Powerful ad on anti-terrorism on the eve of Ramadan..!!!

FBI – Function Based Index (for user defined functions)

FBI is one of the index types that is supported by oracle. It more or less behaves like other type of b*tree indexes(unique,non-unique,reverse) but only difference is the way it builds the index table. In this, when it builds Index table, index value is derived by applying the user defined function on the table data. So, index data value and actual table data value would be different here. FBI is simply an index that uses the function so that the database can make direct comparisons between the index values and the filter values. This FBI index can be created on a single column or more than one column. More than one FBI can be created for the same data table but for the different columns. HOW TO VERIFY: How to verify whether the created index is FBI or not? Fire this query, select index_type from user_indexes where index_name = 'TOTAL_SAL_INDX' ð This query would return “ FUNCTION-BASED NORMAL ” (it means it is B*Tree index but of “FBI” type) LITTLE-KNOWN FACTS TO BE REM...

Cluster Table

Cluster Table is the another type of table which is supported by Oracle. A cluster is a schema object that contains one or more tables that all have one or more columns in common. Rows of one or more tables that share the same value in these common columns are physically stored together within the database. A cluster is to store data for more than 1 table in the same block. Tables which are created upon this cluster are called as “Cluster Table”. Cluster Index is an index which is created for this cluster. HOW TO VERIFY: How to verify whether the created table is “Cluster Table” or not? Fire this query, Select distinct cluster_name from user_all_tables where table_name IN ('EMPLOYEE',’DEPARTAMENT’) ð This query would return the name of the cluster (eg., query returns “CLUSTER_DEPT_ID” if it is the created cluster’s name) LITTLE-KNOWN FACTS TO BE REMEMBERED: · Clustered Index doesn’t occupy any memory space though it is creat...

Socialism : A simple test to understand it

An economics professor at a local college made a statement that he had never failed a single student before, but had recently failed an entire class. That class had insisted that Obama's socialism worked and that no one would be poor and no one would be rich, a great equalizer. The professor then said, "OK, we will have an experiment in this class on Obama's plan". All grades will be averaged and everyone will receive the same grade so no one will fail and no one will receive an A.... (substituting grades for dollars - something closer to home and more readily understood by all). After the first test, the grades were averaged and everyone got a B. The students who studied hard were upset and the students who studied little were happy. As the second test rolled around, the students who studied little had studied even less and the ones who studied hard decided they wanted a free ride too so they studied little.. The second test average was a D! No one was happy....

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