The database system can check the performance bottleneck, and write the widgets.

Receive company tasks, 3 single-machine databases of the same user are to be merged. Then the library module was completed on the basis of the previous functions. The actual guide to the library, found that the speed is getting slower. A total of 1700 items, initially, 1 hours and 200 items; hours later, 90 minutes 200 items; After one day, 1 hours 50 items; hours, 1 hours, 10 items.

Urgent, call the database administrator. He asked me to look at the V$session_event watch, but I didn't see it. The V$sqlarea table is easier to understand, so I looked at it,

Soon found that the operation was the same table, select COUNT (*), found more than 1 million rows of duplicate records. Problem found.

The database system can check the performance bottleneck, and write the widgets.