Hi @NishaRai,
take a look on my topic. My topic talk about general performance improvment but you can start from it and go more deep.
On my experience I saw a lot of enviroment without a maintainence plan or with a lot of index or with extended columns with 450 when it use for a boolean value.
about this is you use the stardard page of IIQ you must use the queries of IIQ. You can try to optimize the tables which are interested in these cases, but you risk causing damage on DB.
After a deep analisys on the data that you are reading you can growup the size of the pages of db, but you can reduce the performance for other quieres.
Additionally, you can try to reduce the entitlements in your environment, deleting unused ones.
in short: rebuild index, shrink and clean db.