5.One of your databases supports an OLTP workload.
The default undo tablespace is fixed size with:
- RETENTION NOGUARANTEE
- undo_retention is 12 minutes
User scott get this error after a query on the sales table has run for more than 15 minutes:
ORA-01555: snapshot too old
Which three factors taken separately or in some combination might be the cause?
A) A committed delete to the sales table was made more than 12 minutes before the query began.
B) An uncommitted delete to the sales table was made more than 12 minutes before the query began.
C) A committed update to the sales table was made more than 12 minutes before the query began.
D) An uncommitted update to the sales table was made more than 12 minutes before the query began.
E) An update was made to the sales table before the query began.
F) An update to the SALES table was committed after the query began.
G) An update was made to the sales table after the query began.
Answer：ACF
(解析：题目的意思是：哪三个因素单独或结合在一起可能是原因?快照太老是因为一个长时间运行的查询语句，所要查询的对象在 undo 段找不到而产生的，找不到的原因是事务已经提交了，原来使用的 undo 段被覆盖。3组：1015267481 验证ocp)
原文地址：https://blog.51cto.com/13854012/2383747