IBM Exam Questions & Answers

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1 IBM Exam Questions & Answers Number: Passing Score: 800 Time Limit: 120 min File Version: IBM Exam Questions & Answers Exam Name: IBM PureData System for Analytics v7.0

2 Selftestengine QUESTION 1 A SELECT statement spends all its time returning 1 billion rows. What can be done to make this faster? A. Use a CURSOR B. Use an EXTERNAL TABLE C. Use the COPY command D. Increase PreFetch Count Use an EXTERNAL TABLE CREATE EXTERNAL TABLE <table_name> [SAMEAS table_name] ([column_name [,...]]) USING (DATAOBJECT (<file_path>) [MODE truncate append][delimiter <delimiter>]); Example: CREATE EXTERNAL TABLE customer_ext SAMEAS customer USING (DATAOBJECT ('/tmp/customer.unl') DELIMITER ' '); --load data to Ext table INSERT INTO customer_ext SELECT * FROM customer; QUESTION 2 What function can nzbackup perform? A. Back up pg.log files. B. Back up TEMP tables. C. Back up host data (catalog metadata). D. Back up the data using the specified number of streams. Note: Answer C is incorrect : to back up host data use - nzhostbackup command QUESTION 3 When loading a local ASCII file into table via an external table, where can the SQL be submitted? A. From a User Defined Function. B. From a JDBC application networked to the system. C. From nzsql on an AIX machine networked to the system. D. From nzsql on Microsoft Windows networked to the system.

3 QUESTION 4 You have access to two databases, DEV and PROD. Currently you are connected to the DEV database. Which operation is permitted? A. Delete from PROD..TableA B. Select * from PROD..TableA C. Truncate table PROD..TableA D. Insert into PROD..TableA select * from DEV..TableB NPS supports cross database access to referenced objects, tables and views on the same (within a single) Netezza system. There is no impact on performance whether the objects are in the same or different databases. Server to server cross database access is not supported as cross database join performance is not optimal. Cross database access support is limited to SELECT (queries) only and does not support INSERT, UPDATE and DELETE operations of referenced objects. However cross database access does allow SELECT... FROM clauses to include INSERT, DELETE, UPDATE, CTAS statements, joins, set operations, aggregations, sub-selects, and view definitions on the current database. The current database is the database that nzsql is connected to. QUESTION 5 Which statement is true? A. MATERIALIZED VIEWS can be run against EXTERNAL tables B. GENERATE STATISTICS can be run against EXTERNAL tables. C. EXTERNAL table data is deleted using the SQL DELETE command. D. EXTERNAL tables can be used to unload data to a Microsoft Windows directory. An EXTERNAL TABLE is a data file on disk that supports a schema definition, unload data to a external disk file and can be further processed using nzsql SQL. External tables provide e functionality to unload database table data to an external disk file or load data from an external disk file into a database table. B You cannot specify an external, temporary, system, or a clustered base table (CBT) as a base table for the view.

4 QUESTION 6 Given a plan ID, how would you obtain the query execution plan? (Choose two.) A. Turn ODBC tracing ON. B. Issue "SELECT * FROM _V_SESSION;" C. Go to the query history within the Windows NzAdmin GUI tool. D. Run EXECUTION PLAN before the query has been submitted. E. Issue "SHOW PLANFILE <nn>;" after the query has been submitted. Correct Answer: CE _V_SESSION provides the following information: ID, PID, UserName, Database, ConnectTime, ConnStatus, and LastCommand and it DOES NOT provide query execution plan QUESTION 7 When is the ToplogyImbalance event triggered? A. When a SAS switch has failed. B. When the path the path between an S-Blade and its disks has failed. C. When a disk enclosure's voltage sensor is reading outside the nominal range. D. When an S-Blade has ownership of more dataslices than is optimal (usually following a disk replacement). QUESTION 8 The query history data collected DOES NOT provide insight to which of the type of performance and behavior questions? A. The typical or most common types of queries. B. The longest and shortest running queries on the system. C. The queries submitted by specific users or groups of users. D. The rotational speed of the disk drives during query execution. QUESTION 9 When setting up a crontab entry, what must be done on a PureData System for Analytics server? A. Create an nzcron event.

