PostgreSQL是一个功能强大的开源关系数据库管理系统，在现代软件开发中广泛使用。由一群敬业的志愿者开发，PostgreSQL 提供了强大的功能和性能，使其成为各种规模企业和组织的热门选择。

PostgreSQL的主要优势之一是其轻松处理大型和复杂数据集的能力。它可以以多种格式存储和管理数据，包括文本、图像、音频和视频。此外，PostgreSQL支持高级数据类型，如数组、hstore和JSON，这使得开发人员可以更灵活和直观地处理结构化和非结构化数据。

PostgreSQL 也高度可定制和可扩展，这要归功于其对用户定义函数、存储过程和触发器的支持。这使其成为构建需要自定义逻辑和处理的复杂应用程序的理想选择。

PostgreSQL的另一个重要特性是其强大的安全模型。它提供一系列安全选项，包括加密、SSL连接和基于角色的访问控制，这些选项使开发人员能够确保他们的数据免受未经授权的访问。

除了其技术能力外，PostgreSQL 还受益于一个充满活力且活跃的开发人员和用户社区。这个社区为 PostgreSQL 用户提供丰富的资源和支持，包括文档、论坛和用户组。

PostgreSQL是一个可靠、强大且灵活的数据库管理系统，适合广泛的应用和使用案例。无论您是在构建小型网络应用程序还是大型企业系统，PostgreSQL都能提供所需的可扩展性、灵活性和安全性以取得成功。

主要功能：

• 可靠交易（ACID合规性）
• 易于使用用户自定义函数和数据类型进行扩展
• 高效处理多个并发事务
• 通过分区和分片实现可扩展性
• 用于快速数据检索的高级索引选项
• 全文搜索功能
• 支持结构化和半结构化数据（JSON和JSONB数据类型）
• 通过FDW与外部数据源进行无缝集成
• 内置复制功能，便于复制设置
• 强大的安全机制用于保护敏感数据。

Version 9.3.3

Shore up GRANT ... WITH ADMIN OPTION restrictions

Granting a role without ADMIN OPTION is supposed to prevent the grantee from adding or removing members from the granted role, but this restriction was easily bypassed by doing SET ROLE first. The security impact is mostly that a role member can revoke the access of others, contrary to the wishes of his grantor. Unapproved role member additions are a lesser concern, since an uncooperative role member could provide most of his rights to others anyway by creating views or SECURITY DEFINER functions.

Prevent privilege escalation via manual calls to PL validator functions

The primary role of PL validator functions is to be called implicitly during CREATE FUNCTION, but they are also normal SQL functions that a user can call explicitly. Calling a validator on a function actually written in some other language was not checked for and could be exploited for privilege-escalation purposes. The fix involves adding a call to a privilege-checking function in each validator function. Non-core procedural languages will also need to make this change to their own validator functions, if any.

Avoid multiple name lookups during table and index DDL

If the name lookups come to different conclusions due to concurrent activity, we might perform some parts of the DDL on a different table than other parts. At least in the case of CREATE INDEX, this can be used to cause the permissions checks to be performed against a different table than the index creation, allowing for a privilege escalation attack.
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See more details here: http://www.postgresql.org/docs/current/static/release-9-3-3.html