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_ for SINGLE CHARACTER SUBSTITUTION and % for multi-character substitution.

_ for single character substitution and % for multi-character substitution.

&.

&.

TRUNCATE commits after deleting ENTIRE table i.e., cannot be rolled back. Database triggers do not FIRE on TRUNCATE.
DELETE ALLOWS the FILTERED deletion. Deleted RECORDS can be rolled back or committed. Database triggers fire on DELETE.

TRUNCATE commits after deleting entire table i.e., cannot be rolled back. Database triggers do not fire on TRUNCATE.
DELETE allows the filtered deletion. Deleted records can be rolled back or committed. Database triggers fire on DELETE.

SQL Injection is when form DATA CONTAINS an SQL escape sequence and injects a new SQL query to be RUN.

SQL Injection is when form data contains an SQL escape sequence and injects a new SQL query to be run.

Join is a query, which RETRIEVES RELATED columns or rows from multiple tables.
Self Join - JOINING the table with itself.
Equi Join - Joining two tables by equating two common columns.
Non-Equi Join - Joining two tables by equating two common columns.
Outer Join - Joining two tables in such a way that query can ALSO RETRIEVE rows that do not have corresponding join value in the other table.

Join is a query, which retrieves related columns or rows from multiple tables.
Self Join - Joining the table with itself.
Equi Join - Joining two tables by equating two common columns.
Non-Equi Join - Joining two tables by equating two common columns.
Outer Join - Joining two tables in such a way that query can also retrieve rows that do not have corresponding join value in the other table.

Sub-QUERY is a query WHOSE RETURN values are used in FILTERING conditions of the main query.

Sub-query is a query whose return values are used in filtering conditions of the main query.

CORRELATED sub-QUERY is a sub-query, which has REFERENCE to the MAIN query.

Correlated sub-query is a sub-query, which has reference to the main query.

RETRIEVES ROWS in hierarchical ORDER eg.
select empno, ename from emp where.

Retrieves rows in hierarchical order eg.
select empno, ename from emp where.

INTERSECT - returns all distinct ROWS selected by both QUERIES.
MINUS - returns all distinct rows selected by the FIRST query but not by the second.
UNION - returns all distinct rows selected by either query
UNION ALL - returns all rows selected by either query, including all duplicates.

INTERSECT - returns all distinct rows selected by both queries.
MINUS - returns all distinct rows selected by the first query but not by the second.
UNION - returns all distinct rows selected by either query
UNION ALL - returns all rows selected by either query, including all duplicates.

ROWID is a PSEUDO COLUMN attached to each row of a table. It is 18 CHARACTERS LONG, blockno, ROWNUMBER are the components of ROWID.

ROWID is a pseudo column attached to each row of a table. It is 18 characters long, blockno, rownumber are the components of ROWID.

USING ROWID.
CONSTRAINTS.

Using ROWID.
CONSTRAINTS.

INTEGRITY CONSTRAINT is a RULE that RESTRICTS VALUES to a column in a table.

Integrity constraint is a rule that restricts values to a column in a table.

Maintaining DATA integrity through a SET of rules that restrict the values of one or more columns of the tables BASED on the values of PRIMARY KEY or unique key of the referenced table.

Maintaining data integrity through a set of rules that restrict the values of one or more columns of the tables based on the values of primary key or unique key of the referenced table.

SAVEPOINTS are used to subdivide a transaction into SMALLER PARTS. It enables rolling BACK PART of a transaction. Maximum of five save points are allowed.

SAVEPOINTS are used to subdivide a transaction into smaller parts. It enables rolling back part of a transaction. Maximum of five save points are allowed.

When ON DELETE CASCADE is specified Oracle maintains REFERENTIAL integrity by AUTOMATICALLY removing dependent foreign KEY values if a referenced PRIMARY or unique key value is removed.

When ON DELETE CASCADE is specified Oracle maintains referential integrity by automatically removing dependent foreign key values if a referenced primary or unique key value is removed.

CHAR, VARCHAR2, NUMBER, DATE, RAW, LONG and LONG RAW.

CHAR, VARCHAR2, NUMBER, DATE, RAW, LONG and LONG RAW.

CHAR PADS BLANK spaces to the maximum length.
VARCHAR2 does not PAD blank spaces.
For CHAR the maximum length is 255 and 2000 for VARCHAR2.

CHAR pads blank spaces to the maximum length.
VARCHAR2 does not pad blank spaces.
For CHAR the maximum length is 255 and 2000 for VARCHAR2.

Only ONE LONG COLUMN is allowed. It is not POSSIBLE to USE LONG column in WHERE or ORDER BY clause.

Only one LONG column is allowed. It is not possible to use LONG column in WHERE or ORDER BY clause.

• To MODIFY the datatype of a COLUMN the column MUST be empty.
• To ADD a column with NOT NULL constrain, the table must be empty.

The INTEGRITY CONSTRAINTS are STORED in USER_CONSTRAINTS.

The integrity constraints are stored in USER_CONSTRAINTS.

The INTEGRITY CONSTRAINTS can be enabled or disabled by ALTER TABLE ENABLE CONSTRAINT /
DISABLE CONSTRAINT.

The integrity constraints can be enabled or disabled by ALTER TABLE ENABLE CONSTRAINT /
DISABLE CONSTRAINT.

It won't, Because SYSDATE format CONTAINS TIME attached with it.

