tag:blogger.com,1999:blog-11014819050862929422012-01-16T23:31:20.648-08:00This is the perfect blog for all Oracle Developers. visit our site : www.oraclepassport.com for best available Oracle Interview Questions. Lots and Lots of Oracle interview questions, www.oraclepassport.com, Oracle Questions, PL/SQL Cursors, Triggers - row level,Oracle Interview questions with answers, pl/sql interview, tables, cursors, triggers, stored procedures, indexes,views, oracle tutorial, oracle questions and answerssippsinnoreply@blogger.comBlogger21100tag:blogger.com,1999:blog-1101481905086292942.post-17059025568565186702009-02-27T07:10:00.000-08:002009-02-27T07:20:10.005-08:00<a href="http://www.oraclepassport.com" target="_blank"><br /><font color=red size=3 face="times">Visit OraclePassport Main Page</font></a><br /><br /> The PL/SQL has two different methods for passing parameter values between stored procedures and functions, <br /><br />1. Pass by value<br /> Actual value is being copied to another memory location for the calling procedure/function to use<br /> i.e it copies the actual value of the parameter into the formal parameter. So, both called and calling procedures has got 2 different memory locations to store the value<br /><br /><br /><br />2. Pass by reference<br /><br />Only the memory location (address) is passed so that the data is not copied. The calling procedure and the called procedure, both uses the same value stored in a single memory location. So the actual and the formal parameters refer to the same memory location that holds the value. <br /><br />As we know, there are three different type of parameters in PL/SQL:<a href="http://www.oraclepassport.com" target="_blank"><br /><font color=red size=3 face="times">Read More....</font></a><br><br><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/1101481905086292942-1705902556856518670?l=itcompreview.blogspot.com' alt='' /></div>sippsinnoreply@blogger.com0tag:blogger.com,1999:blog-1101481905086292942.post-81619708265725242522009-02-27T07:01:00.000-08:002009-04-19T10:32:47.083-07:00<a href="http://www.oraclepassport.com" target="_blank"><br /><font color=red size=3 face="times">Visit OraclePassport Main Page</font></a><br /><br /> A materialized view is a snapshot of data which could be refreshed at defined intervals. From the name, it is unclear that a materialized view can hold data, since views dont. Views are nothing but a query stored in a Database. Whenever we do a select * from view, it runs the saved query and fetches data. <br /><br />Sometimes there would be a need for a huge query with many join operations between more than 10-20 tables containing millions of records and many where conditions. Especially in a datawarehousing environment or for reporting purposes. In such conditions, running the query each time whenever required, is not a feasible option. So, there should be a technique to store the data such that we should run the query only if there is a change in data in the underlying tables.<br /><br />There comes the usage of a materialized views as they can store the data they have queried . <br /><br />What are different types of Materialized views? <a href="http://www.oraclepassport.com" target="_blank"><br /><font color=red size=3 face="times">Read More....</font></a><br><br><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/1101481905086292942-8161970826572524252?l=itcompreview.blogspot.com' alt='' /></div>sippsinnoreply@blogger.com0