Comments on: Buffer Busy Waits and Disk file operations I/O http://dboptimizer.com/2012/01/19/buffer-busy-waits-and-disk-file-operations-io/ database performance, SQL tuning and data visualizatoin Tue, 02 Oct 2012 12:01:09 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: Kyle Hailey http://dboptimizer.com/2012/01/19/buffer-busy-waits-and-disk-file-operations-io/#comment-1571 Kyle Hailey Wed, 16 May 2012 21:17:30 +0000 http://dboptimizer.com/?p=2014#comment-1571 @Vincent: what version of Oracle are you on? What database host O/S are you using? Are you using dNFS? Would be interested to hear more about what you are seeing. - Kyle @Vincent: what version of Oracle are you on? What database host O/S are you using? Are you using dNFS?
Would be interested to hear more about what you are seeing.
- Kyle

]]> By: Vincent Deygas http://dboptimizer.com/2012/01/19/buffer-busy-waits-and-disk-file-operations-io/#comment-1567 Vincent Deygas Wed, 16 May 2012 07:38:50 +0000 http://dboptimizer.com/?p=2014#comment-1567 <a href="#comment-1119" rel="nofollow">@Kyle Hailey</a> Same issue here. Any news on your side ? Regards, Vincent. @Kyle Hailey
Same issue here.
Any news on your side ?

Regards,
Vincent.

]]> By: Kyle Hailey http://dboptimizer.com/2012/01/19/buffer-busy-waits-and-disk-file-operations-io/#comment-1119 Kyle Hailey Thu, 19 Jan 2012 19:06:53 +0000 http://dboptimizer.com/?p=2014#comment-1119 @Yong Huang: thanks , looks encouraging: FUNCTION_ID FUNCTION_NAME ----------- ------------------------------ 0 RMAN 1 DBWR 2 LGWR 3 ARCH 4 XDB 5 Streams AQ 6 Data Pump 7 Recovery 8 Buffer Cache Reads 9 Direct Reads 10 Direct Writes 11 Smart Scan 12 Archive Manager 13 Others which would make it an issue of LGWR on a DATAFILE. Will look into LGWR issues and follow up. Thanks @Yong Huang: thanks , looks encouraging:
FUNCTION_ID FUNCTION_NAME
———– ——————————
0 RMAN
1 DBWR
2 LGWR
3 ARCH
4 XDB
5 Streams AQ
6 Data Pump
7 Recovery
8 Buffer Cache Reads
9 Direct Reads
10 Direct Writes
11 Smart Scan
12 Archive Manager
13 Others
which would make it an issue of LGWR on a DATAFILE.
Will look into LGWR issues and follow up.
Thanks

]]> By: Yong Huang http://dboptimizer.com/2012/01/19/buffer-busy-waits-and-disk-file-operations-io/#comment-1116 Yong Huang Thu, 19 Jan 2012 15:44:20 +0000 http://dboptimizer.com/?p=2014#comment-1116 Instead of DBA_HIST_IOSTAT_FILETYPE (thanks to Andy Klock), why not DBA_HIST_IOSTAT_FILETYPE_NAME? Instead of DBA_HIST_IOSTAT_FILETYPE (thanks to Andy Klock), why not DBA_HIST_IOSTAT_FILETYPE_NAME?

]]> By: Pawel Kwiatkowski http://dboptimizer.com/2012/01/19/buffer-busy-waits-and-disk-file-operations-io/#comment-1112 Pawel Kwiatkowski Thu, 19 Jan 2012 12:57:30 +0000 http://dboptimizer.com/?p=2014#comment-1112 This is only my speculation and may be a dead end, but... :) Take a look at some constants defined in /usr/include/fcnttl.h. Providing this is a correct assumption, FileOperation=2 would indicate _FWRITE operation and filetype=2 (data file). Possibly DBWR blocks other sessions. ... #define _FREAD 0x00000001 #define _FWRITE 0x00000002 #define _FNONBLOCK 0x00000004 #define _FAPPEND 0x00000008 #define _FSYNC 0x00000010 #define _FEXEC 0x00000020 #define _FSNAPSHOT 0x00000040 #define _FCIO 0x00000080 #define _FCREAT 0x00000100 #define _FTRUNC 0x00000200 #define _FEXCL 0x00000400 #define _FNOCTTY 0x00000800 #define _FRSHARE 0x00001000 #define _FDEFER 0x00002000 #define _FDELAY 0x00004000 #define _FNDELAY 0x00008000 #define _FNSHARE 0x00010000 #define _FASYNC 0x00020000 #define _FMOUNT 0x00040000 #define _FSYNCALL 0x00080000 #define _FNOCACHE 0x00100000 #define _FREADSYNC 0x00200000 #define _FDATASYNC 0x00400000 #define _FDEFERIND 0x00800000 #define _FDATAFLUSH 0x01000000 #define _FCLREAD 0x02000000 #define _FLARGEFILE 0x04000000 #define _FDIRECT 0x08000000 #define _FDOCLONE 0x10000000 #define _FALT 0x20000000 #define _FKERNEL 0x40000000 #define _FMSYNC 0x80000000 ... This is only my speculation and may be a dead end, but… :)

Take a look at some constants defined in /usr/include/fcnttl.h. Providing this is a correct assumption, FileOperation=2 would indicate _FWRITE operation and filetype=2 (data file). Possibly DBWR blocks other sessions.

…
#define _FREAD 0×00000001
#define _FWRITE 0×00000002
#define _FNONBLOCK 0×00000004
#define _FAPPEND 0×00000008
#define _FSYNC 0×00000010
#define _FEXEC 0×00000020
#define _FSNAPSHOT 0×00000040
#define _FCIO 0×00000080
#define _FCREAT 0×00000100
#define _FTRUNC 0×00000200
#define _FEXCL 0×00000400
#define _FNOCTTY 0×00000800
#define _FRSHARE 0×00001000
#define _FDEFER 0×00002000
#define _FDELAY 0×00004000
#define _FNDELAY 0×00008000
#define _FNSHARE 0×00010000
#define _FASYNC 0×00020000
#define _FMOUNT 0×00040000
#define _FSYNCALL 0×00080000
#define _FNOCACHE 0×00100000
#define _FREADSYNC 0×00200000
#define _FDATASYNC 0×00400000
#define _FDEFERIND 0×00800000
#define _FDATAFLUSH 0×01000000
#define _FCLREAD 0×02000000
#define _FLARGEFILE 0×04000000
#define _FDIRECT 0×08000000
#define _FDOCLONE 0×10000000
#define _FALT 0×20000000
#define _FKERNEL 0×40000000
#define _FMSYNC 0×80000000
…

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