Yes, I meant "files they need for read."

No matter how many times you proofread before sending...

A shadow server process would only write if it were using direct path
insert /*+append*/ or sqlldr or sorting to TEMP.

--
Jeremiah Wilton
http://www.speakeasy.net/~jwilton

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?
> 
> A sample lsof of a typical server process:
> unixhost# lsof -p 29290
> COMMAND     PID   USER   FD   TYPE     DEVICE   SIZE/OFF  NODE NAME
> oracleorc 29290 oracle  cwd   VDIR 64,0x10002      22528 10090 
>/oracle/product/8.1.7/dbs
> oracleorc 29290 oracle  mem   VREG     64,0x7        532 20465 /var/spool/pwgr/status
> oracleorc 29290 oracle  txt   VREG 64,0x10002   38558888 22842 
>/oracle/product/8.1.7/bin/oracle
> oracleorc 29290 oracle  mem   VREG     64,0x6      13215  3024 /usr/lib/tztab
> oracleorc 29290 oracle  mem   VREG     64,0x6    1572640  6873 
>/usr/lib/pa20_64/libc.2
> oracleorc 29290 oracle  mem   VREG     64,0x6     274664  8414 
>/usr/lib/pa20_64/libm.2
> oracleorc 29290 oracle  mem   VREG     64,0x6      24032  8484 
>/usr/lib/pa20_64/libdl.1
> oracleorc 29290 oracle  mem   VREG     64,0x6      23336  2688 
>/usr/lib/pa20_64/libnss_dns.1
> oracleorc 29290 oracle  mem   VREG     64,0x6     131264 19010 
>/usr/lib/pa20_64/libpthread.1
> oracleorc 29290 oracle  mem   VREG     64,0x6      24896  2671 
>/usr/lib/pa20_64/librt.2
> oracleorc 29290 oracle  mem   VREG 64,0x10002      40600  3388 
>/oracle/product/8.1.7/lib64/libdsbtsh8.sl
> oracleorc 29290 oracle  mem   VREG 64,0x10002    7101192  3390 
>/oracle/product/8.1.7/lib64/libjox8.sl
> oracleorc 29290 oracle  mem   VREG     64,0x6     289000  8482 
>/usr/lib/pa20_64/dld.sl
> oracleorc 29290 oracle    0r  VCHR      3,0x2        0t0    66 /dev/null
> oracleorc 29290 oracle    1w  VREG     64,0x5       1177  6173 
>/tmp/listener_L_ORCL_start.out
> oracleorc 29290 oracle    2w  VREG     64,0x5       1177  6173 
>/tmp/listener_L_ORCL_start.out
> oracleorc 29290 oracle    3r  VCHR      3,0x2        0t0    66 /dev/null
> oracleorc 29290 oracle    4r  VCHR      3,0x2        0t0    66 /dev/null
> oracleorc 29290 oracle    5r  VCHR      3,0x2        0t0    66 /dev/null
> oracleorc 29290 oracle    6u  inet 0x4ecd0668        0t0   TCP *:* (IDLE)
> oracleorc 29290 oracle    7r  VCHR      3,0x2        0t0    66 /dev/null
> oracleorc 29290 oracle    8u  unix 0x4a1c8e00        0t0       
>/var/spool/sockets/pwgr/client29290
> oracleorc 29290 oracle    9r  VREG 64,0x10002     360448  2274 
>/oracle/product/8.1.7/rdbms/mesg/oraus.msb
> oracleorc 29290 oracle   10u  VCHR 64,0x3000e 0x512bc000  2233 
>/dev/data3/rorclsession_item-01
> oracleorc 29290 oracle   11u  inet 0x515d3a68  0t1684264   TCP 
>unixhost.corporation.com:1541->clienthost.corporation.com:1577 (ESTABLISH
> ED)
> oracleorc 29290 oracle   12u  VCHR 64,0x3000f  0x842c000  2237 
>/dev/data3/rorclts1_idx-02
> oracleorc 29290 oracle   13u  VCHR 64,0x10078  0xaacc000  2197 /dev/data1/rorclts1-02
> oracleorc 29290 oracle   14u  VCHR 64,0x2006a 0t59826176  2203 
>/dev/data2/rorclts1_idx-01
> oracleorc 29290 oracle   15u  VCHR 64,0x1006d  0xad0a000  2050 /dev/data1/rorclts1-01
> oracleorc 29290 oracle   16u  VCHR 64,0x20078 0t89505792  2231 /dev/data2/rorclts2-01
> oracleorc 29290 oracle   17u  VCHR 64,0x30015 0x16aa2000  2248 
>/dev/data3/rorclts3_idx-02
> oracleorc 29290 oracle   18u  VCHR 64,0x20073 0x6a144000  2221 
>/dev/data2/rorclts3_idx-01
> oracleorc 29290 oracle   19u  VCHR 64,0x30010 0x3819c000  2239 
>/dev/data3/rorclts4_idx-02
> oracleorc 29290 oracle   20u  VCHR 64,0x20072 0x375a8000  2219 
>/dev/data2/rorclts4_idx-01
> oracleorc 29290 oracle   21u  VCHR 64,0x1006f 0x77b6a000  2179 /dev/data1/rorclts3-01
> oracleorc 29290 oracle   22u  VCHR 64,0x10079 0x75c94000  2199 /dev/data1/rorclts3-02
> 
> --
> Jeremiah Wilton
> http://www.speakeasy.net/~jwilton
> 
> > 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?
> 
> 

-- 
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-- 
Author: Jeremiah Wilton
  INET: [EMAIL PROTECTED]

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