在PostgreSQL 8.4中安装其他模块多维数据集时出现问题

第一个任务是创建一个名为“book”的数据库,并检查contrib包是否已正确安装.

$createdb book
$psql book -c "SELECT '1'::cube;"

当我这样做,我得到以下输出：

ERROR:  type "cube" does not exist
LINE 1: SELECT '1'::cube;

我已经使用以下命令安装了多维数据集包：

$sudo -u postgres psql postgres < /usr/share/postgresql/8.4/contrib/cube.sql

我尝试重新启动PostgreSQL,但问题仍然存在.当我第二次尝试运行包导入时,我收到以下消息,其中明确指出类型“cube”已经存在：

SET
CREATE FUNCTION
CREATE FUNCTION
CREATE FUNCTION
CREATE FUNCTION
ERROR:  type "cube" already exists
COMMENT
CREATE FUNCTION
COMMENT
CREATE FUNCTION
COMMENT
CREATE FUNCTION
COMMENT
CREATE FUNCTION
COMMENT
CREATE FUNCTION
COMMENT
CREATE FUNCTION
COMMENT
CREATE FUNCTION
COMMENT
CREATE FUNCTION
COMMENT
CREATE FUNCTION
COMMENT
CREATE FUNCTION
COMMENT
CREATE FUNCTION
CREATE FUNCTION
CREATE FUNCTION
CREATE FUNCTION
CREATE FUNCTION
CREATE FUNCTION
CREATE FUNCTION
CREATE FUNCTION
CREATE FUNCTION
CREATE FUNCTION
CREATE FUNCTION
CREATE FUNCTION
CREATE FUNCTION
CREATE FUNCTION
ERROR:  operator < already exists
ERROR:  operator > already exists
ERROR:  operator <= already exists
ERROR:  operator >= already exists
ERROR:  operator && already exists
ERROR:  operator = already exists
ERROR:  operator <> already exists
ERROR:  operator @> already exists
ERROR:  operator <@ already exists
ERROR:  operator @ already exists
ERROR:  operator ~ already exists
CREATE FUNCTION
CREATE FUNCTION
CREATE FUNCTION
CREATE FUNCTION
CREATE FUNCTION
CREATE FUNCTION
CREATE FUNCTION
ERROR:  operator class "cube_ops" for access method "btree" already exists
ERROR:  operator class "gist_cube_ops" for access method "gist" already exists

那么我做错了什么？