> For the complete documentation index, see [llms.txt](https://docs.postgresql.tw/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.postgresql.tw/appendixes/contrib/pgsurgery.md).

# F.34. pg\_surgery — 對關聯資料執行低階修復 \#

[F.34.1. 函式](#PGSURGERY-FUNCS)

[F.34.2. 作者](#PGSURGERY-AUTHORS)

`pg_surgery` 模組提供多種函式，可修復受損的關聯。這些函式在設計上並不安全，使用它們可能損毀（或進一步損毀）資料庫。例如，這些函式很容易使資料表與其索引不一致、導致 `UNIQUE` 或 `FOREIGN KEY` 限制條件違規，甚至使讀取時會造成資料庫伺服器當機的 tuple 變得可見。應極為謹慎地使用它們，且只應作為最後手段。

## F.34.1. 函式 [#](#PGSURGERY-FUNCS)

`heap_force_kill(regclass, tid[]) returns void` : `heap_force_kill` 不檢查 tuple，便將「已使用」的行指標標記為「死亡」。此函式的用途是強制移除其他方式無法存取的 tuple。例如：

````
```

test=> select * from t1 where ctid = '(0, 1)';
ERROR:  could not access status of transaction 4007513275
DETAIL:  Could not open file "pg_xact/0EED": No such file or directory.

test=# select heap_force_kill('t1'::regclass, ARRAY['(0, 1)']::tid[]);
 heap_force_kill
-----------------

(1 row)

test=# select * from t1 where ctid = '(0, 1)';
(0 rows)
```
````

`heap_force_freeze(regclass, tid[]) returns void` : `heap_force_freeze` 不檢查 tuple 資料，便將 tuple 標記為凍結。此函式的用途是讓因可見性資訊損毀而無法存取的 tuple 可被存取，或讓因可見性資訊損毀而無法成功執行清理的資料表得以清理。例如：

````
```

test=> vacuum t1;
ERROR:  found xmin 507 from before relfrozenxid 515
CONTEXT:  while scanning block 0 of relation "public.t1"

test=# select ctid from t1 where xmin = 507;
 ctid
-------
 (0,3)
(1 row)

test=# select heap_force_freeze('t1'::regclass, ARRAY['(0, 3)']::tid[]);
 heap_force_freeze
-------------------

(1 row)

test=# select ctid from t1 where xmin = 2;
 ctid
-------
 (0,3)
(1 row)
```
````

## F.34.2. 作者 [#](#PGSURGERY-AUTHORS)

Ashutosh Sharma `<ashu.coek88@gmail.com>`

***

原文：[PostgreSQL 18.6 Documentation](https://www.postgresql.org/docs/18/pgsurgery.html)（原文版本：18.6；核對日期：2026-09-06）


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