Case Insensitive comparison

hai

i am using postgresql 7.3.x. I am converting a database in MS SQL server to PostgreSQL.

The main problems i am facing is that in sql server the text comparisons are case insensitive. how can i compare text case insensitive in postgresql without using an upper() or lower() function in both sides (=). Is there any option to set in postgresql?
Is there any problem in overriding the = operator that compare text. ie droping the current operator = and creating a new = operator(text,text). Does the existing = operator is using internally by postgres for some porpose. please help

Another problem is in creating function...
How can i create a function that accept and return any type. the type "any" is not allowing as parameter or return type. Is it possible? i want to create a function similar to NULLIF().

jinujose

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