PostgreSQL实时查看数据库实例正在执行的SQL语句实例详解寻技术

一、查询当前正在执行所有SQL语句

SELECT
	pid,
	datname,
	usename,
	client_addr,
	application_name,
	STATE,
	backend_start,
	xact_start,
	xact_stay,
	query_start,
	query_stay,
	REPLACE ( query, chr( 10 ), ' ' ) AS query 
FROM
	(
	SELECT
		pgsa.pid AS pid,
		pgsa.datname AS datname,
		pgsa.usename AS usename,
		pgsa.client_addr client_addr,
		pgsa.application_name AS application_name,
		pgsa.STATE AS STATE,
		pgsa.backend_start AS backend_start,
		pgsa.xact_start AS xact_start,
		EXTRACT ( epoch FROM ( now( ) - pgsa.xact_start ) ) AS xact_stay,
		pgsa.query_start AS query_start,
		EXTRACT ( epoch FROM ( now( ) - pgsa.query_start ) ) AS query_stay,
		pgsa.query AS query 
	FROM
		pg_stat_activity AS pgsa 
	WHERE
		pgsa.STATE != 'idle' 
		AND pgsa.STATE != 'idle in transaction' 
		AND pgsa.STATE != 'idle in transaction (aborted)' 
	) idleconnections 
ORDER BY
	query_stay DESC

二、判断是否存在慢查询语句

字段	解释
PID	数据库查询进程ID
query_stay	查询时长秒
query	查询SQL语句

三、按查询进程，杀掉慢查询释放资源

SELECT pg_terminate_backend(PID);
SELECT pg_terminate_backend(6289);

四、扩展query的显示长度能展示出全部语句

vi /var/lib/pgsql/12/data/postgresql.conf

修改track_activity_query_size的值重启数据库服务

五、杀掉某个数据库的所有数据库连接

SELECT pg_terminate_backend(pg_stat_activity.pid)FROM pg_stat_activity WHERE datname='数据库名称' AND pid<>pg_backend_pid();

六、导出数据库某个表

pg_dump -t 某个表名  "host=192.168.16.31  port=18921 user=postgres password=数据库密码  dbname=数据库"  -f /app/zjfbeifen/1.sql

七、shell脚本自动导入按表

touch insert_sql.sh

#!/bin/bash
. /etc/profile
. ~/.bash_profile
export PATH=/usr/pgsql-12/bin:/usr/bin;
export PGPASSWORD=数据库密码;psql -U postgres -d 数据库名称    < /mnt/nas/bak-06/1.sql;

指定postgres用户执行导入某个表的语句，免密执行shell脚本
touch nasen_insert.sql

#!/bin/sh
source /etc/profile
PATH=/usr/local/bin:$PATH
echo 'task_start'
runuser - postgres -g postgres -c "sh /data/test/insert_sql.sh"
echo 'task_finish'

定时器配置

00 10 * * * /usr/bin/sh /data/test/insert_nasen.sh >>/data/test/insert_nasen.log

八、shell脚本执行postgre的sql语句

touch drop01.sql

#删除某个表SQL语句

DROP TABLE IF EXISTS public.test;

touch drop.sh

#!/bin/bash
. /etc/profile
. ~/.bash_profile
export PATH=/usr/pgsql-12/bin:/usr/bin;
#su postgres
export PGPASSWORD=123456;psql -U postgres -d 数据库名称   < /data/test/drop01.sql;

touch nasen_drop.sh

#!/bin/bash
source /etc/profile
PATH=/usr/local/bin:$PATH

echo 'task_start'
runuser - postgres -g postgres -c "sh /data/test/drop.sh"
echo 'task_finish'

定时器调用

00 9 * * * /usr/bin/sh /data/test/drop_nasen.sh >>/data/test/drop_nasen.log

九、导出导入整个数据库

备份导出整个数据库

pg_dump -h localhost  -U postgres  -d riskDataCheck -Fc -f /soft/backup/20220321/test-0321.dump

