1. Identifying tuning areas through querying the available views.
2. Gathering statistics through available tools, such as STATSPACK.
3. Using the available GUI tools, such as Instance Manager to resolve contentions.
4. Changing the values of various initialization parameters to monitor the subsequent affect on the system performance.
5. Changing the size of various database objects, such as buffers, pools, tablespace, and rollback segments to monitor its affect on the performance of the system.

Pass OCP DBA 9i certification exam in first attempt. Download latest exam simulation, questions, tutorial and study guide for OCP DBA 9i:

Pass one of the following entry level exams:
• 1Z0-007 Introduction to Oracle9i: SQL
• 1Z0-047 Oracle Database SQL Expert
• 1Z0-051 OCA: Oracle Database 11g-SQL
Pass all of the following core exams:
• 1Z0-031 Oracle9i Database: Fundamentals I
• 1Z0-032 Oracle9i Database: Fundamentals II
• 1Z0-033 Oracle9i DB: Performance Tuning
• Performing administrative tasks, such as setting frequency of checkpoints to monitor the affect on the system performance.
• Identifying and resolving locking contentions by using the available views and GUI tools.
• Configuring various processes in the shared server architecture, such as, Oracle Net listener and the dispatcher.
• Configuring block parameters, such as PCTFREE and PCTUSED for enhanced performance.
• Configuring materialized views through the initialization parameters for optimal performance.
• Employing different types of indexes for storage purposes and monitoring the performance in each case through the available views.

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Pass OCA DBA 9i certification exam in first attempt. Download latest exam simulation, questions, tutorial and study guide for OCA DBA 9i:

Pass one of the following entry level exams:
• 1Z0-007 Introduction to Oracle9i: SQL
• 1Z0-047 Oracle Database SQL Expert
• 1Z0-051 OCA: Oracle Database 11g-SQL Fundamentals-I

Pass the following core exam:
• 1Z0-031 Oracle9i Database: Fundamentals I

1. Install and uninstall Oracle by using Oracle Universal Installer (OUI).
2. Create a password file and set up password file authentication for administrative users.
3. Create an initialization parameter file.
4. Start up and shut down an Oracle instance.
5. Create a database by using the Database Configuration Assistant (DBCA).
6. Create a database manually.
7. Multiplex control files and online redo log files.
8. Create locally-managed and dictionary managed permanent and temporary tablespaces.
9. Change the size of a permanent tablespace by adding data files to it.
10. Implement automatic undo management by creating an undo tablespace.
11. Create, alter, reorganize, truncate, and drop a table.
12. Create, reorganize, and drop various types of indexes.
13. Create various types of constraints and enable and disable constraint checking.
14. Create, alter, and drop database users.
15. Create and remove roles and profiles.
16. Grant and revoke privileges from database users and roles.
17. Use different types of National Language Support (NLS) parameters.

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OCA DBA 9i is an entrance level certification that builds the foundation of a Database Administrator or a Database Application Developer. The foundational concepts include the basics of RDBMS, basics of writing a SQL Query, and using Oracle tools. Its objectives are intended to validate a candidate’s skill of implementing and managing complex Oracle database functions. It is an essential certification for the advanced certification level (OCP DBA 9i).

Core tests of OCA DBA 9i

To gain OCA DBA 9i, any one of the following tests can be taken:

• 1z0-001: Introduction to Oracle PL/SQL
• 1z0-007: Introduction to Oracle 9i SQL
• 1z0-031: Oracle 9i Fundamental I

What is the 1z0-001 test?

The 1z0-001 test validates your knowledge as an Oracle Application Developer and PL/SQL script writer. The test helps you gain OCA DBA 9i and also is a prerequisite for OCP DBA 9i. Following are some of the key areas for the 1z0-001 test:

• Concepts of RDBMS
• PL/SQL scripts
• SQL query

What is the 1z0-007 test?

The 1z0-007 test validates your capability to develop an Oracle Application on 9i platform. The test is an elective one; either you give 1z0-001 or 1z0-007, you will gain the OCA DBA 9i certification.

