Oracle Tutorials

Oracle Call Interface is a method of accesing database from a 3GL program. Uses--No
precompiler is required,PL/SQL blocks are executed like other DML statements. The OCI library provides
-functions to parse SQL statemets
-bind input variables
-bind output variables
-execute statements
-fetch the results
Difference between database triggers and form triggers ?
a) Data base trigger(DBT) fires when a DML operation is performed on a data base table.Form trigger(FT) Fires when user presses a key or navigates between fields on the screen b) Can be row level or statement level No distinction between row level and statement level.
c) Can manipulate data stored in Oracle tables via SQL Can manipulate data in Oracle tables as well as variables in forms. d) Can be fired from any session executing the triggering DML statements. Can be fired only from the form that define the trigger. e) Can cause other database triggers to fire.Can cause other database triggers to fire,but not other form triggers.
What is an UTL_FILE.What are different procedures and functions associated
with it ? UTL_FILE is a package that adds the ability to read and write to operating system files Procedures associated with it are FCLOSE, FCLOSE_ALL and 5 procedures to output data to a
file PUT, PUT_LINE, NEW_LINE, PUTF, FFLUSH.PUT, FFLUSH.PUT_LINE,FFLUSH.NEW_LINE. Functions associated with it are FOPEN, ISOPEN. Can you use a commit statement within a database trigger ?
No
What is maximum buffer size that can be specified using the DBMS_OUTPUT.ENABLE
function? 1,000,000
What is index ?
INDEX is a general term for an ORACLE / SQL feature used primarily to speed execution an
impose UNIQUENESS upon certain data. INDEX provides a faster access method to one table's
data than doing a full table scan.
There are several types of Indexes :
UNIQUE INDEX, COMPRESSED INDEX, CONCATENATED INDEX. An Index has an entry
for each value found in the table's Indexed field(s) ( except those with a NULL value ) and
pointer(s) to the rows having that value.

What is Data Dictionary ? The DATA DICTIONARY is a comprehensive set of tables and views owned by the DBA users SYS and SYSTEM, which activates when ORACLE is initially installed, and is a cental
source of information for the ORACLE RDBMS itself and for all users of ORACLE. The tables
are automatically maintained by ORACLE, and holds a set of views and tables containing
information about the database objects, users, privileges, events, and use.