Fundamental Object-Oriented Concepts

  • In Java, a narrowing conversion is also known as an explicit type conversion or casting.
  • A byte can represent values between -128 to 127.
  • An array, in Java, is an ordered collection of primitives, object references, or other arrays. All the elements of an array must be of the same type, except in case of polymorphism.
  • Array elements are initialized to default values, wherever they are created.
  • The increment operator can be used in either of the two forms given below:
    1. Prefix form: In the prefix form, it appears before the operand. For example, ++a;
    2. Postfix form: In the postfix form, it appears after the operand. For example, a ++;
  • Numeric promotions are used to convert the operands in a numeric expression to a common type before an operation is performed between the operands.
  • In Java, there are two kinds of numeric promotions as follows:
    1. Unary numeric promotion
    2. Binary numeric promotion
  • Pass SCJA Certification Java 1.2 in a first attempt:

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    List the capabilities of SQL SELECT statements

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    Posted in OCA.

    uCertify (May 27, 2009) uCertify, a leading IT certifications solutions provider, has recently launched its new simulation software for the 1Z0-051 certification exam. Keeping in mind that time and money are your most valuable resources, uCertify has come up with the best and most innovative study material for the 1Z0-051 certification exam. To get a glimpse of the 1Z0-051 PrepKit, you can download its free demo version (which contains 15 free practice questions) from:

    http://www.ucertify.com/exams/Oracle/1Z0-051.html.

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    Posted in OCA.

    Robert G. Freeman is a Principal Engineer and Database Team Manager at the Church of Jesus Christ of Latter-Day Saints in Salt Lake City, UT, USA. He has been working with Oracle Databases for almost two decades. Robert is the author of several books including Oracle Database 10g RMAN Backup and Recovery and Oracle Database 11g New Features. Robert is an Oracle ACE, and is currently the only residing ACE in the state of Utah, USA. When not working with Oracle databases Robert may be found flying around in his airplane, kicking in karate class or just hanging out with his wife, kids, 2 cats and a dog named Denali.

    Robert is a co-author for following uCertify PrepKit:
    1Z0-051: OCA: Oracle Database 11g-SQL Fundamentals-I
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    Deepak Jaisingh has 10+ years of technical experience in various industries like Banking, Manufacturing, Insurance etc. His expertise lie in Database and System Administration. His “Never Give Up” attitude is the reason behind all his success. He started his career in a small call center, then very soon he migrated to IT and from there on he never looked back. Oracle became his passion and his job, his obsession.

    Deepak is an Oracle certified professional (OCP) and Sun Certified Java Professional (SCJP). He is currently perusing OCM.

    Deepak is co-author and contributor for following PrepKits:
    1Z0-042: Oracle 10g DBA Admin I
    1Z0-043: Oracle 10g DBA Admin I,
    1Z0-047: Oracle 11g SQL Expert

    Bob Bryla is an Oracle 8, 8i, 9, 10g and 11g Certified Professional with more than 20 years of experience in database design, database application development, training, and Oracle database administration. He is the primary internet database designer and developer at Lands’ End in Dodgeville, Wisconsin. Bob works with PL/SQL and Oracle on a daily basis to support the back end of the world’s #1 clothing web site, landsend.com.

    Bob Bryla Co-Author and contributor for following uCertify PrepKit
    1Z0-052 OCA: Oracle Database 11g: Administration I

     

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    General high availability technologies in 10g

    • The ORDER BY clause sorts the records in ascending order and it comes last in the SELECT statement.
    • The Online redo log files and the operating system flat file are used to store a copy of a data dictionary.
    • RMAN can be used to take an incremental backup for tablespaces and data files.
    • The rman target/ command is used to maintain backup copies by connecting to the target database and returns the RMAN prompt to issue further backup commands.
    • The NLS_LANG parameter must be set to specify the language, territory, and character set used in an application.
    • CONFIGURE is an RMAN command that configures an RMAN environment.
    • CONFIGURE RETENTION POLICY CLEAR is a command that will configure the retention policy to the default of REDUNDANCY 1.
    • RMAN is used to migrate the database files from conventional file system storage to ASM storage.
    • The control file, target database catalog, and Recovery catalog are used to store the RMAN’s persistent settings.
    • The redo files are opened after executing the ALTER DATABASE OPEN command on a database when it is in MOUNT mode.
    • RMAN can be used to move database objects from a non-ASM disk location to an ASM disk group.
    • The V dynamic performance view includes the status, the location where the block change tracking file is stored, and the size in bytes of the file.
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    Oracle architecture

    • The size of the shared pool can be changed dynamically. The data dictionary cache of the shared pool holds the most recently accessed data dictionary information. The shared pool consists of a library cache and data dictionary cache.
    • Control file, redo log file, and data file are part of an Oracle database.
    • An SGA and Oracle background processes constitute an Oracle instance. An SGA is ended when an Oracle instance is shut down. Multiple users can share data in an SGA.
    • While making modifications in SPFILE, the instance should be in open and running state, whereas in the case of PFILE, the instance will have to be first shut down and restarted before making any modifications in it.
    • V is a dynamic performance view that is used to display the names and the location of all the control files.
    • Following is the correct sequence of the processes that occur when a database is opened:
      1. An initialization parameter file is read.
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    New Features of Oracle 10g, Oracle 10g Installation, Server Configuration, and Maintenance of the Software

    • Memory – 512MB, Temp space – 400MB of free space in the /tmp directory applicable for the Unix operating system, Swap space – 1GB or twice the amount of RAM, Free disk space – 1.5GB are the minimum hardware requirements to install Oracle 10g.
    • The Installation Type list box is used to decide the type of installation.
    • Oracle Management Agent (OMA) is a centralized administrative tool that is capable of administering the database server and an application server.
    • The location (/u01/app/oracle) will be considered as the base of Optimal Flexible Architecture (OFA).
    • The password file is used to authenticate the administrative tasks from remote locations.
    • An Oracle 10g client can be used to connect to an Oracle 8i or 9i database by using the following syntax:
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    Q. What is the pre-requisite for taking the 1z0-042 test?

    A. There is no prerequisite for the 1z0-042 test. The 1z0-042 (OCA) is the first step in the Oracle Database 10g certification track and also the first step towards a successful career as an Oracle professional. However, you must be well experienced with the SQL before you take the test. Even if you are new to the Oracle field, you can still pass the test with self-study or self-schooling. This will require a lot of dedication and practice, managing a database and newly added features in 10g.

    Q. How can I register for the test?

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