VBFA Table performance

Hello All,

This is regarding VBFA table performance,

Iam using VBFA to Get Delivery numbers from Shipment and Invoice numbers from Delivery.

1st Select Statement on VBFA

By using Shipment iam getting Deliveries ,it is taking time to get the data.

here iam using all key fields in select Query.

Average Records is around 10K

2nd Select Statement on VBFA.

By using Deliveries which we get above statement am getting Billing documents.

this is taking too much time almost 30 to 40min .

here also average records around 10+K.

how to resolve this?,Please suggest is there any FM to get data from VBFA or to increase performance of select query.

Regards

Surendra.