If we configure out namespace with everything data in DRAM mode and configure my box to use SSD as additional RAM (i.e swap space) , will this configuration give me better performance compared to hybrid appraoch of storing Indexes in DRAM and data on SSD
I think hybrid approach will probably give you better performance than swapping.
I was also thinking the same based on my assumption that the way aerospike stores data on disk is different the way it will store data in RAM
Would be helpful if you can tell the reason you think hybrid would be better ?
Because Aerospike has highly optimized how it uses the SSDs. The way the write blocks are sized and written to SSDs in a log structured fashion including their defrag cycles, it ensures that SSDs wear out evenly. Their ACT tool is used by SSD manufacturers to benchmark their drives. http://www.aerospike.com/blog/act-ssd-benchmark/
On the other hand, see more about swapping here [SOLVED] Swap On SSD; Is It As Fast As More RAM?
Other things being equal, I would think that a narrower use case (Aerospike’s data read and write) will be better optimized than a general use case (swapping).