1Z0-515 Online Practice Questions and Answers

Correct Answer: C

Explanation:

SYSDATE produces a new value every time it is used. Caching such a value would make no sense.

Correct Answer: D

Explanation:

There is no practical limit to number of cells that can be in the grid.

References:

Correct Answer: A

Explanation: Oracle OLAP is a world class multidimensional analytic engine embedded in Oracle Database 11g. Oracle OLAP cubes deliver sophisticated calculations using simple SQL queries - producing results with speed of thought response times. This outstanding query performance may be leveraged transparently when deploying OLAP cubes as materialized views enhancing the performance of summary queries against detail relational tables. Because Oracle OLAP is embedded in Oracle Database 11g, it allows centralized management of data and business rules in a secure, scalable and enterprise-ready platform.

Correct Answer: A

Explanation: The RESULT_CACHE_MODE initialization parameter determines the SQL query result cache mode. The parameter specifies when a ResultCache operator is spliced into a query's execution plan. The parameter accepts the following values: FORCE The ResultCache operator is added to the root of all SELECT statements, if that is possible. However, if the statement contains a NO_RESULT_CACHE hint, then the hint takes precedence over the parameter setting. MANUAL The ResultCache operator is added, only if you use the RESULT_CACHE hint in the SQL query.

References:

Correct Answer: A

Explanation:

Table storage requirements would increase, but the benefits are huge.

Oracle partitioning is a divide-and-conquer approach to improving Oracle maintenance and SQL performance. Anyone with un-partitioned databases over 500 gigabytes is courting disaster. Databases become unmanageable, and serious problems occur:

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SQL may perform poorly - Without Oracle partitioning, SQL queries with full-table scans take hours to complete. In a full scan, the smaller the Oracle partition, the faster the performance. Also, index range scans become inefficient.

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Recovery - Files recovery takes days, not minutes

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Maintenance - Rebuilding indexes (important to re-claim space and improve performance)

Oracle partitioning has many benefits to improve performance and manageability:

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Stable

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Robust

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Faster backups

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Less overhead

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Easier management Maintenance of Oracle partitioned tables is improved because maintenance can be focused on particular portions of tables. For maintenance operations across an entire database object, it is possible to perform these operations on a per-partition basis, thus dividing the maintenance process into more manageable chunks. (not D)

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Faster SQL Oracle is partition-aware, and some SQL may improve is speed by several orders of magnitude (over 100x faster).

-Index range scans Oracle partitioning physically sequences rows in index-order causing a dramatic improvement (over 10x faster) in the speed of partition-key scans.

-Full-table scans Oracle partition pruning only accesses those data blocks required by the query.

-Table joins Oracle partition-wise joins take the specific sub-set of the query partitions, causing huge speed improvements on nested loop and hash joins. (not C)

-You can also improve the performance of massive join operations when large amounts of data (for example, several million rows) are joined together by using partition-wise joins. (not B)

-Updates Oracle parallel query for partitions improves batch load speed.

References:

Correct Answer: B

Explanation:

The database automatically invalidates a cached result whenever a transaction modifies the data or

metadata of any of the database objects used to construct that cached result.

Note: DML is abbreviation of Data Manipulation Language. It is used to retrieve, store, modify, delete,

insert and update data in database. References:

Correct Answer: A

Explanation: If your priority is manageability, use a local index. Local partitioned indexes are easier to manage than other types of partitioned indexes. They also offer greater availability and are common in DSS environments. The reason for this is equipartitioning: each partition of a local index is associated with exactly one partition of the table. This enables Oracle to automatically keep the index partitions in sync with the table partitions, and makes each table-index pair independent. Any actions that make one partition's data invalid or unavailable only affect a single partition.

Local partitioned indexes support more availability when there are partition or subpartition maintenance operations on the table. A type of index called a local nonprefixed index is very useful for historical databases. In this type of index, the partitioning is not on the left prefix of the index columns. References:

Correct Answer: C

Explanation: Oracle Advanced Security is an option to the Oracle Database 11g Enterprise Edition that helps address privacy and regulatory requirements including the Payment Card Industry Data Security Standard (PCIDSS), Health Insurance Portability and Accountability Act (HIPAA), and numerous breach notification laws. Oracle Advanced Security provides data encryption and strong authentication services to the Oracle database, safeguarding sensitive data against unauthorized access from the network and the operating system. It also protects against theft, loss, and improper decommissioning of storage media and database backups.

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Correct Answer: A

Explanation: Data Mining and Data Warehousing Data can be mined whether it is stored in flat files, spreadsheets, database tables, or some other storage format. The important criteria for the data is not the storage format, but its applicability to the problem to be solved. Proper data cleansing and preparation are very important for data mining, and a data warehouse can facilitate these activities. However, a data warehouse will be of no use if it does not contain the data you need to solve your problem. Oracle Data Mining requires that the data be presented as a case table in single-record case format. All the data for each record (case) must be contained within a row. Most typically, the case table is a view that presents the data in the required format for mining Note: Oracle Warehouse Builder (OWB) enables the design and deployment of enterprise data warehouses, data marts, and e-business intelligence applications.

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Correct Answer: D

Explanation: