Oracle Database 12c: Multitenancy Essentials — Question 15

Which two completely prevent a Smart Scan from occurring?

Answer options

• A. querying a table containing many chained rows
• B. querying a table containing many migrated rows
• C. performing a minimum or maximum function on an indexed column
• D. performing a Fast Full Index scan on a reverse key index
• E. referencing more than 255 columns form an OLTP compressed table in a query
• F. querying a table containing a JSON column

Correct answer: B, E

Explanation

The correct answers are B and E because querying a table with many migrated rows and referencing more than 255 columns from an OLTP compressed table both prevent Smart Scans from executing. The other options may affect performance but do not completely inhibit a Smart Scan.