It's hard to explain this better than the man page. It's short sweet and 2 the point. But alas, I'll try anyway.
Define RAM -> http://www.techweb.com/encyclopedia/defineterm?term=ram A group of memory chips, typically of the dynamic RAM (DRAM) type, which function as the computer's primary workspace. Define virtual memory -> http://www.techweb.com/encyclopedia/defineterm?term=virtual++memory Simulating more memory than actually exists, allowing the computer to run larger programs or more programs concurrently. It breaks up the program into small segments, called "pages," and brings as many pages into memory that fit into a reserved area for that program. When additional pages are required, it makes room for them by swapping them to disk. It keeps track of pages that have been modified, so that they can be retrieved when needed again. Define "total size of the process" -> http://www.from_my_brain.dmp This is EVERYTHING it takes to run your program. The code, the process stack, variables, device drivers, shared libraries, memory mapped files (see "man -a mmap"), shared memory segments (see "man -a shmget") and all other IPC type of communications. The key word is EVERYTHING. Remember that all Oracle processes are sharing the same shared memory segment so they are all charged, or appear bigger in total size, because of that. So what it all comes down to is that on Unix machines that are running an Oracle database the "SIZE" column means just about squat. Even the more important ps command output column "RSS" is toast for database processes. So now you want to know what the "RSS" column is right. It stands for "resident set size" and is defined as "The amount of physical memory allocated to a process" (see RAM). The ps command output is good for most non Oracle processes and non Java Server Processes (don't ask). But now you are still trying to answer the question your boss asked, "How much memory is Oracle using on this server". If you are on Sun Solaris then the answer is only a click away (scroll down a bit and look for the script under "Calculate actual memory usage") -> http://renko.org/info/ora816/solaris.816/a77184/ch1.htm#39824 If you are on anything else, then a SWAG ( see the first definition - http://www.acronymfinder.com/af-query.asp?String=exact&Acronym=swag&Find=Find) will have to do. Whew!! Jerome Roa <[EMAIL PROTECTED] To: Multiple recipients of list ORACLE-L <[EMAIL PROTECTED]> u> cc: Sent by: Subject: SUN question [EMAIL PROTECTED] .com 11/25/2003 08:34 AM Please respond to ORACLE-L Does anybody know what the SZ is represents(SUN SOLARIS) ps -efly | egrep 'ora|SZ' bach# ps -efly | egrep 'oracle|SZ' S UID PID PPID C PRI NI RSS SZ WCHAN STIME TTY TIME CMD S oracle 27845 1 0 77 20596552 617600 ? 02:00:04 ? 0:26 oracleTRACS (DESCRIPTION=(LOCAL=no) S oracle 27169 1 0 51 20599536 631296 ? 23:14:36 ? 0:53 oracleTRACS (DESCRIPTION=(LOCAL=no) S oracle 521 1 0 53 202968 9528 ? Oct 04 ? 1:30 /dbopt/app/oracle/product/817/bin/t man pages states(-y converts it to Kb instead of pages): SZ (l) The total size of the process in virtual memory, including all mapped files and devices, in pages. See pagesize(1). What does this mean? Does this mean that peocess 27845 is using 617600Kb of RAM? Thanks. -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Jerome Roa INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
