We got a brand new SUN T5140, and I managed to get my hands on it to run some tests.
Glenn Fawcett wrote some interresting entries in his blog about these so called chip multithreading CPUs. 2 should be mentioned here, as they had influence to this test-case:
Oracle's vision of multi-core processors on Solaris and Virtual CPUs effect on Oracle SGA allocations.
I wanted to know which parameters are derived from cpu_count.
A fresh installed and patched RDBMS 18.104.22.168.0 was my victim.
I used this script to get my data:
#!/usr/bin/ksh -x integer i=1 while ((i <= 128)); do print " $i "; echo "*.compatible='22.214.171.124.0' *.control_files='/appl/oracle/oradata/BERX2/control01.ctl','/appl/oracle/oradata/BERX2/control02.ctl','/appl/oracle/oradata/BERX2/control03 .ctl' *.db_block_size=8192 *.db_name='BERX2' *.MEMORY_MAX_TARGET=16G *.SGA_TARGET=13G *.cpu_count=$i"> initBERX2.ora echo "startup pfile='/appl/oracle/product/126.96.36.199/dbs/initBERX2.ora' ; insert into init_parameters select $i , a.ksppinm , b.ksppstvl , c.ksppstvl from x\$ksppi a, x\$ksppcv b, x\$ksppsv c where a.indx = b.indx and a.indx = c.indx; commit; select distinct(\"CPUs\") from init_parameters; shutdown; exit;"> cpus/doit$i.sql sqlplus "/ as sysdba" @cpus/doit$i.sql >cpus/log$i.log sleep 5 (( i = i + 1)); done
Afterwards I just had to get the interresting data out:
select /*+ PARALLEL */ i."CPUs" || ',' || i."Parameter" || ',' || i."InstanceValue" from init_parameters i where "Parameter" in (select distinct(i1."Parameter") from init_parameters i1, init_parameters i2 where i1."Parameter" = i2."Parameter" and i1."CPUs" <> i2."CPUs" and i1."InstanceValue" <> i2."InstanceValue" ) order by i."CPUs", i."Parameter";
and waste my time in excel creating the graphs:
(the whole spool output can be found here.)