PostgreSQL 9.0.2

PostgreSQL 是一款功能強大、開放原始碼的物件關聯式資料庫系統。它歷經超過 15 年的積極開發，其成熟的架構為可靠性、資料完整性與正確性贏得了良好聲譽。

它可在所有主流作業系統上執行，包括 Linux、UNIX（AIX、BSD、HP-UX、SGI IRIX、macOS、Solaris、Tru64）以及 Windows。PostgreSQL 是一款強大的物件關聯式資料庫管理系統！下載適用於 PC 的 PostgreSQL 離線安裝程式 64 位元版本！

它完全符合 ACID 規範，並完整支援外部鍵、聯結、檢視、觸發器以及預存程序（支援多種語言）。它包含大多數 SQL:2008 資料型別，包括 INTEGER、NUMERIC、BOOLEAN、CHAR、VARCHAR、DATE、INTERVAL 和 TIMESTAMP。

它也支援儲存二進位大型物件，包括圖片、音訊或影片。它具備 C/C++、Java、.Net、Perl、Python、Ruby、Tcl、ODBC 等原生程式設計介面，並提供卓越的文件（資料表大小最高可達 32 TB）。

PostgreSQL 2026 具備許多功能，旨在協助開發人員建置應用程式、協助管理員保護資料完整性並建置容錯環境，同時協助您管理任何規模的資料集。除了免費且開放原始碼之外，這款工具還具有高度擴充性。

例如，您可以定義自己的資料型別、建立自訂函式，甚至使用不同的程式語言撰寫程式碼，而無需重新編譯資料庫！

此應用程式力求在符合 SQL 標準的同時，不與傳統功能牴觸，也不會導致不良的架構決策。

SQL 標準要求的許多功能都已支援，不過有時語法或功能會略有差異。未來可望進一步提升標準符合度。

功能與重點

資料型別

• 基本型別：整數、數值、字串、布林值
• 結構化：日期/時間、陣列、範圍、UUID
• 文件型別：JSON/JSONB、XML、鍵值對（Hstore）
• 幾何型別：點、線、圓、多邊形
• 自訂：複合型別、自訂型別

資料完整性

• UNIQUE、NOT NULL
• 主鍵
• 外部鍵
• 排除約束
• 明確鎖定、建議鎖定

並行性與效能

• 索引：B-tree、多欄位、運算式、部分索引
• 進階索引：GiST、SP-GiST、KNN GiST、GIN、BRIN、涵蓋索引、布隆過濾器
• 精密的查詢規劃器/最佳化器、僅索引掃描、多欄位統計
• 交易、巢狀交易（透過儲存點）
• 多版本並行控制（MVCC）
• 讀取查詢與建立 B-tree 索引的平行化
• 資料表分割
• SQL 標準定義的所有交易隔離層級，包括可序列化
• 運算式的即時（JIT）編譯

可靠性與災難復原

• 預寫式記錄（WAL）
• 複寫：非同步、同步、邏輯
• 時間點復原（PITR）、主動備援
• 資料表空間

安全性

• 驗證：GSSAPI、SSPI、LDAP、SCRAM-SHA-256、憑證等
• 健全的存取控制系統
• 欄位與列層級安全性

擴充性

• 預存函式與程序
• 程序語言：PL/pgSQL、Perl、Python（以及更多）
• 外部資料包裝器：透過標準 SQL 介面連線至其他資料庫或串流
• 許多提供額外功能的擴充套件，包括 PostGIS

國際化與全文檢索

• 支援國際字元集，例如透過 ICU 定序
• 全文檢索

使用方式

• 從官方網站或 FileHorse.com 下載並安裝此程式
• 開啟 pgAdmin 或使用命令列進行資料庫管理
• 使用 pgAdmin 介面建立新資料庫
• 使用 SQL 查詢來建立、讀取、更新和刪除資料
• 設定使用者角色與權限以確保安全性
• 使用 pgAdmin 或命令列備份與還原資料庫
• 使用索引與查詢調校來最佳化效能
• 使用 PostgreSQL 相容驅動程式連線應用程式
• 使用內建記錄工具監控資料庫活動
• 保持 PostgreSQL 更新以確保安全性與效能