5 B. nzstop/nzstart the database. C. Stop and start the appliance. D. Add entry to active host and standby host. QUESTION 10 Which High-Availability (HA) mechanism is used by the PureData System for Analytics Appliance? A. AIX-HA B. Linux-HA C. SuSE-HA D. Solaris-HA The Netezza high availability (HA) solution uses Linux-HA and Distributed Replicated Block Device (DRBD) as the foundation for cluster management and data mirroring. The host server (often referred to as host within the documentation) is a Linux server that runs the Netezza software and utilities QUESTION 11 Which condition will interrupt a query running on a fully operational PureData System for Analytics? A. One fan fails. B. One disk fails. C. Active host fails. D. One power supply fails. Correct Answer: C QUESTION 12 TableA is currently being accessed in a number of long running queries. Which of the following operations is NOT blocked, thus allowing the operation to immediately proceed? A. DROP TABLE TableA B. ALTER TABLE TableA C. TRUNCATE TABLE TableA D. GRANT SELECT ON TableA TO UserA

6 If the table is in use by an active query, the ALTER command will wait until that query completes. QUESTION 13 If 'admin' user is running a query, what percentage of resources are available when Guaranteed Resource Allocation (GRA) is Enabled? A. The maximum GRA assigned to the ADMIN group. B. The maximum GRA assigned to the PUBLIC group. C. 100% of the resources while other resource groups are active. D. Typically half of the resources while other resource groups are active The Netezza admin user account has a unique and powerful impact on the system and the GRA allocations. By default, the admin user is allocated 100 resource sharing points, which means that the admin user typically receives half of the available system resources when other RSGs are active, and 100% of the system resources when no other RSGs are busy. QUESTION 14 When a temporary table is created, where will the data be stored? A. On the host under the /nz/tmp directory. B. On the S-Blades under the data partition. C. Held in physical memory on the S-Blades. D. On the S-Blades under the swap partition. QUESTION 15 Why is table skew important to manage? A. Low table skew negatively impacts performance. B. High table skew negatively impacts performance. C. Low table skew negatively impacts data compression. D. Deleted rows consume disk space until they are freed. QUESTION 16

7 Which statement is true regarding the compress engine? A. Data automatically gets compressed. B. Columns to be compressed must be defined. C. The nzcompress utility must be run to compress the table. D. The nzcompress utility must be run to compress the database. QUESTION 17 The PureData System for Analytics implements which level of transaction isolation? A. Serializable B. Committed read C. Repeatable read D. Uncommitted read QUESTION 18 Which two statements are true about queries on the PureData System for Analytics Appliance? (Choose two.) A. Queries are executed in parallel by the host. B. Queries must be compressed before they can be executed. C. Queries are compiled into snippets and executed in parallel by the S-Blades. D. Queries must be uncompressed by the user and executed in parallel by the host. E. A query is compiled into a snippet which is executed across all available S-Blades. Correct Answer: CE QUESTION 19 Where are the database log files located? A. /var/log B. /usr/local C. /nz/kit/log D. The SYSTEM database Correct Answer: C

8 The postgres log file is the main database log file. It contains information about database activities. Log file /nz/kit/log/postgres/pg.log Current log /nz/kit/log/postgres/pg.log.n Archived log QUESTION 20 OLE-DB based applications on UNIX requires which PureData System for Analytics software? A. Install the JDBC driver for UNIX. B. Install the ODBC driver for UNIX. C. Install the OLE-DB driver for UNIX. D. OLE-DB is not supported on UNIX. QUESTION 21 In order for an ODBC application running on Microsoft Windows to connect to PureData System for Analytics, which two steps must be performed? (Choose two.) A. Install nzsql for Windows. B. Install nzadmin for Windows. C. Install an ODBC driver for Windows. D. Install an ODBC Driver Manager for Windows. E. Create or modify a Data Source Name (DSN) for a connection to a database. Correct Answer: CE QUESTION 22 Which command is used to display operational statistics about system capacity, faults, and performance? A. nzstats B. nzstate C. nzshow D. nzsystem CORRECT- A The nzstats command displays operational statistics about system capacity, faults, and performance. Operational statistics provide you with the following information: A high-level overview of how your system is running in a context of recent system activity

9 Details so that you can diagnose problems, understand performance characteristics, and interface to system management software Note: The terms group and table are based on Simple Network Management Protocol (SNMP) concepts and are not associated with Netezza database groups or tables. INCORRECT Use the nzstate command to display the current system state or to wait for a particular sys- tem state to occur. Use the nzsystem command to change the system state, and show and set configuration information. QUESTION 23 Which command allows you to show information about the database hardware as well as take actions such as activate or deactivate components, locate components, or delete them from the system? A. sar B. nzhw C. nzsystem D. nzinventory CORRECT Use the nzhw command to manage the hardware of the Netezza system. The command allows you to show information about the system hardware as well as take actions such as activate o deactivate components, locate components, or delete them from the system. nzhw [-h -rev] [-hc] subcmd [subcmd options] INCORRECT Use the nzsystem command to change the system state, and show and set configuration information. nzinventory This command is obsolete in Release 5.0. User nzhw instead QUESTION 24 What is the only predefined database user, which is able to access all objects and perform all tasks against the database? A. root B. public C. admin D. system Correct Answer: C QUESTION 25 What operating system runs on a PureData System for Analytics host?

