Programming Impact DS0-001 Practice Questions (Page 1)

Questions 1–5

1. 1foundation · easy

   Which of the following is a common technique used to validate and optimize SQL queries?

   • AUsing an execution plan to analyze query performance
   • BRewriting the query in a different programming language
   • CRunning the query on a separate test server without indexes
   • DCompiling the SQL code into a binary executable
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2. 2expert · hard

   A database administrator is validating a SQL query that uses a correlated subquery. The query returns correct results, but the DBA is concerned about performance. The subquery is executed for each row of the outer query. Which alternative approach would likely improve performance?

   • AAdd an index on the columns used in the outer query's WHERE clause.
   • BIncrease the database server's memory.
   • CUse a cursor to iterate through the results instead of a set-based operation.
   • DRewrite the correlated subquery as a JOIN with a derived table or a common table expression (CTE).
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4. 3foundation · easy

   Which database operation is most likely to cause high CPU usage on a database server?

   • AAn INSERT with a single row
   • BA DELETE with a WHERE clause on an indexed column
   • CA simple SELECT with a primary key lookup
   • DA complex query that performs a full table scan
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5. 4foundation · easy

   Which Hibernate annotation is used to map a Java class to a database table?

   • A@Table
   • B@Id
   • C@Entity
   • D@Column
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6. 5foundation · easy

   In Hibernate, what is the role of a Session object?

   • AIt stores the configuration settings for the Hibernate framework
   • BIt executes native SQL queries directly without using HQL
   • CIt defines the mapping between Java classes and database tables
   • DIt manages the connection between the Java application and the database
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