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Oracle parameters - processes, session, and transactions [message #543280]

Mon, 13 February 2012 23:21

djmartin
Messages: 10181
Registered: March 2005
Location: Surges Bay TAS Australia

Senior Member
Account Moderator

G'day,

According to the documentation (http://docs.oracle.com/cd/E14072_01/server.112/e10820/initparams004.htm#i1124571):
Sessions = (1.1 * Processes) + 5
Transactions = (1.1 * Sessions)

In an instance, we have 440 transactions for 400 sessions, but the processes is 250. This would make the multiplier 1.65 not 1.1.

Could someone have a look at their 11gR2 instance and see if they have a ration of 1.1 or do you have approximately 1.6?

David

Mod: Wrong number of processes.

[Updated on: Mon, 13 February 2012 23:25]

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Re: Oracle parameters - processes, session, and transactions [message #543281 is a reply to message #543280]

Mon, 13 February 2012 23:25

BlackSwan
Messages: 26766
Registered: January 2009
Location: SoCal

Senior Member

bcm@bcm-laptop:~$ sqlplus

SQL*Plus: Release 11.2.0.1.0 Production on Mon Feb 13 21:24:06 2012

Copyright (c) 1982, 2009, Oracle.  All rights reserved.

Enter user-name: / as sysdba

Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL> show parameter process

NAME				     TYPE	 VALUE
------------------------------------ ----------- ------------------------------
aq_tm_processes 		     integer	 0
cell_offload_processing 	     boolean	 TRUE
db_writer_processes		     integer	 1
gcs_server_processes		     integer	 0
global_txn_processes		     integer	 1
job_queue_processes		     integer	 1000
log_archive_max_processes	     integer	 4
processes			     integer	 150
SQL> show parameter transaction

NAME				     TYPE	 VALUE
------------------------------------ ----------- ------------------------------
transactions			     integer	 272
transactions_per_rollback_segment    integer	 5
SQL>

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Re: Oracle parameters - processes, session, and transactions [message #543283 is a reply to message #543281]

Mon, 13 February 2012 23:33

djmartin
Messages: 10181
Registered: March 2005
Location: Surges Bay TAS Australia

Senior Member
Account Moderator

SQL*Plus: Release 11.2.0.1.0 Production on Tue Feb 14 16:30:02 2012

Copyright (c) 1982, 2009, Oracle.  All rights reserved.


Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL> sho parameter process

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
aq_tm_processes                      integer     0
cell_offload_processing              boolean     TRUE
db_writer_processes                  integer     2
gcs_server_processes                 integer     0
global_txn_processes                 integer     1
job_queue_processes                  integer     10
log_archive_max_processes            integer     4
processes                            integer     250
SQL> sho parameter transaction

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
transactions                         integer     440
transactions_per_rollback_segment    integer     5
SQL> sho parameter session

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
java_max_sessionspace_size           integer     0
java_soft_sessionspace_limit         integer     0
license_max_sessions                 integer     0
license_sessions_warning             integer     0
session_cached_cursors               integer     50
session_max_open_files               integer     20
sessions                             integer     400
shared_server_sessions               integer
SQL>

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Re: Oracle parameters - processes, session, and transactions [message #543285 is a reply to message #543281]

Mon, 13 February 2012 23:37

djmartin
Messages: 10181
Registered: March 2005
Location: Surges Bay TAS Australia

Senior Member
Account Moderator

BS,

Using
Session = (1.1 * Processes) + 5
would give
(1.1 * 150) + 5 = 170 (not 272)

Your factor is closer to 1.8

Thanks. It is good to know that other people's numbers also differ from the reference manual.

David

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Re: Oracle parameters - processes, session, and transactions [message #543286 is a reply to message #543285]

Mon, 13 February 2012 23:39

djmartin
Messages: 10181
Registered: March 2005
Location: Surges Bay TAS Australia

Senior Member
Account Moderator

oops! Your 272 is transactions. So you are closer to 1.6

David

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Re: Oracle parameters - processes, session, and transactions [message #543294 is a reply to message #543286]

Tue, 14 February 2012 00:42

ramoradba
Messages: 2457
Registered: January 2009
Location: AndhraPradesh,Hyderabad,I...

Senior Member

According to http://docs.oracle.com/cd/E11882_01/server.112/e17110.pdf

Sessions=(1.5*processes)+22 in 11g
(concurrent users, plus the number of background processes, plus approximately 10% for recursive sessions)
Transactions = (1.1 * Sessions).

Sessions(400)=(1.512*250)+22
Transaction(440)=1.1*400

http://www.orafaq.com/forum/mv/msg/172785/514743/136607/#msg_514743

Sriram Sanka

[Updated on: Tue, 14 February 2012 00:57]

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Re: Oracle parameters - processes, session, and transactions [message #543726 is a reply to message #543286]

Thu, 16 February 2012 10:14

S.Rajaram
Messages: 1027
Registered: October 2006
Location: United Kingdom

Senior Member

It was posted by Charles Hooper a week ago. Check this link.

http://hoopercharles.wordpress.com/2012/02/08/sessions-derived-value-formula-doc-bug-explains/

Regards

Raj

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Re: Oracle parameters - processes, session, and transactions [message #544072 is a reply to message #543726]

Sun, 19 February 2012 23:07

djmartin
Messages: 10181
Registered: March 2005
Location: Surges Bay TAS Australia

Senior Member
Account Moderator

@Sriram,

Thank you for the information. I was using the Oracle® Database Reference 11g Release 2 (11.2) Part Number E10820-02 August 2009 which is pointed to by the html version of the reference manual. You are referring to Oracle® Database Reference 11g Release 2 (11.2) E25513-01 September 2011. Pity they couldn't update or replace the older part number instead of using a new one.

David

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