Why Oracle takes 1.3GB by process in 'top' or ps -el command?

From: Huy Vu <huyv_at_usa.net>
Date: Sun, 25 Nov 2001 23:13:11 -0500
Message-ID: <3c01bec3_3@aeinews.>

Hi all,

I have an Oracle database 8.1.6 on Unixware 7.1.1 with 2GB of RAM.

The total of SGA is around 1.3GB:

Total System Global Area 1374560240 bytes

Fixed Size                    69616 bytes
Variable Size             145612800 bytes
Database Buffers         1228800000 bytes
Redo Buffers                  77824 bytes



# ps -el|grep oracle

F   S   UID PID  PPID CLS PRI NI  C     ADDR     SZ    WCHAN TTY      TIME
COMD
42 S   108 20041     1   TS  81  0  0 d8033aa0 342756 ec414168 ?       57:38
oracle
42 S   108 20043     1   TS  81  0  0 e2354540 342614 ec414198 ?       65:21
oracle
42 S   108 20072     1   TS  85  0  0 ea9ed550 342643 e970d1f0 ?        0:00

oracle

# top

last pid: 25890; load averages: 1.00, 1.00, 1.00 22:27:40
67 processes: 1 on cpu, 66 sleeping
CPU states: 98.0% idle, 0.2% user, 0.0% kernel, 1.8% wait Memory: 2304M phys, 1469M used, 835M free, 394M swapUsed, 1599M swapFree

  PID USERNAME PRI  THR  SIZE   RES STATE   TIME      CPU  COMMAND
25889 root      59    1 3952K 1068K oncpu   0:00   0.0000% top
  918 root      88    1  564K  348K sleep   0:00   0.0000% mousemgr
20072 oracle    85    1 1338M   52M sleep   0:00   0.0000% oracle
20074 oracle    85    1 1338M   52M sleep   0:00   0.0000% oracle

20068 oracle 81 1 1338M 9912K sleep 364:02 0.9998% oracle 20221 oracle 81 1 1338M 50M sleep 327:35 0.9001% oracle

The ps -el shows each oracle process takes around 342756 pages or 1338M with 'top' command.

The total of memory of Oracle processes in the column SIZE is around 30796MB (with 23 Oracle processes) while the real memory plus the swap file is around 4GB.

I think It's wrong for my calcul. Why Oracle takes 1.3GB by process while the SGA size is 1.3GB.

Could someone help me to clean up my misunderstand of Oracle SGA with Oracle process memory size as above?
I'm still newbie in that case.

Thanks in advance for any advice.

DH Received on Sun Nov 25 2001 - 22:13:11 CST