مساعدة بليز

Question 1:

Oracle9i has seven major types of tables. Briefly describe any five of them. Also answer the following questions related to the tables support your with explanations.

1. What is the maximum number of columns that a table can have?

2. What is the maximun number of rows that a table can have, and explain if there are limitations to this number with regards to other storage paramenters.

3. What is the maximum number of indexes that a table can have?

Question 2:

Your Oracle employee table contains many unique values in the FIRSTNAME column. You want to index that column to take advantage of this fact in query access. Which of the index will you use and why?

Question 3:

TRUNCATE TABLE department;

DROP TABLE department;

How will the results of two statements differ, explain?

Question 4:

You need to create a normal B-tree index on DEPT ID field of EMPLOYEE talbe. The records in the EMPLOYEE table are ordered by the EMP ID attribute. Which CREATE INDEX will you use, write the command to create the index.

Question 5:

Write the SQL statment that will display the names of all bitmap indexes which are currently invalid.

Question 6:

What is the difference between a unique index that supports a PRIMARY KEY constraint and unique index that supports a UNIQUE key constraint?

Question 7:

What is the difference between specifying REVERSE on an index and specifying DESC on an indexed column?

Question 8:

You have a table with an associated index. How is this index affected if the table is truncated with a DROP option?

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I changed my mind of two questions, I know the answers and the questions are very long lool :)

Hope u can help me as soon as possible :D