It won't, Because SYSDATE format contains time attached with it.

DATABASE LINK is a named PATH through which a REMOTE database can be accessed.

Database link is a named path through which a remote database can be accessed.

CYCLE specifies that the sequence continue to generate values after REACHING EITHER MAXIMUM or MINIMUM value. After pan-ascending sequence reaches its maximum value, it generates its minimum value. After a descending sequence reaches its minimum, it generates its maximum.

NO CYCLE specifies that the sequence cannot generate more values after reaching its maximum or minimum value.

CYCLE specifies that the sequence continue to generate values after reaching either maximum or minimum value. After pan-ascending sequence reaches its maximum value, it generates its minimum value. After a descending sequence reaches its minimum, it generates its maximum.

NO CYCLE specifies that the sequence cannot generate more values after reaching its maximum or minimum value.

• To PROTECT some of the columns of a table from other users.
• To hide complexity of a QUERY.
• To hide complexity of calculations.

1. CURSOR action_cursor,
2. SELECT NAME, RATE, ACTION,
3. into action_record,
4. from action_table.

1. STATEMENT and ROW,
2. Statement only,
3. Row only,
4. ORACLE FORMS TRIGGER.

1.  RAISE_ERROR,
2. SQLERRM,
3.  RAISE_APPLICATION_ERROR,
4.  RAISE_SERVER_ERROR.

1. ALTER TRIGGER check_theater ENABLE;
2. ENABLE TRIGGER check_theater;
3. ALTER TABLE check_theater ENABLE check_theater;
4. ENABLE check_theater;

1.  ALTERING the argument list of ONE of the PACKAGE constructs, 
2. Any change made to one of the package constructs, 
3. Any SQL statement change made to one of the package constructs,
4. Removing a local variable from the DECLARE section of one of the package constructs.

1. When the transaction is COMMITTED,
2.  During the data manipulation statement,
3. When an Oracle SUPPLIED PACKAGE references the TRIGGER,
4. During a data manipulation statement and when the transaction is committed.

Preemptive REFERS to the fact that each TASK is alloted fixed time SLOTS and at the END of that time slot the next task is started.

Preemptive refers to the fact that each task is alloted fixed time slots and at the end of that time slot the next task is started.

OLTP STANDS for On LINE TRANSACTION PROCESSING.

OLTP stands for On Line Transaction Processing.

OLTP REQUIRES REAL TIME RESPONSE.

OLTP requires real time response.

The client deals with the USER interface PART of the SYSTEM.

The client deals with the user interface part of the system.

To reduce the NETWORK TRAFFIC and for APPLICATION SHARING and IMPLEMENTING business rules.

To reduce the network traffic and for application sharing and implementing business rules.

APPLICATIONS that have OUTGROWN their ENVIRONMENT are re-engineered to RUN in a LARGER environment. This is upsizing.

Applications that have outgrown their environment are re-engineered to run in a larger environment. This is upsizing.

With RIGHTSIZING, ONE would move APPLICATIONS to the most appropriate server PLATFORMS.

With rightsizing, one would move applications to the most appropriate server platforms.

A HOST based application is re-engineered to run in SMALLER or LAN based ENVIRONMENT.

A host based application is re-engineered to run in smaller or LAN based environment.

An EVENT TRIGGER, a segment of code which is associated with each event and is fired when the event OCCURS.

An event trigger, a segment of code which is associated with each event and is fired when the event occurs.

When a stored procedure is called, only the procedure CALL is SENT to the SERVER and not the statements that the procedure contains.

When a stored procedure is called, only the procedure call is sent to the server and not the statements that the procedure contains.

• FOREGROUND PROCESS and,
• BACKGROUND process.

An EVENT handler is a ROUTINE that is WRITTEN to respond to a PARTICULAR event.

An event handler is a routine that is written to respond to a particular event.

An integrity CONSTRAINT ALLOWS the DEFINITION of certain restrictions, at the table LEVEL, on the data that is entered into a table.

An integrity constraint allows the definition of certain restrictions, at the table level, on the data that is entered into a table.

Database TRIGGERS can be used to enforce BUSINESS RULES, to MAINTAIN derived VALUES and perform value-based auditing.

Database triggers can be used to enforce business rules, to maintain derived values and perform value-based auditing.

A transaction is a set of OPERATIONS that begin when the first DML is ISSUED and end when a COMMIT or ROLLBACK is issued. BEGIN COMMIT/ROLLBACK are the boundaries of a transaction.

A transaction is a set of operations that begin when the first DML is issued and end when a commit or rollback is issued. BEGIN COMMIT/ROLLBACK are the boundaries of a transaction.

Because it is easier to define an INTEGRITY CONSTRAINT than a database TRIGGER.

Because it is easier to define an integrity constraint than a database trigger.

Because an INTEGRITY constraint is AUTOMATICALLY checked while data is INSERTED into a table. A stored has to be specifically invoked.

Because an integrity constraint is automatically checked while data is inserted into a table. A stored has to be specifically invoked.

• A CLIENT,
• A SERVER and
• A Network/Communication SOFTWARE.

Flexibility of the system, scalability, COST saving, CENTRALISED CONTROL and implementation of business rules, increase of developers productivity, portability, improved NETWORK and resource utilization.

Flexibility of the system, scalability, cost saving, centralised control and implementation of business rules, increase of developers productivity, portability, improved network and resource utilization.