transaction_read_only

• 19
• 18
• 17
• 16
• 15
• 14
• 13
• 12
• 11
• 10
• 9.6
• 9.5
• 9.4
• 9.3
• 9.2
• 9.1
• 9.0
• 8.4
• 8.3
• 8.2

transaction_read_only 的基本用法示例

postgres=# SHOW transaction_read_only;
 transaction_read_only 
-----------------------
 off
(1 row)

postgres=# SET default_transaction_read_only TO on;
SET

postgres=# SHOW transaction_read_only;
 transaction_read_only 
-----------------------
 on
(1 row)

在事务中更改 transaction_read_only 相当于执行 SET TRANSACTION READ WRITE 或 ... READ ONLY。

postgres=# SHOW transaction_read_only;
 transaction_read_only 
-----------------------
 on
(1 row)

postgres=# BEGIN;
BEGIN

postgres=*# SET transaction_read_only = off;
SET

postgres=*# INSERT INTO foo VALUES (1);
INSERT 0 1

postgres=*# COMMIT;
COMMIT

在备用服务器上无法设置 transaction_read_only

postgres=# SET transaction_read_only TO off;
ERROR:  cannot set transaction read-write mode during recovery

• PostgreSQL 文档: transaction_read_only