In Memory table

I wanted to create a table in memory.

For that i created one TABLESPACE,one BUFFERPOOL with the following commands.

CREATE BUFFERPOOL BP3 SIZE 2000 PAGESIZE 8K

CREATE TABLESPACE USERSPACE3
PAGESIZE 8K
MANAGED BY SYSTEM
USING (‘C:\usrspace’)
EXTENTSIZE 64
PREFETCHSIZE 32
BUFFERPOOL BP3 -------------(added BUFFERPOOL BP3 to the TABLESPACE )
OVERHEAD 7.5
TRANSFERRATE 0.06

After this step i created a table in USERSPACE3 with the follwing command

CREATE TABLE AccountStatistics (
Transaction_reference_number INTEGER NOT NULL,
DEPOSIT_CNT INTEGER,
DEPOSIT_AMT FLOAT,
WITHDRAWAL_CNT INTEGER,
WITHDRAWAL_AMT FLOAT,
ATM_CREDIT_CNT INTEGER,
ATM_CREDIT_AMT FLOAT,
ATM_DEBIT_CNT INTEGER,
ATM_DEBIT_AMT FLOAT,
CASH_CREDIT_CNT INTEGER,
CASH_CREDIT_AMT FLOAT,
CASH_DEBIT_CNT INTEGER,
CASH_DEBIT_AMT FLOAT,
CLRNG_CREDIT_CNT INTEGER,
CLRNG_CREDIT_AMT FLOAT,
CLRNG_DEBIT_CNT INTEGER,
CLRNG_DEBIT_AMT FLOAT,
TRANSFER_CREDIT_CNT INTEGER,
TRANSFER_CREDIT_AMT FLOAT,
TRANSFER_DEBIT_CNT INTEGER,
TRANSFER_DEBIT_AMT FLOAT,
POS_DEBIT_CNT INTEGER,
POS_DEBIT_AMT FLOAT,
POS_CREDIT_CNT INTEGER,
POS_CREDIT_AMT FLOAT,
ACCOUNT_ID VARCHAR(20 BYTE)
)
IN USERSPACE3 ;

Then i added some one lakh records to it.

Again AccountStatistics_copy i created in disk with same data as in AccountStatistics (which is in memory)

But am not getting any performance difference between In memory table (AccountStatistics ) when i run some simple select queries.

and table which is in disk (AccountStatistics_copy )

Please help me