html) * [Press Kit](https://www.postgresql.org/about/press/) * [Security Page](https://www.postgresql.org/support/security/) * [Versioning Policy](https://www.postgresql.org/support/versioning/) * [Follow @postgresql](https://twitter.com/postgresql) * [Donate](https://www.postgresql.org/about/donate/) ## More About the Features For explanations of the above features and others, please see the following resources: * [Release Notes](https://www.postgresql.org/docs/16/release-16.html) * [Feature Matrix](https://www.postgresql.org/about/featurematrix/) ## Where to Download There are several ways you can download PostgreSQL 16, including: * The [Official Downloads](https://www.postgresql.org/download/) page, with contains installers and tools for [Windows](https://www.postgresql.org/download/windows/), [Linux](https://www.postgresql.org/download/linux/), [macOS](https://www.postgresql.org/download/macosx/), and more. * [Source Code](https://www.postgresql.org/ftp/source/v16.0) Other tools and extensions are available on the [PostgreSQL Extension Network](http://pgxn.org/). ## Documentation PostgreSQL 16 comes with HTML documentation as well as man pages, and you can also browse the documentation online in both [HTML](https://www.postgresql.org/docs/16/) and [PDF](https://www.postgresql.org/files/documentation/pdf/16/postgresql-16-US.pdf) formats. ## Licence PostgreSQL uses the [PostgreSQL License](https://www.postgresql.org/about/licence/), a BSD-like "permissive" license. This [OSI-certified license](http://www.opensource.org/licenses/postgresql/) is widely appreciated as flexible and business-friendly, since it does not restrict the use of PostgreSQL with commercial and proprietary applications. Together with multi-company support and public ownership of the code, our license makes PostgreSQL very popular with vendors wanting to embed a database in their own products without fear of fees, vendor lock-in, or changes in licensing terms. ## Contacts Website * [https://www.postgresql.org/](https://www.postgresql.org/) Email * [pr...@postgresql.org](mailto:pr...@postgresql.org) ## Images and Logos Postgres, PostgreSQL, and the Elephant Logo (Slonik) are all registered trademarks of the [PostgreSQL Community Association](https://www.postgres.ca). If you wish to use these marks, you must comply with the [trademark policy](https://www.postgresql.org/about/policies/trademarks/). ## Corporate Support PostgreSQL enjoys the support of numerous companies, who sponsor developers, provide hosting resources, and give us financial support. See our [sponsors](https://www.postgresql.org/about/sponsors/) page for some of these project supporters. There is also a large community of [companies offering PostgreSQL Support](https://www.postgresql.org/support/professional_support/), from individual consultants to multinational companies. If you wish to make a financial contribution to the PostgreSQL Global Development Group or one of the recognized community non-profit organizations, please visit our [donations](https://www.postgresql.org/about/donate/) page.
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