Memory Usage 8i vs 7.3.2

From: Richard Brown (SPSD EAME) <Richard.Brown_at_bedford.waii.com>
Date: 2000/08/11
Message-ID: <3994232C.6B6310C0@bedford.waii.com>#1/1

Has anyone noticed, or have an explanation for the massive increase in memory resources required on a system after moving from Oracle 7.3.2.1 to 8i. I noticed this on a Sun Ultra 10 (500Mb RAM) with Solaris 2.6 after building a new 8i db and instance with identical init.ora parameters to an existing 7.3.2.1 db.

Although the SGA was about 10% bigger, the system memory usage was a massive 360% more (even if you don't include the two new processes). I realise there are a raft of new default init parameters which may affect SGA size, and possibly account for the 10% difference, but what on earth is causing the hike in system memory????

7.3.2.1

Total System Global Area       5859944 bytes
Fixed Size                       39696 bytes
Variable Size                  4530008 bytes
Database Buffers               1126400 bytes
Redo Buffers                    163840 bytes


**************************************************************************************************

ps -lfe returns :

 F S      UID   PID  PPID  C PRI NI     ADDR     SZ    WCHAN    STIME TTY      TIME CMD
 8 S   oracle 19376     1  0  40 20 61454068   2612 60ebc03c 16:19:26 ?        0:01
ora_dbwr_db7
 8 S   oracle 19378     1  0  40 20 60ff0db8   2612 60ebc04c 16:19:26 ?        0:01
ora_lgwr_db7
 8 S   oracle 19380     1  0  41 20 628e6e70   2475 60ebc05c 16:19:26 ?        0:00
ora_smon_db7
 8 S   oracle 19374     1  0  40 20 61dd69a8   2470 60ebc02c 16:19:26 ?        0:00

ora_pmon_db7

Size of processes = (Sum of SZ * 8) = 81352 Kb (79 Mb).

8i (8.1.5.1)

Total System Global Area                          6540688 bytes
Fixed Size                                          64912 bytes
Variable Size                                     5169152 bytes
Database Buffers                                  1126400 bytes
Redo Buffers                                       180224 bytes


**************************************************************************************************

ps -lfe returns :

 F S      UID   PID  PPID  C PRI NI     ADDR     SZ    WCHAN    STIME TTY      TIME CMD
 8 S   oracle 19475     1  0  41 20 61334880   9125 60ebc07c 16:42:22 ?        0:00
ora_dbw0_db8
 8 S   oracle 19477     1  0  41 20 60ff0db8   9116 60ebc08c 16:42:22 ?        0:00
ora_lgwr_db8
 8 S   oracle 19481     1  3  40 20 61dd69a8   9119 60ebc0ac 16:42:22 ?        0:01
ora_smon_db8
 8 S   oracle 19473     1  0  41 20 61dd4ea8   9184 60ebc06c 16:42:21 ?        0:00

ora_pmon_db8

Size of processes = (Sum of SZ * 8) = 292352 Kb (285 Mb).

8 S oracle 19483 1 0 41 20 61dd5c28 9110 60ebc0bc 16:42:22 ? 0:00 ora_reco_db8
8 S oracle 19479 1 0 41 20 628e82b0 9113 60ebc09c 16:42:22 ? 0:00 ora_ckpt_db8

Size including the two extras = 438136 Kb (428 Mb)

Where SZ = The total size of the process in virtual memory, including all mapped files and devices, in pages. Where page size = 8192 bytes.

Thanks Richard. Received on Fri Aug 11 2000 - 00:00:00 CDT