New to PostgreSQL? PostgreSQL is a powerful, open source object-relational database system with over 35 years of active development that has earned it a strong reputation for reliability, feature robustness, and
最高级别的锁,与所有模式的锁冲突,该锁保证持有者是访问该表的唯一事务。由DROP TABLE、TRUNCATE、REINDEX、CLUSTER、VACUUM FULL和REFRESH MATERIALIZED VIEW(不带CONCURRENTLY)命令获取。ALTER TABLE的某些命令也在会获得这种锁。同时,显式发出LOCK TABLE命令的默认锁模式也是该八级锁。 冲突级别:所有 值得注意的是savep...
这种架构下,读写分离是很好的,单写多读,减少冲突又提高了效率。 其他的高可用方案还可以参考各类数据库的多种部署模式,比如mysql的主从、双主多从、MHA;redis的主从,哨兵,cluster等等。 2、同城双活 前面讲到的几种方案,基本都是在一个局域网内进行的。业务发展到后面,有了同城多活的方案。和前面比起来,不信任...
查看libvirt服务是否启动成功。若服务处于“Active”状态,说明服务启动成功,可以正常使用libvirt提供的virsh命令行工具,命令和回显如下: $ systemctl status libvirtd ● libvirtd.service - Virtualization daemon Loaded: loaded (/usr/lib/systemd/system/libvirtd.service; enabled; vendor preset: enabled) Active: a...
ALTER TABLE、DROP TABLE、TRUNCATE、REINDEX、CLUSTER、VACUUM FULL和REFRESH MATERIALIZED VIEW(不带CONCURRENTLY)命令会获得。很多形式的ALTER INDEX和ALTER TABLE也在这个层面上获得锁。这也是未显式指定模式的LOCK TABLE命令的默认锁模式。 这种模式与所有模式的锁冲突。这种模式保持者是访问该表的唯一事务。
The database cluster will be initialized with locale "en_US.UTF-8". The default database encoding has accordingly been set to "UTF8". The default text search configuration will be set to "english". Data page checksums are disabled.
也就是说在这个会话未提交事务释放锁之前,我们不能做申请SHARE、SHARE ROW、ROW EXCLUSIVE、EXCLUSIVE和ACCESS EXCLUSIVE锁模式相关的操作,例如CREATE INDEX(不带CONCURRENTLY)、ALTER TABLE、DROP TABLE、TRUNCATE、REINDEX、CLUSTER、VACUUM FULL和REFRESH MATERIALIZED VIEW(不带CONCURRENTLY)等。
查看Postgresql容器日志,检查Postgresql数据库是否正常启动。 [root@docker ~]# docker logs postgres The files belonging to this database system will be owned by user"postgres". This user must also own the server process. The database cluster will be initialized with locale"en_US.utf8". ...
Hybrid, multi-cloud flexibility PGD is available for PostgreSQL, EDB Postgres Advanced Server (EPAS), and EDB Postgres Extended (PGE), for self-managed databases and Kubernetes environments. Unplanned outages protection PGD uses an active/active cluster architecture, conflict resolution via Raft-based ...
Active: active (running) since Sat 2016-11-26 22:49:07 CST; 1min 33s ago 切换到操作系统下的“postgres”用户,登录数据库 [root@node1 ~]# su - postgres -bash-4.2$ psql psql (9.2.15) Type "help" for help. postgres=# help