# HP Vertica Solutions [2012] v6.0

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Exam contains 50 questions

Which methods are available to optimize a projection for delete processing? (Select two.)

• A. Add a low cardinality column to the beginning of all projections on the source table.
• B. Add a high cardinality column to the end of all projections on the source table.
• C. Add all columns used as delete predicates to all projections on the source table.
• D. Add a low cardinality column to the end of all projections on the source table.
• E. Add a high cardinality column to the beginning of all projections on the source table.

What are the advantages of a merge join versus a hash join? (Select two.)

• A. Sometimes a merge join runs faster than a hash join.
• C. A merge join requires no optimization.
• D. A merge join can spill to disk if the inner table is too large.
• E. A merge join joins the data into a new projection.

Reference:https://my.vertica.com/docs/6.1.x/HTML/index.htm#20001.htm

If your CEO runs a query each day, how can you be assured necessary resources will be available when the query is run? (Select two.)

• A. Create a resource pool with dedicated resources for the CEO.
• B. Move all other users out of the general pool, leaving the CEO as the only user in the general pool.
• C. Reserve one core for use by the CEO user only.
• D. Assign the CEO user to the general resource pool with a high MEMORYCAP.
• E. Profile the query to determine estimated resource usage.

What is a benefit of having identically-sorted buddy projections?

• A. improved storage usage, since Vertica shares data files
• B. more efficient use of disk since the data is only on one node
• C. better query performance, since Vertica gets half the data from each projection
• D. fast recovery of a down node

Which statements are true about a prejoin projection? (Select three.)

• A. A prejoin projection enforces primary and foreign key constraints.
• B. A prejoin projection does not increase the storage footprint.
• D. A prejoin projection can process any type of join.
• E. A prejoin projection adds no limitations to the tables in the join.
• F. A prejoin projection improves query run time performance.

What is a difference between maxconcurrency and plannedconcurrency?

• A. Maxconcurrency is a hard limit to the number of queries running within a pool; plannedconcurrency is used to create a query budget.
• B. Maxconcurrency is used to create a query budget; plannedconcurrency is a hard limit to the number of queries running within a pool.
• C. Maxconcurrency is a hard limit to the number of queries running within a pool; plannedconcurrency limits the number of queries running on the cluster.
• D. Maxconcurrency limits the number of queries running on the cluster; plannedconcurrency is a hard limit to the number of queries running within a pool.

What are the advantages of a group by pipe versus a group by hash? (Select two.)

• A. A group by pipe uses memory more efficiently.
• B. A group by pipe can be processed spill to disk if the join result is large.
• C. A group by pipe is at least as fast as a group by hash.
• D. A group by pipe requires no optimization.
• E. A group by pipe builds its entire output table in memory.

What is local segmentation capability in Vertica?

• A. Vertica automatically splits current segments in half to redistribute them to new nodes.
• B. Vertica automatically partitions the data, allowing partitions to be dropped and recreated on new nodes.
• C. Vertica automatically creates more segments than are currently needed, allowing some segments to be moved to new nodes as needed.
• D. Vertica automatically partitions the segmented data, allowing some partitions to be moved to new nodes as needed.

Reference:http://vertica-forums.com/viewtopic.php?f=5&t=874

What is the process for online recovery of a failed node? (Select two.)

• A. The recovered node gathers the necessary files from nodes with its buddy projections.
• B. The recovered node verifies that it is current once a recovery cycle completes.
• C. The recovered node uses spread to speed up the recovery process.
• D. The recovered node restores all files from the last backup.
• E. The recovered node must be rebuilt from epoch 0.

What is a Vertica cluster?

• A. a collection of projection files
• B. a grouping of several Vertica databases
• C. the set of nodes running one instance of Vertica
• D. a physical machine configured to run an instance of Vertica

How can you disallow user connections, while preserving dbadmin connectivity?

• A. SELECT close_session (session_id);
• B. SELECT close_all_sessions;
• C. SELECT set_config_parameter ('MaxClientSessionsVS');
• D. SELECT set_config_parameter ('MaxClientSessionsVO');

What does Event Series Join do?

• A. enables analysis of two series of data when their measurement intervals do not align
• B. evaluates the values of a given set of variables and groups those values into a window
• C. enables identification of a sequence of defined events
• D. increments a counter based on whether an expression evaluates as true

50.pdf(page 1, see event series join)

Which statement is true about a query explain plan?

• A. It determines how to run the query, runs it, and returns the result.
• B. It writes the SQL to execute a query.
• C. It tells exactly how many rows will be returned by the query.
• D. It displays the results of Optimizer to the user, showing projection(s) used and the query process.

What can be used to determine memory resources needed by a query?

• A. Generate an EXPLAIN plan on the query.
• B. Review the digraph of the query.
• C. PROFILE the query.
• D. Run the query and view the information in the results.

Which features are available when using the Management Console for monitoring Vertica?
(Select two.)

• A. can only be accessed from a Windows machine
• B. can only be accessed from a Linux machine
• C. can be used by multiple users, with different sets of privileges for each
• D. provides a unified view of all Vertica clusters
• E. provides a visual depiction of CPU usage across the nodes of the cluster