PostgreSQL是一個功能強大的開源關聯式資料庫管理系統，被廣泛用於現代軟體開發中。由一個專業的志願者團隊開發，PostgreSQL 提供了一套強大的功能和性能，使其成為各種規模企業和組織的熱門選擇。

PostgreSQL 的一個關鍵優勢是它能夠輕鬆處理大型和複雜的數據集。它可以以多種格式存儲和管理數據，包括文本、圖片、音頻和視頻。此外，PostgreSQL 支援先進的數據類型，如陣列、hstore 和 JSON，允許開發者以更靈活和直觀的方式處理結構化和非結構化數據。

由於支持用戶定義的函數、儲存過程和觸發器，PostgreSQL 也高度可定制和可擴展。這使得它成為構建需要自定義邏輯和處理的複雜應用程式的理想選擇。

PostgreSQL 的另一個重要特點是其強大的安全模型。它提供了一系列安全選項，包括加密、SSL 連接和基於角色的訪問控制，這使開發人員能夠確保他們的數據免受未經授權的訪問。

除了其技術能力之外，PostgreSQL 還受益於一個充滿活力且活躍的開發者和用戶社群。這個社群為 PostgreSQL 用戶提供了豐富的資源和支持，包括文檔、論壇和用戶群組。

PostgreSQL 是一個可靠、強大且靈活的數據庫管理系統，非常適合各種應用和使用案例。無論您是在構建小型網絡應用還是大型企業系統，PostgreSQL 都提供您成功所需的可擴展性、靈活性和安全性。

主要特點：

• 可靠的交易（ACID 合規性）
• 易於擴展用戶自定義函數和數據類型
• 有效處理多個並發交易
• 可透過分區和分片進行擴展
• 用於快速數據檢索的高級索引選項
• 全文檢索功能
• 支持結構化和半結構化數據（JSON 和 JSONB 數據類型）
• 透過 FDWs 無縫整合外部資料來源
• 內建複製功能，便於設定複製
• 強而有力的安全機制來保護敏感數據。

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