Database Technologies

In Series of New Features in Advanced Server 9.1, today I tought to write about Parition Table Syntax Supported in PPAS. In PostgreSQL and till PPAS 9.0, user has to follow method given below for partitioning a table: 1. CREATE PARENT Table, 2. Create Child tables using Inherit feature 3. Create Trigger on Partition on Parent, so that it can re-direct insert to Right Partition. 4. And if user has to add new child table, then it has to do 2 and 3 steps again. Now, in PPAS 9.0, user doesn't have to perform above activities. PPAS 9.0 supports PARTITION TABLE syntax. Lets see how PARTITION syntax in PPAS can make users/DBAs life easier. We know that PPAS/PostgreSQL supports two types of partition (Range and List). So, we will see how its simple with CREATE PARTITION SYNTAX. Lets CREATE RANGE PARTITION as we used to do in PPAS 9.0/PostgreSQL 1. Create Master table as given below: CREATE TABLE partition_master(id numeric primary key,val text); CREATE TABLE partition_child1(C...

Great News is Postgres Plus Advanced 9.1 is now available for users. So, I thought to write something about Virtual Private Database features, which is part of 9.1 Virtual Private Database (VPD) is a feature which enables Administrator to create security around actual data (i.e row/columns) so that multiple users can access data which is relevant to them. Steps which is require to create Virtual Private database is given below: 1. Create an Application Context 2. Create security policies functions 3. Apply security policies to tables Lets see how user can implement it in Advanced Server. 1. Setup an environment as given below: CREATE user merry identified by edb; CREATE user john identified by edb; CREATE TABLE public.john_merry(userid varchar2(200),val numeric); grant select,update,delete,insert on john_merry to john; grant select,update,delete,insert on john_merry to merry; 2. Now create a Policy Function as given below: CREATE OR REPLACE FUNCTION verify_user ( p_sche...