An identity column is a special column that is generated automatically from an implicit sequence. It can be used to generate key values. Similarly, the keyword DEFAULT can be used in UPDATE commands.

A transaction reads data written by a concurrent uncommitted transaction. nonrepeatable read A transaction re-reads data it has previously read and finds that data has been modified by another ...

PostgreSQL全球开发组今天宣布，世界上功能最为强大的开源数据库发布PostgreSQL 12版本发布。 PostgreSQL 12版在各方面都得到了加强，包括显著地提升查询性能，特别是对大数据集，总的空间利用率方面。 这个版本为应用程序开发人员提供了更多的功能，比如对SQL/JSON ...

The following parameters are intended for developer testing, and should never be used on a production database. However, some of them can be used to assist with the recovery of severely damaged ...

If you have pattern matching needs that go beyond this, consider writing a user-defined function in Perl or Tcl. While most regular-expression searches can be executed very quickly, regular ...

JSON data types are for storing JSON (JavaScript Object Notation) data, as specified in RFC 7159. Such data can also be stored as text, but the JSON data types have the advantage of enforcing that ...

Sets the amount of memory the database server uses for shared memory buffers. The default is typically 128 megabytes (128MB), but might be less if your kernel settings will not support it (as ...

PostgreSQL supports basic table partitioning. This section describes why and how to implement partitioning as part of your database design. These benefits will normally be worthwhile only when a table ...

Any SQL command can be run from within an embedded SQL application. Below are some examples of how to do that. To retrieve a result set holding multiple rows, an application has to declare a cursor ...

SASL is a framework for authentication in connection-oriented protocols. At the moment, PostgreSQL implements two SASL authentication mechanisms, SCRAM-SHA-256 and SCRAM-SHA-256-PLUS. More might be ...

The PoWA team is pleased to announce the release of the version 2.3.0 ofpg_stat_kcache, an extension that gathers statistics about real reads and writes done by the ...

This release contains a variety of fixes from 14.10. For information about new features in major release 14, see Section E.14. A dump/restore is not required for those running 14.X. However, one bug ...