Hi gurus,

a simple performance question:
Since some weeks I'm responsible for the administration of a 8i database on
Solaris 8 / Sun Fire 280R with 2GB Memory. Nothing else runs on the server.
With the OS-commands top and vmstat i see more or less 500 MB of free memory
and 1GB swap in use. The database runs as dedicated server, so 500MB free
memory happens with 10-12 dedicated sessions. At peak times we expect up to
40 sessions, so that free memory is expected to decrease to 200 MB free
memory (Made a test already). The question now is: What is better? To
increase the SGA, so that the database always will use more memory or to
reserve some memory for the dedicted sessions?

Performance AT THE MOMENT with 10 sessions is fine (In Memory Sort ratio,
Hit Buffer Cache, Hit Library Cache, Hit Data Dictionary all above 98%) and
the page scan rate doesn't show a shortage in memory.

show sga;
Total System Global Area 413892768 bytes
Fixed Size 73888 bytes
Variable Size 157900800 bytes
Database Buffers 255377408 bytes
Redo Buffers 540672 bytes

The size of the database in total is 4 GByte with system.dbf 270MB,
maintables.dbf 550MB, othertables.dbf 2GB, mainindexes.dbf 500MB,
otherindexes.dbf 200MB.

Output of prstat -u oracle8i
PID USERNAME SIZE RSS STATE PRI NICE TIME CPU PROCESS/NLWP
16402 oracle8i 444M 425M sleep 59 0 0:14.26 0,5% oracle/11
16554 oracle8i 443M 424M sleep 10 0 0:07.54 0,0% oracle/11
16480 oracle8i 433M 414M sleep 38 0 0:00.07 0,0% oracle/11
16485 oracle8i 429M 409M sleep 58 0 0:00.00 0,0% oracle/1
16615 oracle8i 441M 422M sleep 4 0 0:03.35 0,0% oracle/11
7078 oracle8i 528M 498M sleep 59 0 2:37.50 0,0% oracle/11
10786 oracle8i 1936K 328K sleep 58 0 0:00.00 0,0% sh/1
16563 oracle8i 442M 423M sleep 44 0 0:00.50 0,0% oracle/11
16487 oracle8i 442M 424M sleep 58 0 0:03.51 0,0% oracle/11
16459 oracle8i 441M 422M sleep 52 0 0:04.21 0,0% oracle/11
16467 oracle8i 441M 422M sleep 50 0 0:07.03 0,0% oracle/11
16789 oracle8i 432M 413M sleep 42 0 0:00.23 0,0% oracle/11
7068 oracle8i 430M 399M sleep 59 0 0:01.20 0,0% oracle/11
7082 oracle8i 533M 503M sleep 59 0 2:45.43 0,0% oracle/11
16644 oracle8i 430M 410M sleep 55 0 0:00.00 0,0% oracle/1
7084 oracle8i 430M 399M sleep 59 0 0:00.17 0,0% oracle/21
16543 oracle8i 439M 419M sleep 58 0 0:00.03 0,0% oracle/11
7080 oracle8i 531M 501M sleep 59 0 0:06.17 0,0% oracle/11
7066 oracle8i 435M 404M sleep 59 0 0:00.16 0,0% oracle/258
7070 oracle8i 430M 399M sleep 59 0 0:01.00 0,0% oracle/11
7074 oracle8i 429M 402M sleep 59 0 0:00.00 0,0% oracle/1
7072 oracle8i 430M 404M sleep 34 0 0:00.54 0,0% oracle/1
7076 oracle8i 536M 507M sleep 59 0 7:54.58 0,0% oracle/11
294 oracle8i 9560K 3304K sleep 58 0 0:00.21 0,0% tnslsnr/1
16651 oracle8i 434M 413M sleep 48 0 0:00.00 0,0% oracle/1
7064 oracle8i 429M 398M sleep 59 0 0:00.00 0,0% oracle/1

Robert



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