不支持跨大版本建立跨云或跨Region容灾关系。调用配置主实例容灾接口后直至成功搭建容灾关系,不能进行规格变更、主备倒换操作。搭建容灾后,灾备实例支持变更CPU和内存规格。修改主实例的端口或内网地址后需要重新搭建灾备关系。灾备实例搭建成功后,不能进行小版本升级。RDS for PostgreSQL 12及以上支持建立跨Region容灾关系。主实例参数被修改后,灾备实例无法同步修改该参数,需结合业务自行修改灾备实例参数。
teledb=# set max_parallel_workers_per_gather to 0; SET Time: 0.214 ms teledb=# select count(1) from t_count; count ---------- 20000000 (1 row) Time: 2700.569 ms (00:02.701) teledb=# set max_parallel_workers_per_gather to 2; SET Time: 0.269 ms teledb=#
teledb=# set max_parallel_workers_per_gather to 0; SET Time: 0.214 ms teledb=# select count(1) from t_count; count ---------- 20000000 (1 row) Time: 2700.569 ms (00:02.701) teledb=# set max_parallel_workers_per_gather to 2; SET Time: 0.269 ms teledb=#
teledb=# set max_parallel_workers_per_gather to 0; SET Time: 0.214 ms teledb=# select count(1) from t_count; count ---------- 20000000 (1 row) Time: 2700.569 ms (00:02.701) teledb=# set max_parallel_workers_per_gather to 2; SET Time: 0.269 ms teledb=#
teledb=# set max_parallel_workers_per_gather to 0; SET Time: 0.214 ms teledb=# select count(1) from t_count; count ---------- 20000000 (1 row) Time: 2700.569 ms (00:02.701) teledb=# set max_parallel_workers_per_gather to 2; SET Time: 0.269 ms teledb=#
teledb=# set max_parallel_workers_per_gather to 0; SET Time: 0.214 ms teledb=# select count(1) from t_count; count ---------- 20000000 (1 row) Time: 2700.569 ms (00:02.701) teledb=# set max_parallel_workers_per_gather to 2; SET Time: 0.269 ms teledb=#
teledb=# set max_parallel_workers_per_gather to 0; SET Time: 0.214 ms teledb=# select count(1) from t_count; count ---------- 20000000 (1 row) Time: 2700.569 ms (00:02.701) teledb=# set max_parallel_workers_per_gather to 2; SET Time: 0.269 ms teledb=#