first one.

Thank you for your response, but why ? 

 First pdf will be helpful

DC to DC converter is used to regulate the generated DC supply from solar PV panel, So that one can get better efficiency than second option...

If you are using battery for storing the generated PV power means you can go to second option, so that circuit complexity will get reduced..

Dear Natarajan,

Thank you for your response, but logically, if i use  battery it is clear that i will use the first option instead of the second option as mentioned in your answer.

If you are using battery as a storage medium than you dont want to use dc to dc converter in between source and inverter....if you are not using battery means you can use dc to dc converter to convert variable dc to fixed dc...

Firstly, the choice between dc-dc and dc-ac is dictated by the nature of the pump supply and the peridode of its operation.

If you have a solar pump that has a 12V or 24V dc power supply and you want it to work at night and / or during non-sunny periods, then you need a new generation charging regulator with an MPPT and Storage batteries. The regulator supports the charge of the batteries and the power supply of the pump. I note that the pump can work in the absence of the sun for a battery autonomy that can be fixed.

Now, if your pump's power supply is 220V AC, you need a single inverter properly sized to the power of your pump and recess the power of your photovoltaic panels. Note that these inverters are equipped with MPPT for power optimization (Inverter type pump). I would also like to remind you that it is necessary to think of the operation in non-sunlight and consequently the storage in chemical form (battery and regulator) or in the form of potential energy.

I think the choice now rests on a purely economic study.

Thank you dear prof El ghzizal, 

Hi, it is necessary to know the input and output voltage levels required

In this link you can find an example of a DC-DC converter integrated to the DC-AC converter

http://www.tandfonline.com/doi/abs/10.1080/15325008.2014.949910?journalCode=uemp20

Jumping outside the box:

I would question the premise of an AC pump rather than a DC pump ;  it may be possible to converge a 100% DC solution

Non-electrical storage may be simpler and more efficient. i.e. increasing pumping power to maximize pumping during insolation and chilling out at night

An example in common use on farms: cattle-watering systems using DC pump directly connected to panels (ideally with include MPPT controller for impedance-matching) pumping into a tank 

Tank and pump are sized to move sufficient volume during insolation period

Of course not all applications have so little constraints