Oracle and SSD

Question

Hi,
Im looking into using Flash SSD with oracle,
I know that oracle is designed to run on a magnetic disk system, but are there any settings etc that can be used to configure an oracle solution to be optomised to use flash SSD?
any help would be appriciated
Cheers

Answer 1

Exactly what limits the usefulness of the procedure. I suggest doing a profile of the system. You only use the disks that you have datafiles on.
First make a copy of the DBA_RSRC_IO_CALIBRATE table:
CREATE TABLE CAL_IO AS SELECT * FROM DBA_RSRC_IO_CALIBRATE;
Then use the following pl/sql routine to see what the effects of increasing the number of disks with fixed latency is:
set serveroutput on
Declare
v_max_iops PLS_INTEGER:=1;
v_max_mbps PLS_INTEGER:=1;
v_actual_latency PLS_INTEGER:=1;
     i integer;
begin
for i in 1..30 loop <-- change this to you max number of disks
dbms_resource_manager.calibrate_io(i,30,
max_iops=>v_max_iops,
max_mbps=>v_max_mbps,
actual_latency=>v_actual_latency);
dbms_output.put_line('Results follow: ');
dbms_output.put_line('Max IOPS: '||v_max_iops);
dbms_output.put_line('Max MBPS: '||v_max_mbps);
dbms_output.put_line('Actual Latency: '||v_actual_latency);
insert into io_cal select * from dba_rsrc_io_calibrate;
commit;
end loop;
end;
Then truncate CAL_IO (after pulling the data out into a spreadsheet) then run:
set serveroutput on
Declare
v_max_iops PLS_INTEGER:=1;
v_max_mbps PLS_INTEGER:=1;
v_actual_latency PLS_INTEGER:=1;
     i integer;
begin
for i in 10..105 loop
if (mod(i,5):=0) then
dbms_resource_manager.calibrate_io(I,30,
max_iops=>v_max_iops,
max_mbps=>v_max_mbps,
actual_latency=>v_actual_latency);
dbms_output.put_line(‘Results follow: ‘);
dbms_output.put_line(‘Max IOPS: ‘||v_max_iops);
dbms_output.put_line(‘Max MBPS: ‘||v_max_mbps);
dbms_output.put_line(‘Actual Latency: ‘||v_actual_latency);
insert into io_cal select * from dba_rsrc_io_calibrate;
commit;
end if;
end loop;
end;
To see the affects of latency variation on your ideal number of disks.
In my testing the number of disks (after getting past 3) made little difference, but increasing the max allowed latency did.
Mike