系統需求

作業系統：Windows 11 或 Windows 10（64 位元）

處理器：Intel 或 AMD 64 位元處理器

記憶體：最低 2GB，建議 4GB 或以上

儲存空間：安裝至少需要 100MB，資料儲存另需更多空間

其他需求：需要 Microsoft Visual C++ 可轉散發套件

優點

• 開放原始碼且免費使用
• 進階安全性功能
• 高擴充性與效能
• 支援複雜查詢與索引
• 強大的社群與文件

缺點

• 需要手動效能調校
• 某些情況下記憶體使用量較高
• 內建 GUI 管理工具有限
• 升級可能需要手動調整

另有提供：下載 PostgreSQL for Mac

下載 PostgreSQL 最新版本 為什麼此應用程式發佈在 FileHorse 上？（更多資訊）

# Changes

* Force the default wal_sync_method to be fdatasync on Linux The default on Linux has actually been fdatasync for many years, but recent kernel changes caused PostgreSQL to choose open_datasync instead. This choice did not result in any performance improvement, and caused outright failures on certain filesystems, notably ext4 with the data=journal mount option.
* Fix "too many KnownAssignedXids" error during Hot Standby replay
* Fix race condition in lock acquisition during Hot Standby
* Avoid unnecessary conflicts during Hot Standby This fixes some cases where replay was considered to conflict with standby queries (causing delay of replay or possibly cancellation of the queries), but there was no real conflict.
* Fix assorted bugs in WAL replay logic for GIN indexes This could result in "bad buffer id: 0" failures or corruption of index contents during replication.
* Fix recovery from base backup when the starting checkpoint WAL record is not in the same WAL segment as its redo point
* Fix corner-case bug when streaming replication is enabled immediately after creating the master database cluster
* Fix persistent slowdown of autovacuum workers when multiple workers remain active for a long time The effective vacuum_cost_limit for an autovacuum worker could drop to nearly zero if it processed enough tables, causing it to run extremely slowly.
* Fix long-term memory leak in autovacuum launcher
* Avoid failure when trying to report an impending transaction wraparound condition from outside a transaction This oversight prevented recovery after transaction wraparound got too close, because database startup processing would fail.
* Add support for detecting register-stack overrun on IA64 The IA64 architecture has two hardware stacks. Full prevention of stack-overrun failures requires checking both.
* Add a check for stack overflow in copyObject() Certain code paths could crash due to stack overflow given a sufficiently complex query.
* Fix detection of page splits in temporary GiST indexes It is possible to have a "concurrent" page split in a temporary index, if for example there is an open cursor scanning the index when an insertion is done. GiST failed to detect this case and hence could deliver wrong results when execution of the cursor continued.
* Fix error checking during early connection processing The check for too many child processes was skipped in some cases, possibly leading to postmaster crash when attempting to add the new child process to fixed-size arrays.
* Improve efficiency of window functions Certain cases where a large number of tuples needed to be read in advance, but work_mem was large enough to allow them all to be held in memory, were unexpectedly slow. percent_rank(), cume_dist() and ntile() in particular were subject to this problem.
* Avoid memory leakage while ANALYZE'ing complex index expressions
* Ensure an index that uses a whole-row Var still depends on its table An index declared like create index i on t (foo(t.*)) would not automatically get dropped when its table was dropped.
* Add missing support in DROP OWNED BY for removing foreign data wrapper/server privileges belonging to a user
* Do not "inline" a SQL function with multiple OUT parameters This avoids a possible crash due to loss of information about the expected result rowtype.
* Fix crash when inline-ing a set-returning function whose argument list contains a reference to an inline-able user function
* Behave correctly if ORDER BY, LIMIT, FOR UPDATE, or WITH is attached to the VALUES part of INSERT ... VALUES
* Make the OFF keyword unreserved (Heikki Linnakangas) This prevents problems with using off as a variable name in PL/pgSQL. That worked before 9.0, but was now broken because PL/pgSQL now treats all core reserved words as reserved.
* Fix constant-folding of COALESCE() expressions The planner would sometimes attempt to evaluate sub-expressions that in fact could never be reached, possibly leading to unexpected errors.
* Fix "could not find pathkey item to sort" planner failure with comparison of whole-row Vars
* Fix postmaster crash when connection acceptance (accept() or one of the calls made immediately after it) fails, and the postmaster was compiled with GSSAPI support
* Retry after receiving an invalid response packet from a RADIUS authentication server This fixes a low-risk potential denial of service condition.
* Fix missed unlink of temporary files when log_temp_files is active If an error occurred while attempting to emit the log message, the unlink was not done, resulting in accumulation of temp files.
* Add print functionality for InhRelation nodes This avoids a failure when debug_print_parse is enabled and certain types of query are executed.
* Fix incorrect calculation of distance from a point to a horizontal line segment This bug affected several different geometric distance-measurement operators.
* Fix incorrect calculation of transaction status in ecpg
* Fix errors in psql's Unicode-escape support
* Speed up parallel pg_restore when the archive contains many large objects (blobs)
* Fix PL/pgSQL's handling of "simple" expressions to not fail in recursion or error-recovery cases
* Fix PL/pgSQL's error reporting for no-such-column cases As of 9.0, it would sometimes report "missing FROM-clause entry for table foo" when "record foo has no field bar" would be more appropriate.
* Fix PL/Python to honor typmod (i.e., length or precision restrictions) when assigning to tuple fields This fixes a regression from 8.4.
* Fix PL/Python's handling of set-returning functions Attempts to call SPI functions within the iterator generating a set result would fail.
* Fix bug in contrib/cube's GiST picksplit algorithm This could result in considerable inefficiency, though not actually incorrect answers, in a GiST index on a cube column. If you have such an index, consider REINDEXing it after installing this update.
* Don't emit "identifier will be truncated" notices in contrib/dblink except when creating new connections
* Fix potential coredump on missing public key in contrib/pgcrypto
* Fix buffer overrun in contrib/pg_upgrade
* Fix memory leak in contrib/xml2's XPath query functions
* Update time zone data files to tzdata release 2010o for DST law changes in Fiji and Samoa; also historical corrections for Hong Kong.