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Connections/Processes

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calahans

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Jun 14, 1999
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My application is running out of processes. It seems like it will need about 200. Is that a lot? Whats the max number Oracle can handle and how much memory does oracle need per connection. Whats a good rule of thumb for calculation of connections...<br><br>I can find any good information on this issue, so any help greatly appreciated!!<br><br> <p>Cal<br><a href=mailto: > </a><br><a href= > </a><br>
 
Hi Cal,<br><br>Memory usage:<br><br>I don't have the Oracle documentation to hand so this is from my (probably unreliable) memory.<br><br>Allow about 1mb per user (per connection that is.<br><br>Add the total size of the SGA (from the init.ora file for that DB)<br><br>Add the size of the oracle daemons (use the ps command to find that out)<br><br>This is pretty well documented in the &quot;Planning your database&quot; section of the Oracle manuals actually.<br><br>Processes:<br><br>This is limited by the operating system rather than Oracle. What operating system are you running the database server under?<br> <p>Mike<br><a href=mailto:michael.j.lacey@ntlworld.com>michael.j.lacey@ntlworld.com</a><br><a href= Cargill's Corporate Web Site</a><br>
 
&nbsp;&nbsp;&nbsp;The max number of processes is set in your init.ora file.&nbsp;&nbsp;However,<br>the semaphores parameter in the kernel also needs to be set high<br>enough to support Oracle and other processes, assuming that you<br>are on unix. <p>Jim Carlson<br><a href=mailto:nx56@inetarena.com>nx56@inetarena.com</a><br><a href= > </a><br>oracle, vb, some javascript
 
Thanks guys.<br><br>I'm running the database on HP-UX. <br><br>I'm trying to get a handle on this whole connection/process. In SQL Server you open a connection to a database - fair enough, and SS can handle around 65000 of these. With Oracle, as listener22 pointed out, a process can have thousands of threads. So having a hunderd processes can give you hunders of thousands of &quot;pipes&quot; to send&nbsp;&nbsp;query down (which is a equivalent to a SQL server &quot;connection&quot;. <br><br>How can I get the kernel parameters - what is the UNIX command?<br><br>How come when I connect via JDBC to the database, I'm getting a new Process rather than using an existing process and getting one of its &quot;threads&quot;?<br><br>Is this correct, or does it read like the last journal entry from a doomed artic explorer? <br><br>Thanks in advance <p>Cal<br><a href=mailto: > </a><br><a href= > </a><br>
 
&nbsp;&nbsp;&nbsp;I'm not sure that I said that a process can have thousands of <br>threads, but in any case you want to make sure that you have<br>a backup of your kernel before you make any changes.&nbsp;&nbsp;If you<br>have access to meta-link, search on 'semaphores' to get some <br>idea of the recommended values for kernel parameters.&nbsp;&nbsp;Or,<br>see the Oracle installation guide. <p>Jim Carlson<br><a href=mailto:nx56@inetarena.com>nx56@inetarena.com</a><br><a href= > </a><br>oracle, vb, some javascript
 
Cal,<br><br>In addition to the init.ora parameter re number of processes (which I didn't know about by the way, thx Jim) there are kernel parameters that limit the number of processes on HPUX. These may need to be modified as well<br><br>I'm not an SS guy but it sounds as if SS uses quite different terminology to Oracle. In Oracle you do have the multi-threaded server, but you talk about processes and not threads.<br><br>Each connection to a db implies two extra processes:<br><br>1 - A client process; this may or may not be on the database server.<br><br>2 - A server process to talk between 1 and the database daemons. <p>Mike<br><a href=mailto:michael.j.lacey@ntlworld.com>michael.j.lacey@ntlworld.com</a><br><a href= Cargill's Corporate Web Site</a><br>
 
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