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DataBase Administrator (DBA) Interview Questions and Answers
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68. Which date function returns number value?
months_between
69. Any three PL/SQL Exceptions?
Too_many_rows, No_Data_Found, Value_Error, Zero_Error, Others
70. What are PL/SQL Cursor Exceptions?
Cursor_Already_Open, Invalid_Cursor
71. Other way to replace query result null value with a text
SQL> Set NULL ?N/A?
to reset SQL> Set NULL ??
72. What are the more common pseudo-columns?
SYSDATE, USER , UID, CURVAL, NEXTVAL, ROWID, ROWNUM
73. What is the output of SIGN function?
1 for positive value,
0 for Zero,
-1 for Negative value.
74. What is the maximum number of triggers, can apply to a single table?
12 triggers.
75. What is a database instance? Explain.
A database instance (Server) is a set of memory structure and background processes that access a set of database files. The processes can be shared by all of the users.
The memory structure that is used to store the most queried data from database. This helps up to improve database performance by decreasing the amount of I/O performed against data file.
76. What is Parallel Server?
Multiple instances accessing the same database (only in multi-CPU environments)
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