1z0-082 Practice Test

1z0-082 Practice Test practice questions, page 4 of 7, with answer review and explanations.

Question 16

Which three statements are true about dropping and unused columns in an Oracle database? (Choose three.)

  1. A primary key column referenced by another column as a foreign key can be dropped if using the CASCADE option.
  2. An UNUSED column's space is reclaimed automatically when the block containing that column is next queried.
  3. An UNUSED column's space is reclaimed automatically when the row containing that column is next queried.
  4. Partition key columns cannot be dropped.
  5. A DROP COLUMN command can be rolled back
  6. A column that is set to UNUSED still counts towards the limit of 1000 columns per table

Question 17

Which two statements are true regarding Oracle database space management within blocks managed by Automatic Segment Space Management (ASSM)? (Choose two.)

  1. PCTFREE defaults to 10% for all blocks in all segments for all compression methods
  2. ASSM assigns blocks to one of four fullness categories based on what percentage of the block is allocated for rows
  3. Update operations always attempt to find blocks with free space appropriate to the length of the row being updated
  4. Insert operations always attempt to find blocks with free space appropriate to the length of the row being inserted
  5. A block will always be eligible for inserts if the row is short enough to fit into the block

Question 18

Evaluate these commands which execute successfully: Which two statements are true about the ORD_ITEMS table and the ORD_SEQ sequence? (Choose two.)

  1. If sequence ORD_SEQ is dropped then the default value for column ORD_NO will be NULL for rows inserted into ORD_ITEMS
  2. Any user inserting rows into table ORD_ITEMS must have been granted access to sequence ORD_SEQ
  3. Column ORD_NO gets the next number from sequence ORD_SEQ whenever a row is inserted into ORD_ITEMS and no explicit value is given for ORD_NO
  4. Sequence ORD_SEQ cycles back to 1 after every 5000 numbers and can cycle 20 times
  5. Sequence ORD_SEQ is guaranteed not to generate duplicate numbers

Question 19

Which three instance situations are possible with the Oracle Database server without multi-tenant? (Choose three.)

  1. two or more instances on separate servers all associated with one database
  2. one instance on one server associated with one database
  3. one instance on one server associated with two or more databases on the same server
  4. one instance on one server not associated with any database
  5. one instance on one server associated with two or more databases on separate servers

Question 20

Which two statements are true about the ORDER BY clause when used with a SQL statement containing a SET operator such as UNION? (Choose two.)

  1. Column positions must be used in the ORDER BY clause
  2. Only column names from the first SELECT statement in the compound query are recognized
  3. The first column in the first SELECT of the compound query with the UNION operator is used by default to sort output in the absence of an ORDER BY clause
  4. Each SELECT statement in the compound query must have its own ORDER BY clause
  5. Each SELECT statement in the compound query can have its own ORDER BY clause