Jeremiah I _did_ say the background oracle 'processes' meaning lgwr,dbwr,ckpt threads on Win32 specifically. My understanding from the question was that he was wondering whether each user's process in a dedicated-server configuration opened all of the datafiles too
....but I might have mis-understood the question. On Fri, 29 Nov 2002, Jeremiah Wilton wrote: > On Fri, 29 Nov 2002, Jeff Herrick wrote: > > > None...only the oracle background processes (threads in Winblows) > > access the datafiles/logfiles etc. All other communication is > > done through the SGA. On some Unix variants you _can_ reach > > a file_open max kernel parameter because each process (in a > > dedicated server scenario) opens it's own stdin/stdout/stderr. > > I guess the same could be true of processes running under > > windows too. So in the limit...you could hit a wall but only > > due to the per-process overhead. > > Uh, I'm probably not going to be the only one to point out this isn't > true. I don't know about Win32 thread architecture, but in Unix and > unix-like operating systems, the shadow (server) processes each open > whatever files they need for write. It is true that they also open > the shared memory segments in order to write and read from the SGA, > but they do the reading from disk. Otherwise, which process do you > think is reading from the datafiles? > [snip] > > On Fri, 29 Nov 2002, Grant Allen wrote: > > > > > Saw an interesting post in comp.databases.oracle.server postulating that if > > > a shadow thread needed an open file handle on all files in a instance (or > > > even some of them), the process handle limit in windows could constrain user > > > scalability (e.g. too many users would result in ora-12500 unable to spawn > > > errors and the like). (Let's ignore MTS/shared server mode for the moment) > > > > > > Sounded interesting, but I thought I'd ask if anyone knows whether a shadow > > > thread (or process under unix) does open a handle on each file (control, > > > data, redo), some of them, or none of them? -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Jeff Herrick 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).
