Test 3 Name: Mario Guimaraes Start time: November 22, 2005 12:43am Time allowed: 90 minutes Number of questions: 50 Question 1 (2 points) Which of the following statements is NOT true about the commit command: a. It releases all locks. b. When we type exit from the SQL prompt, the system performs an implicit commit c. When there is a power failure the system performs an implicit commit d. Commit ends a logical unit of work and confirms all the changes. Question 2 (2 points) What is the best solution for a DBA to do if there is a deadlock ? a. re-boot the system b. backup your database, drop your indexes and restore the database c. see what sessions are running and kill all the sessions involved in the deadlock except for one. d. defragment the disk Question 3 (2 points) Which of the following statements is NOT true about locks ? a. When we lock a record or a table in shared mode, no other transaction can update the record or table, but other transactions can access the record. b. An Update will typically lock in exclusive mode the records being modified. c. When we lock a record in shared mode , no other transaction can read (select) or update the record or table that is locked.Question 4 (2 points) Rollback will undo .. a. DML commands only b. DDL commands only c. DML and DDL commands. d. DML, DDL and DCM commands. Question 5 (2 points) Which is the best definition of Data Mining ? a. Any Analysis of Data performed by management. Typically done with On Line Analytical Processing Tools (OLAP). b. Knowledge Discovery. Consists of searching through data (typically a Datawarehouse) looking for patterns of data that will explain observed events, confirm hypothesis and explore new or unexpected relationships. Typically uses statistics, AI and computer graphics techniques. c. It consists of all the Analysis performed in a Datawarehouse Environment. d. Consists of working with Databases in Gold Mines. Typically this is done a lot in California and South Dakota. Gold Key IT Solutions has been a leader in this type of market. They own 47 % of the market. Gold Key’s main product is Goldfinger. Question 6 (2 points) Which of the following you would NOT expect (Not True statement)about a Datawarehouse a. expect more indexes, because indexes speed up query b. expect more Materialized Views c. Expect bigger block sizes d. Expect historic data e. Expect less money for employees, because the money is spent all in the DatawarehouseQuestion 7 (2 points) Which of the following is NOT a typical DBA task ? a. Startup & Shutdown Systems b. Backup & Restore Data c. Install new versions of the DBMS d. Grant/Revoke user’s access to tables and other objects. Download patches. e. Write Balanced Tree Indexes for DBMS optimization Question 8 (2 points) Which statement below is NOT true about the Extraction Transform and Load (ETL) process ? a. In the case of an Independent Datamart, where you have a separate ETL for each Datamart, the ETL part is simpler, but the Query Management is typically more complicated. b. The effort required to clean the datasources may increase exponentially as the number of overlapping datasources increases. c. Dropping the index, loading data into the datawarehouse and re-creating the index may be a good options because an index slows down any update operation (INSERT, UPDATE, DELETE). d. Several Independent Datamarts (as opposed to one Datawarehouse) makes Query Management much easier. Question 9 (2 points) Which of the following statements is NOT true about JDBC ? a. You may need to download a JDBC Driver for Oracle (typically from Oracle’s web-site). It is important that the JDBC driver is placed in the proper sub-directory. b. JDBC is a pre-defined set of classes and methods for accessing databases. You must download the proper JDBC driver for the specific DBMS you are working with. c. JDBC allows access to Relational Databases as Well as Non-Relational Databases d. JDBC is quite faster than SQLj.Question 10 (2 points) Which of the following objects allow you to read (through methods) an XML file, write to an XML file, read from a Table, and write to a table. a. Resultset or Recordset b. Cursor c. Dataset d. A View Question 11 (2 points) Which of the following is NOT true about ODBC, OLE-DB, ADO ? a. ODBC is a widely used protocol for accessing Relational Databases b. OLE-DB has the advantage over ODBC because it can be used to access Relational Data and non-relational Database c. ADO is a set objects that makes the interface to OLE-DB a lot easier d. Since ODBC is for Relational Databases only, it is a lot faster. Question 12 (2 points) What are the frequent operations of a Datawarehouse ? a. Insert, Update, Delete and Select b. All DDL and DML operations. c. Join-Merge and Nested Joins d. Select and Inserts in Batch (Load) Question 13 (2 points) Which of the following is NOT a mechanism to improve performance of your system ? a. Create Index b. Rewrite your SQL queries c. Change the Default Database Block size before installing your database d. Drop Index, Backup your Tables, Restore your Tables and Recreate Indexes e. Create ViewsQuestion 14 (2 points) Which of the following statements is NOT true about the commit command ? a. It releases all locks b. It is a logical write to disk. c. It is a physical write to disk d. Information (log buffer) is written to disk at time of commit. . Question 15 (2 points) Which is NOT true about pseudo files ? a. Cursor (PL/SQL, Embedded SQL), Resultset/Record (Java) set and Dataset (Visual Studios) are all example of pseudo files b. They are needed when the result of an SQL query may be more than one row. c. They are very useful for DML operations: Insert, Update, Delete and Select. Question 16 (2 points) How are the queries in a Datawarehouse different from the queries in an Operational Databases ? a. The queries are faster in a Datawarehouse b. The queries are slower in a Datawarehouse c. The Queries always involve searching through much bigger databases in a Datawarehouse. Operational Databases don’t have many records. d. The queries in a Datawarehouse are typically trying to retrieve many records while in an Operational