I have some questions regarding 1Z0-051. Can anyone help me please.
Different books have different material about following questions.
Q1-The delimeter is a single or multiple character?
Q2-What is default date format mask in oracle.
Q3-When a table is created with subquery, which constraints are copied to new table(in some book, it is only NULL constrain while in other books it is NULL and Check constraint).Also if a constraint is disable, will it be applied to new created table?
Q4-The columns used in JOING USING clause have the same datatype or not?
Q5- Can we use subqueries in GROUP BY or HAVING clause?
I will be very thankful if u help me.
Which books are you reading? If it is one of those that I wrote and you have found a mistake, please let me know and I'll get it added to the errata.
But, much more important, you need to improve your learning technique. All your questions can be ansered by simple tests, such as this for your Q3:
orclz> create table t1(c1 number not null,c2 number check (c2>0));
orclz> create table t2 as select * from t1;
orclz> select table_name,constraint_name,constraint_type from user_constraints
2 where table_name like 'T_';
You should never believe anything just because you have read it. Furthermore, you must experiment with everything as you read it. That way you will learn properly database administration, rather than memorizing answers to questions.
You'll find all the OCP exam guides here,
and there is also a large number of free recordings here
which are a lot more recent.