10 A. AIX B. SUSE Linux C. Nucleus OS D. Redhat Linux QUESTION 26 What PureData System for Analytics component is responsible for controlling table storage? A. S-Blade (Snippet-Blade) B. SFI (Switching Fabric Interface) C. FPGA (Field Programmable Gate Array) D. DRBD (Distributed Replicated Block Device) QUESTION 27 Why should you avoid using Boolean data types as a distribution key for a table? A. Table will not join. B. Table will not broadcast. C. Table is likely to be skewed. D. Table is likely to be evenly spread across data slices. Correct Answer: C QUESTION 28 What will prevent a GROOM TABLE command from running on a table named TableA? A. If there are any materialized views on the table TableA. B. If there are any active selects running against the table TableA. C. If there are any active nzloads running against the table TableA. D. f there are any active updates running against the table TableA.

11 QUESTION 29 What two characteristics can be changed when using the CREATE TABLE AS (CTAS) statement to copy TableA to TableB? (Choose two.) A. The views on TableA. B. The privileges on TableA. C. The distribution key of TableB. D. The materialized views on TableB. E. The order of the data stored in TableB. Correct Answer: CE QUESTION 30 What is the host Linux file that must be modified to adjust optimizer settings permanently? A. /nz/data/postgresql.conf B. /nz/data/config/system.cfg C. /nz/kit/sys/inittopology.cfg D. /nz/kit/sys/inittopology.cfg QUESTION 31 Which statement is true about the groom feature? A. Groom allows the user to add row level security. B. Groom validates primary key constraints on the table. C. Groom reorders rows based on the DISTRIBUTE ON clause. D. Groom allows the user to reorganize tables based on the ORGANIZE ON clause. Starting in Release 6.0, you use the GROOM TABLE command to maintain the user tables by reclaiming disk space for deleted or outdated rows, as well as to reorganize the tables by their organizing keys. The GROOM TABLE command processes and reorganizes the table records in each data slice in a series of steps. Users can perform tasks such as SELECT, UPDATE, DELETE, and INSERT operations while the online data grooming is taking place. The SELECT operations run in parallel with the groom operations; any INSERT, UPDATE, and DELETE operations run serially between the groom steps. QUESTION 32

12 Why is generating statistics on a table important to query performance? A. The table statistics are used to facilitate disk space reclamation of deleted rows. B. The optimizer uses statistics to determine the optimal execution plan for queries. C. The Zone Map information cross references the table statistics for each column to avoid scanning. D. The Field Programmable Gate Array (FPGA) utilizes the statistics to identify which row/columns to filter. For the system to create the best execution plan for a query, it must make some decisions based on what it knows about the database tables it is accessing. Without up-to-date statis- tics the system uses internal, default values that are independent of the actual table and which result in suboptimal queries with long run times. Per table Number of records Per column Minimum value Maximum value Null counts (per column) Number of distinct values (also called dispersion) The admin user can assign other users this privilege. For example, to give user1 privilege to run GENERATE STATISTICS on one or all tables in the DEV database, the admin user must grant user1 LIST privilege on tables in the system database, and GENSTATS from the dev database, as in these sample SQL commands: SYSTEM(ADMIN)=> GRANT LIST ON TABLE TO user1; DEV(ADMIN)=> GRANT GENSTATS ON TABLE TO user1; QUESTION 33 Using a date column as a distribution key may distribute rows evenly across dataslices, why is this a poor choice of a distribution key? A. Queries on the table will invoke compression. B. Queries on date range may involve processing skew. C. Queries on date range will utilize only host processing. D. Queries on the table will invoke compression on the date columns. QUESTION 34 You have created a group GroupA with JOB MAXIMUM of 4, which statement is true? A. No more than 4 users can be assigned to GroupA. B. If users in GroupA submit more than 4 queries they will fail. C. If users in GroupA submit more than 4 queries, then they will queue in order. D. The job maximum cannot be less than the default concurrent query limit of 48. Correct Answer: C

13 QUESTION 35 Which CREATE DATABASE attributes are required? A. The database name. B. The database name and the redo log file name. C. The database name and the table space name. D. The database name and the temporary table space name. QUESTION 36 Which statement is true for database users and groups? A. All users must belong to admin group. B. Creation of users and groups is not allowed. C. Users and groups are local and tied to a particular database. D. Users and groups are global and not tied to a particular database. QUESTION 37 When creating a table, you can specify a column constraint for each individual column of either "NULL" or "NOT NULL". When column values are later evaluated within a query statement, which of these is true? A. 0 is equal to null, the empty string ( '' ) is equal to null. B. 0 is equal to null, the empty string ( '' ) is not equal to null. C. 0 is not equal to null, the empty string ( '' ) is equal to null. D. 0 is not equal to null, the empty string ( '' ) is not equal to null. QUESTION 38 What is a benefit of Clustered Base Tables? A. Replicates base table data. B. An alternate way to order a table's data. C. Materializes on disk joins between tables.

