2. 日期/时间函数: 3. EXTRACT,date_part函数支持的field: 时间差 字段used_time与字段add_time的分钟间隔差 date_part('MINUTE',used_time::TIMESTAMP-add_time::TIMESTAMP)
NEW.manu_value; --return null because main table does not really contain data return NULL; END; $BODY$ LANGUAGE plpgsql VOLATILE COST 100; ALTER FUNCTION on_insert_base_table_machine2() OWNER TO postgres; 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18....
请注意,这些示例假设您已经连接到了 PostgreSQL 数据库。如果您的数据库连接设置不同,请确保在config/database.php文件中正确配置您的连接信息。
但在很多情况下,它可能会导致严重的性能损失和拖累整体吞吐量。相当长一段时间,我试图对这种开销进行良好的评估,之前写过how the volume of data transmission as part of SQL execution, as well as the cursor location, affects the overall performance: https://www.percona.com/blog/impact-of-network-and-...
https://github.com/citusdata/cstore_fdw 在CitusData公司内部,有一个基于cstore_fdw列存储引擎的项目,该项目通过PostgreSQL执行器的钩子接口,开发了一套基于cstore列存储的向量化执行器。数据聚合有4到6倍的性能提升,分组聚合有3倍的性能提升。 https://github.com/citusdata/postgres_vectorization_test 另一个项...
These are both database replication problems, but the best way to solve them is very different. And as you can see from these examples, replication has a lot of specific terminology that you'll have to understand to figure out what class of solution makes sense for your requirements. A gre...
SELECT b.relname, A.pid, A.locktype, A.DATABASE, A.MODE, A.relation FROM pg_locks A JOIN pg_class b ON A.relation=b.oid WHERE b.relname IN ('yy_dwzz_bf','hz_qtzf_yy','inc_cert_yy','inc_apply_yy','pay_plan_voucher_yy','bas_agency_info_yy','pay_voucher_yy','pay_vo...
The crucial part is that your function is there to perform additional checks, not just by-pass the security - so you could write a function which exports the exact data you need, or you could write something which can accept various options as long as they meet a strict whitelist. You ne...
相对于老版本的pg_basebackup多了backup_mainfest文件。该备份将PGDATA下的内容拷贝到/var/tmp/backups下。如果修改下冲突配置项,比如端口配置port,则可以通过pg_ctl -D /var/tmp/backups start直接启动。 当然,也可以备份成.tar文件: 代码语言:javascript ...
Backup restore method: pg_dump and pg_restore, first carefully explain these two commands, and then record my operation method.Pg_dump -- extracts an PostgreSQL database into a script file or other archive file Pg_dump [option...] [dbname]Option option...The following command line parameters...