Following are some key areas for the 1z0-007 test:

• SQL query
• Manage table using SQL statement
• Know database objects

What is the 1z0-031 test?

The 1z0-031 test validates your knowledge on Oracle 9i fundamentals. It is a core test for OCA DBA 9i.

Following are some key areas for 1z0-031 test:

• Oracle tools
• Manage control and redo log files
• Manage users and roles

Benefits of OCA DBA 9i

The demand of Oracle professionals is growing incredibly. Therefore, OCA DBA 9i proves your expertise in administrating a database on 9i platform. Earning the certificate of OCA DBA proves that the candidate is professionally serious.

By earning the OCA level credential, one increases the chance of entry level job opportunities in reputed organizations. Certifying yourself gives you a proven level of knowledge and expertise. Having an OCP certification, you can earn a respectable amount as compared to what other DBA developer professionals are earning, the reason being that OCP certified professionals have a direct impact on the growth of the company. Following are few benefits of being OCP:

• It adds value to your Oracle career.
• It increases job opportunities.
• It adds value to your resume.
• It helps you to avail discounts and offers on Oracle press books.

Job roles of OCA DBA 9i

OCA DBA 9i certification prepares you for a competitive Oracle career ahead by giving you enough knowledgebase. Oracle certifications provide a positive direction to your Oracle career. The job roles for OCA DBA 9i certified professionals are listed below:

• Database Administrator
• Database Analyst
• Database Developer

How uCertify helps you get OCA DBA 9i?

uCertify provides quality practice software to qualify OCA DBA 9i (1z0-001, 1z0-007, 1z0-031) certification. The preparation kit prepares a candidate for the real test environment. The practice questions include analysis of the correct answer along with incorrect answer options too. uCertify also provides study notes that will help to understand the key concepts that are included in the test. The practice test also includes full length articles, interactive quizzes, tips, and how to’s that will provide enough insight to learn for the certification. You can also create your own test based on your strength and weaknesses. Therefore, uCertify is the ultimate resource to gain OCP DBA 10g certificate. Lastly, uCertify’s Prepkit allows you to easily learn and earn the certification.
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• The numeric data type is represented as NUMBER
• The WHERE clause in the SELECT statement does not support a group function.
• Single ampersand (&) and double ampersand (&&) are the types of substitution variables.
• Projection is a capability used to choose the columns that a user wants to retrieve from a table by using a SELECT statement.
• The concatenation operator (||) is used to combine the column values.
• The ALL operator is used in the WHERE clause and it compares a value with any of the values in the list provided.
• The column list can be omitted from the INSERT INTO command, but the values must match the order of the columns as listed in the output from the DESC(RIBE) command.

Pass OCA Certification DBA 11g Certification Exam in a first attempt.

• Download free Practice test and Study Notes for 1Zo-051- OCA: Oracle Database 11g-SQL Fundamentals-1
• Download free Practice test and Study Notes for 1Z0-052- OCA: Oracle Database 11g:Administration-1

Apply conditional expressions in a SELECT statement
• The CASE expression is preferred over DECODE().
• IS NULL is a comparison operator that is used to compare a value with a NULL value. It evaluates to TRUE if the value is NULL, otherwise it evaluates to FALSE.
• The AS keyword is used to define a column alias, and double quotes are used when an alias consists of multiple words or its case is important.
• The result of any arithmetic operation between two date values represents a certain number of days.

Limit and sort the rows that are retrieved by a query

• In positional sorting, only those columns that are specified in the SELECT list can be appended to the ORDER BY clause.
• The NOT operator negates conditional operators.
• Oracle performs an implicit data type conversion as and when required.
• Character literal data is always case sensitive and must be enclosed within single quotes.
• The syntax of using the DISTINCT clause is SELECT DISTINCT columnname1, columnname2,.. FROM tablename;.
• The BETWEEN operator is used to retrieve a range of data between two values.
• The ORDER BY clause is used to sort the data in either ascending or descending order.
• In Oracle, the character searches are case sensitive.
• The ROWNUM pseudocolumn is used to avoid a massive sort of large result sets.
• The <> and != operators are the not equal operators in Oracle.