导入某个数据库

pg_restore -h localhost -U postgres -d risk_agcloud_430000_1 /soft/backup/test-0321.dump

十、切换数据库存储路径迁移data目录

步骤1：创建新data目录

sudo mkdir /home/data

sudo chown -R postgres:postgres data

sudo chmod 700 data

步骤2：关闭数据库服务

systemctl stop postgresql-12

步骤3：执行复制

cp -rf /var/lib/pgsql/12/data/* /home/data              #这个路径是默认的在线安装postgresql12.11默认路径

sudo chown -R postgres:postgres data                #加这句是因为复制过来有的时候归属是ROOT用户，应该是postgres用户才对！

步骤4：修改服务配置文件

cd /usr/lib/systemd/system

vi postgresql-12.service                                         #默认的在线安装postgresql12.11服务名称

Environment=PGDATA=/home/data

步骤5：重新加载服务配置

systemctl daemon-reload

步骤6：重启数据库服务

systemctl start postgresql-12

步骤7：查看变更状态

 systemctl status postgresql-12

十一、安装PostGIS插件

步骤1：安装postgis的依赖包

rpm -ivh https://mirrors.aliyun.com/epel/epel-release-latest-7.noarch.rpm

步骤2：安装postgis

yum install postgis31_12.x86_64                                        #这个对版本有一些对应关系注意，这个命令对应的是12.X

步骤3：安装完毕后切换为postgres用户，开启扩展初始化操作

// 开启插件

# su postgres  
# psql  
// 开启pgsql的插件  
postgres=# create extension postgis;  
postgres=# create extension postgis_topology;  
postgres=# create extension fuzzystrmatch;  
postgres=# create extension address_standardizer;  
postgres=# create extension address_standardizer_data_us;  
postgres=# create extension postgis_tiger_geocoder; 
//查看版本，验证安装是否成功
postgres=# SELECT PostGIS_full_version();

步骤4：安装pgRouting

yum install pgrouting_12   #针对12.X版本

步骤5：检查插件是否完成

十二、安装uuid-ossp插件

postgres=# create extension “uuid-ossp”;
ERROR: could not open extension control file “/opt/pgsql12.2/share/extension/uuid-ossp.control”: No such file or directory

步骤1：安装uuid依赖包

 [root@Location-01 ~]# yum -y install e2fsprogs-devel uuid uuid-devel libuuid-devel

## 步骤2：执行编译配置

[root@Location-01 ~]# cd /usr/local/src/postgresql-12.2/
[root@Location-01 postgresql-12.2]# pwd
/usr/local/src/postgresql-12.2
[root@Location-01 postgresql-12.2]# ./configure --prefix=/opt/pgsql12.2 --with-uuid=ossp

步骤3：编译安装uuid-ossp

[root@Location-01 ~]# cd /usr/local/src/postgresql-12.2/contrib/uuid-ossp/
[root@Location-01 uuid-ossp]# pwd
/usr/local/src/postgresql-12.2/contrib/uuid-ossp
[root@Location-01 uuid-ossp]# make && make install

步骤4：检测是否成功

postgres=# create extension "uuid-ossp";
CREATE EXTENSION

postgres=# select * from pg_available_extensions;
    name    | default_version | installed_version |                     comment                     
------------+-----------------+-------------------+-------------------------------------------------
 plpgsql    | 1.0             | 1.0               | PL/pgSQL procedural language
 plperl     | 1.0             |                   | PL/Perl procedural language
 plperlu    | 1.0             |                   | PL/PerlU untrusted procedural language
 plpython2u | 1.0             |                   | PL/Python2U untrusted procedural language
 plpythonu  | 1.0             |                   | PL/PythonU untrusted procedural language
 uuid-ossp  | 1.1             |                   | generate universally unique identifiers (UUIDs)
(6 rows)