databases Online Quiz - 37

Description: databases Online Quiz - 37
Number of Questions: 20
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Tags: databases
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  1. Deptno column has 5 distinct values, each having 200 rows

  2. Grade column has 2 distinct values having 1 and 999 rows

  3. Location column has 3 distinct values having 300, 400 and 300 rows

  4. All columns have same skewness

Correct Option: B
  1. SQL is executed one statement at a time. PL/SQL is executed as a block of code.

  2. SQL tells the database what to do (declarative), not how to do it. In contrast, PL/SQL tell the database how to do things (procedural).

  3. SQL is used to code queries, DML and DDL statements. PL/SQL is used to code program blocks, triggers, functions, procedures and packages.

  4. You can embed SQL in a PL/SQL program, but you cannot embed PL/SQL within a SQL statement.

Correct Option: A,B,C,D
  1. Scenario 1 : Distinct values for TableA.ColumnA = 10 Total no. of rows for TableA = 100

  2. Scenario 2 : Distinct values for TableA.ColumnB = 20 Total no. of rows for TableA = 100

  3. Scenario 3 : Distinct values for TableA.ColumnC = 30 Total no. of rows for TableA = 100

  4. Distinct values have no corelation to cardinality

Correct Option: C
  1. None of the below

  2. Both C & D

  3. ROWID is not a physical column.

  4. ROWID is the logical address of a row.

Correct Option: B
  1. variables and constants

  2. cursors

  3. exceptions

  4. All of the above

Correct Option: D
  1. System Variable

  2. System Function

  3. Both A & B

  4. None of the Above

Correct Option: B
  1. Use FULL hint to optimizer for full table scan

  2. Use INDEX or AND-EQUAL hint to optimizer to use one index or set to indexes instead of another.

  3. Use an expression in the Where Clause of the SQL.

  4. Disable Index on the column

Correct Option: A,B,C,D
  1. Record type declaration.

  2. Opening and parsing of SQL statements.

  3. Fetches records from cursor.

  4. Requires exit condition to be defined.

Correct Option: D
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