Use ampersand substitution to restrict and sort output at runtime

• The ampersand substitution variable must be enclosed in single quotes when dealing with the character and date values.
• The SET DEFINE command is used to specify a variable character other than an ampersand (&).
• Substitution variables such as & and && are used to temporarily store values.
• Notepad is used to edit an earlier issued SQL statement in SQL*Plus.

Describe various types of functions available in SQL

• The ROUND function is used to round numeric values in a column or numbers to n decimal places right of the decimal point.
• A forward slash, a semicolon, and RUN command are used to execute a SQL statement or a PL/SQL block.
• DUAL is a dummy table that returns exactly one row, used especially in pseudo columns.
• The soundex function is used to get a string containing the phonetic representation of x.
• The Translate() function is used to convert occurrences of characters present in x from i sequence to j sequence.
• The MOD and REMAINDER functions are the same, but both use different functions in their formula.
• The NVL function is used when a non-NULL value needs to be returned in place of a NULL value.

Use character, number, and date functions in SELECT statements

• The CONCAT function must be nested to join three string literals.
• The concatenation operator (||) is capable of performing a complex task in a simpler manner.
• The SUBSTR function extracts a substring of a specified length from the source string. The start position after the source string specifies from where a substring is extracted.
• If the end date occurs before the start date, a negative number is returned in the MONTHS_BETWEEN function.
• A negative value specifies that the date value to be returned by the ADD_MONTHS function must be prior to the specified date.
• Using the TRUNC function to truncate a date to the year level will return the date to the beginning of the current year.
• The TRUNC function is used to truncate a number to n digits of precision.
• The NLS_TERRITORY parameter is used to specify the name of the territory. The date format is according to the name of the specified territory.
• The ROUND (number) function is used for rounding off values in a column or numbers to n decimal places.
• YEAR is a fmt that rounds up the date value on 1st July.

Describe various types of conversion functions that are available in SQL

• Oracle returns an “ORA-1722: invalid number” error while performing an implicit conversion for invalid character data representing an invalid number.
• Single arguments are not allowed in the NVL function. Therefore, Oracle will generate an ORA error.
• Oracle does not implicitly convert character literals to DATE data.
• The Translate() is used to convert numbers and strings. It can also accept a column value as an argument.
• The TO_CHAR function is used to convert data types explicitly.
• Oracle treats the number value given in single quotes as a string value.
• When the two date values are subtracted, it yields the number of days between the two dates.

Pass OCA Certification DBA 11g Certification Exam in a first attempt.

• Download free Practice test and Study Notes for 1Zo-051- OCA: Oracle Database 11g-SQL Fundamentals-1
• Download free Practice test and Study Notes for 1Z0-052- OCA: Oracle Database 11g:Administration-1

Describe group functions

• Group functions can only be nested two levels deep.
• Rows with null values occurring in group columns or expressions are ignored.
• No aggregate function can be used with the WHERE clause.

Group data by using the GROUP BY clause

• Group data by using the GROUP BY clause.
• Some of the rules that decide the usage of group functions are as follows:
  1. If an item that is not a group function appears in the SELECT list and there is no GROUP BY clause, an “ORA-00937: not a single-group group function” error is raised.
  2. If a GROUP BY clause is present, but the item present in the GROUP BY clause is not a grouping attribute, an “ORA-00979: not a GROUP BY expression” error is raised.
  3. If a group function is placed in a WHERE clause, an “ORA-00934: group function is not allowed here” error is raised.
• A single-row function can be nested within group functions.

Include or exclude grouped rows by using the HAVING clause

• Any column or expression that is in the SELECT list is not an aggregate function.
• When any group function is used in a query, the WHERE clause is not used to restrict the rows, rather the HAVING clause is used.
• MAX is an aggregate function that returns maximum value in a group.

