Saturday, 30 July 2016

INDEX & MERGE

Index In Oracle 1.Its a Schema Object 2.Its One of the Performance tuning method. 3.It improves the performance of the query. 4.Index created by user and maintained by Database. Types Of Index:: 1.Unique Index 2.Non Unique Index 1.Unique Index:: It's crated by automatically by oracle,When...

SET OPERATORS

SET OPERATORS Set operators are used to join the results of two (or more) SELECT statements. TYPES:: 1.UNION 2.UNION ALL 3.INTERSECT 4.MINUS Condition to Use SET Operators:: 1.Number of Columns Should be same 2.Order By Should be Place at Last of the Query 3.The data types Should Be...

View In Oracle

View In Oracle Logical representation of subset of data is known as "View". Types Of View:: 1.Simple View         --->DML (INSERT,UPDATE,DELETE Possible) 2.Complex View --->DML (INSERT,UPDATE,DELETE Not Possible) Some Important Points about View::    ...

SQL*Loader

SQL*Loader In Oracle *Loading data's to table from the external File(Like CSV). *SQL*Loader is a bulk loader utility used for moving data from external files into the Oracle database.  STEPS:: ...

Sequence & Synonym

Sequence In Oracle **Its a Numeric Value Generator **Its Mostly used in Primary Key Columns **Its One of the Schema Object **Its a Sharable Object NEXTVAL:: The Oracle NEXTVAL function is used to retrieve the next value in a sequence. The Oracle NEXTVAL function must be called before calling...

Pseudocolumn

Pseudocolumn In Oracle A pseudocolumn behaves like a table column, but it's not actually stored in the table. TYPES:: 1.SYSDATE 2.SYSTIMESTAMP 3.USER 4.UID 5.ROWNUM 6.ROWID 7.NEXTVAL   --- Sequence Related Pseudo Columns 8.CURVAL --  Sequence...