14 D. Increases the performance of load operations. QUESTION 39 Which of the following is a valid datatype definition? A. TEXT B. CLOB C. CHAR(64000) D. NUMERIC(1,38) Correct Answer: C CHAR(n) n <=64000 INCORRECT: numeric(p, s) p>s Numeric with precision p and scale s. Precision can range from 1 to 38, scale from 0 to the precision, e.g. numeric(18, 5) Netezza supports only 2 binary data types: VARBINARY(n), ST_GEOMETRY(n) QUESTION 40 Columns in a table may be zonemapped. How are those columns chosen? A. They are automatically selected by the system. B. They are based on the same columns as the table's distribution key. C. They are added via the ALTER TABLE ADD INDEX(column_name) statement. D. They are added via the ALTER TABLE ADD ZONEMAP(column_name) statement. QUESTION 41 When doing a CREATE SEQUENCE, the largest "maximum value" is based on what? A. BIGINT B. FLOAT8 C. NUMERIC(38,0) D. VARCHAR(256)

15 A sequence value is an integer that you can use wherever you would use numeric values. Netezza supports user sequences for the four integer types: byteint, smallint, integer, and bigint. CREATE SEQUENCE <sequence name> [as <data type> <options>] Where the options are the following: START WITH <start value> INCREMENT BY <increment> no minvalue minvalue <minimum value> no maxvalue maxvalue <maximum value> cycle no cycle QUESTION 42 Which procedural logic is NOT supported by NZPLSQL? A. Scrollable Cursors B. Looping (while, for) C. Conditionals (if/else) D. Returning a scalar result or a result set QUESTION 43 What is the maximum number of columns you can choose as organizing keys for clustered base table? A. 1 B. 2 C. 4 D. 8 Correct Answer: C A clustered base table (CBT) is a user table that contains data which is organized using one to four organizing keys. An organizing key is a column of the table that you specify for clustering the table records; Netezza uses the organizing keys to group records within the table and save them in the same or nearby extents. Netezza also creates zone maps for the organizing columns to accelerate the performance of queries on that table that restrict using the organizing keys. QUESTION 44 Which statement is true regarding the compress engine? A. Compression ratio is data dependent. B. Compression is performed by the host.

16 C. Compression degrades data scan speeds. D. Compression is performed by the SAS switches. QUESTION 45 What two types of notification can be configured for an event? (Choose two.) A. Insert a row into TableA. B. Run a stored procedure. C. Run a command on the active Host. D. Send an to a list of addresses. E. Send a Simple Network Message Protocol (SNMP) event. Correct Answer: CD When an event occurs, you can have the system send an message or execute an external command QUESTION 46 What is the fastest join utilized by PureData System for Analytics? A. Hash join. B. Merge join. C. Expression join. D. Cross product join. QUESTION 47 In a UNIX 64bit environment, a 64bit application requires which software to execute SQL statements via ODBC? (Choose two.) A. nzsql B. An ODBC driver manager. C. The system does not support 64 bit ODBC. D. A 64-bit ODBC driver for the same UNIX environment. E. A 32-bit ODBC driver for the same UNIX environment. D

17 QUESTION 48 A stored procedure returning one value is created, which two methods can be used to execute the procedure? (Choose two.) A. Using the EXECUTE command. B. Using the SELECT statement within a FROM clause. C. Using the SELECT statement within a HAVING clause. D. Using the SELECT statement without a FROM clause. E. Using the SELECT statement with tables in the FROM clause. D QUESTION 49 Which two commands can be used to shut the database system down? (Choose two.) A. nzstop B. nzdown C. nzhw stop D. nzsystem stop E. service halt nps D CORRECT: Use either the nzsystem stop or the nzstop command to stop system operation. The nzstop command is a script that initiates a system stop by halting all processing. Note: You must run nzstop while logged in as a valid Linux user such as nz on the host. You cannot run the command remotely. INCORRECT: Use the nzhw command to manage the hardware of the Netezza system. The command allows you to show information about the system hardware as well as take actions such as activate or deactivate components, locate components, or delete them from the system. QUESTION 50 What is nzconvert used for? A. To convert compressed external tables into ASCII text. B. To convert between character encodings before loading data. C. To translate stored procedures into NZPLSQL compatible syntax. D. To upgrade/downgrade the database to a different software version.

18 Use the nzconvert command to convert between any two encodings, between these encod- ings and UTF-8, and from UTF-32, -16, or -8 to NFC, for loading with the nzload command or external tables.