perl - 关于 DBD::Pg 的 AutoCommit，文档是否存在谎言？

Question

来自docs :

According to the DBI specification the default for AutoCommit is a true value. In this mode, any change to the database becomes valid immediately. Any BEGIN, COMMIT or ROLLBACK statements will be rejected. DBD::Pg implements AutoCommit by issuing a BEGIN statement immediately before executing a statement, and a COMMIT afterwards.

我的测试脚本:

#!/usr/bin/perl

use strict;
use warnings;
use DBI;

my $dbh = DBI->connect("dbi:Pg:dbname=test");
print "AutoCommit = $dbh->{AutoCommit}\n";
$dbh->do('INSERT INTO foo(x) VALUES (1)');

脚本输出:

AutoCommit = 1

还有我的日志(log_statement = 'all'):

2012-03-05 20:21:02 CST rootLOG: statement: INSERT INTO foo(x) VALUES (1)

(请原谅我以 root 身份测试我的脚本!)

DBD::Pg 文档向我 promise 的 BEGIN 和 COMMIT 在哪里？

Answer 1

我猜测 AutoCommit=1 所做的是在服务器端将 session 标记为 AUTOCOMMIT，请参阅 http://www.postgresql.org/docs/9.1/static/ecpg-sql-set-autocommit.html .不过，为了确保我们必须查看 dbi::Pg 源代码。