Oracle 下基于 DBMS_RESOURCE_MANAGER 包估算数据库存储 IO 性能
1.CALIBRATE_IO
使用 CALIBRATE_IO 存储过程估算数据库存储 IO 性能。该存储过程的输入输出如下。
| 参数名称 | 参数类型 | 参数描述 |
| num_physical_disks | IN | Approximate number of physical disks in the database storage |
| max_latency | IN |
Maximum tolerable latency in milliseconds for
database-block-sized IO requests |
| max_iops | OUT |
Maximum number of I/O requests per second that can be
sustained. The I/O requests |
| max_mbps | OUT |
Maximum throughput of I/O that can be sustained, expressed
in megabytes per second. The I/O requests are
randomly-distributed, 1 megabyte reads. |
| actual_latency | OUT |
Average latency of database-block-sized I/O requests at max_
iops rate, expressed in milliseconds |
测试语句类似如下。
SQL> set time on
set timing on
SET SERVEROUTPUT ON
DECLARE
lat INTEGER;
iops INTEGER;
mbps INTEGER;
BEGIN
DBMS_RESOURCE_MANAGER.CALIBRATE_IO (120, 10, iops, mbps, lat);
DBMS_OUTPUT.PUT_LINE ('max_iops = ' || iops);
DBMS_OUTPUT.PUT_LINE ('latency = ' || lat);
dbms_output.put_line('max_mbps = ' || mbps);
end;
/
注意：num_physical_disks 参数可设置较大，如果设置过小，将影响测试结果。当该值超过一定的限度后，估算的 IO 性能值将不再变化。
注意：同一时刻仅能执行一次估算（Only one calibration can be run at a time. If another calibration is initiated at the same time, it will fail.）
注意：对于 Oracle RAC 而言，负载将被均衡至各个节点（For an Oracle Real Application Clusters (Oracle RAC) database, the workload is simultaneously generated from all instances.）
参考文档：
《PLSQL Packages and Types Reference》