Write SELECT statements to access data from more than one table using equijoins and nonequijoins

• Equi join is also known as inner join or simple join.
• Inner join produces only the matching rows from the joining tables.

Join a table to itself by using a self-join

• The full outer join can also retrieve all unmatched data from two tables.

View data that generally does not meet a join condition by using outer joins

• To join n tables, n-1 join conditions are required.
• Some of the limitations of an outer join are given below:
  1. The outer join operator can be placed only on one of the joins.
  2. The outer join operator cannot be used with the IN operator.
  3. The outer join operator cannot be used with any other join operator that uses the OR operator.
• Different table aliases for the same table is used to perform a self join.

Generate a Cartesian product of all rows from two or more tables

• A Cartesian product is a set of all possible combination of rows drawn from each table involved in the join.

Write single-row and multiple-row subqueries

• Two classes of comparison conditions are used in subqueries: single-row operators and multiple-row operators.
• If an inner query returns a NULL, the subquery returns no rows.

Describe set operators

• (unary), – (unary), *, /, ||, =, !=, <, >, <=, >=, IS NULL, LIKE, BETWEEN, IN, NOT, AND, OR is the correct order of operators precedence.

Control transactions

• The ROLLBACK command is used to end the current transaction, and to discard any changes made since the beginning of the transaction.
• If a query returns one row, an implicit cursor is automatically executed.
• An existing column cannot be renamed.
• ACID stands for Atomic, Consistent, Isolated, Durable.
• The COMMIT and ROLLBACK commands are used to terminate a transaction.
• Two savepoints with a common name cannot exist.
• Oracle does not allow to insert a row with a primary key value that already exists in a table.

Categorize the main database objects

• VALUE() can be used to retrieve rows from an object table.
• Primary key is used to enforce row integrity in a table.
• Data files are system files.
• A sequence is used to generate the Primary key value for a database.
• The last_number column displays the next available sequence number if NOCACHE is specified.
• The USER_SEQUENCES data dictionary view is used to verify the values of a sequence.

Review the table structure

• Once a table alias is defined for a table, the columns of the table can be qualified with the table alias only.
• The DESC command is used to describe the schema of a table.
• The DESC(RIBE) command is used to describe an Oracle table.
• The DESC(RIBE) command is used to describe a table.

List the data types that are available for columns

• User defined exception messages are written in the declarative section of a Pl/SQL block.
• String values and date values must be enclosed in single quotes.
• The VARCHAR2 data type trims the insignificant spaces of a string value.

Explain how constraints are created at the time of table creation

• Columns can be defined either at the column or the table level.
• Oracle server generates the name of a constraint with SYS_Cn format when the name has not been defined by a database user. The constraints and all the related information are stored in the USER_CONSTRAINTS data dictionary view.
• The USER_CONSTRAINTS data dictionary is used to store all constraint-related information of any current user.

Create simple and complex views, private and public synonyms, indexes, sequences

• The CREATE TABLE does not immediately end with a semicolon, and a column name cannot start with a numeric value. However, a numeric value can be used in between a column name.
• A tablename cannot start with the @ special character.
• A view is a virtual table that helps to manage permissions and other administrative tasks on a table.
• Oracle Server retrieves the view definition from the USER_VIEWS data dictionary view, checks all access privileges for the base table, and also runs the view query on the base table.
• The OR REPLACE clause is used to modify a view without dropping, recreating, and regranting the object privileges on a view.

Retrieve data from views

• The GRANT CREATE VIEW TO user_name; statement is used to grant the CREATE VIEW privilege to a database user.
• The CREATE VIEW and CREATE ANY VIEW system privileges must be granted to create a view in user’s own schema.

Pass OCA Certification DBA 11g Certification Exam in a first attempt.

• Download free Practice test and Study Notes for 1Zo-051- OCA: Oracle Database 11g-SQL Fundamentals-1
• Download free Practice test and Study Notes for 1Z0-052- OCA: Oracle Database 11g:Administration-1

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