A Few Things To Know Regarding Databases

Following up few of the articles over the net and came across few of the facts that needed to noted down for people who are currently using databases so that they may get a bit of a help from it.

FFI va FIS:

FFI as known as Fast Full Index Scan is used to read up entire indexes in an unsorted manner. It is also called Tiny Version of table which allows the users to create a tiny table with a few columns as long as NOT NULL column is not involved in it. Fast Full Index Scan uses the Multiblok IO function and starts reading up the entire index which may include Leaf blocks in it.

FIS or as known as Full Index Scan is somewhat different that FFI since it reads up a single book. The process starts up reading up the roots and slowly shifts to reading branches and in the end it reads the leaf blocks, once the leaf blocks are done wtih, it than starts reading the bottom of the index.

Presence of Null Values in Bitmap Indexes:

Being different from the B*tree Indexes the Bitmap indexes do always index the Null Values. Each row that is present in the table is indexed by Bitmap index. It does not matter if the value is Null or Not Null in the indexes.

Working With Wide Table:

If by chance you are using a wide table for your database and there are a couple of columns are in use and need to improve the efficient performance rate of fetching records than what you need is to try out two solutions for it,

• Create an index entry on all the necessary columns and for every tiny version of table, Oracle shall put FFIS in use for them.
• The other option to optimize speed is to get two tables created, one for the frequently used columns and the other for less frequently used columns. Each time that the frequently used columns are used , Oracle will delete the less frequently table.

DDL Used For Trigger:

One of the things that the  users need to focus on is that they should use any DDL’s in triggers. Users should avoid the use of DDL’s in triggers instead post it as a job.

Easy To Connect With:

It is quite easy to connect to Databases now using 10g ward. The presence of EZCONNECT in NAMES.DIRECTORY_PATH to be used in sqlnet.ora to get an easy connection with the Database. Well if the settings are already in place then you can try using -//host:port/db to get an easy connection with the database.

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