Database Reference
In-Depth Information
Troubleshooting Using Oracle Event Interface
The event interface provided by Oracle helps look at the behavior of a specific operation within the Oracle kernel.
For example, as mentioned in Chapter 6, “Tools and Utilities,” event 10053 will help you trace through the behavior of
Oracle's optimizer. Event 10046 will help you analyze the execution plans generated by Oracle's optimizer. Similar to
these events there are those that could help debug the parallel query operations.
Event 10708 @ Level 1—Trace RAC Buffer Cache
This event is used to trace the current RAC buffer cache to understand what is contained in the global cache and the
details. Setting this event helps look deeper into the global block content.
SQL> alter system set events '10708 trace name context forever, level 1';
System altered.
KCL: A99: anti-lock: share downconvert
GLOBAL CACHE ELEMENT DUMP (address: 0x6ffce3b20):
id1: 0x701 id2: 0x3e pkey: OBJ#513436 block: (62/1793)
lock: S rls: 0x0 acq: 0x3 latch: 0
flags: 0x20 fair: 0 recovery: 0 fpin: 'kclwh1'
bscn: 0x0.0 bctx: (nil) write: 0 scan: 0x0
lcp: 0x11c8007540 lnk: [0x11c8007598,0x11c8007598] lch: [0xabe6a3898,0xabe6a3898]
seq: 4 hist: 340 143:0 354 32
LIST OF BUFFERS LINKED TO THIS GLOBAL CACHE ELEMENT:
flg: 0x00000000 state: SCURRENT tsn: 32 tsh: 0 mode: SHR foq: 0
pin : ' kdiwh15: kdifxs' pinwait : 'gc current request'
addr: 0xabe6a3768 obj : 513436 cls: DATA bscn : 0x8e5.b1fe4cad
GCS CLIENT 0x6ffce3b98,1 resp[(nil),0x701.3e] pkey 513436.0
grant 1 cvt 2 mdrole 0x809 st 0x101 lst 0x20 GRANTQ rl LOCAL
master 5 owner 1 sid 0 remote[0x1118ea0bd8,3] hist 0x9212385
history 0x5.0x47.0x4.0x49.0x0.0x0.0x0.0x0.0x0.0x0.
cflag 0x0 sender 0 flags 0x0 replay# 0 abast (nil).x0.1
disk: 0x0000.00000000 write request: 0x0000.00000000
pi scn: 0x0000.00000000 sq[(nil),(nil)]
msgseq 0x2 updseq 0x0 reqids[2,0,0] infop (nil)
pkey 513436 .0 undo 0 stat 0 masters[32768, 1->1] reminc 12 RM# 13
flg x0 type x1 afftime x8f085144
hv 69 [stat 0x0, 5->5, wm 32768, RMno 0, reminc 10, dom 0]
kjga st 0x4, step 0.0.0, cinc 12, rmno 69, flags 0x0
lb 0, hb 0, myb 8416, drmb 8416, apifrz 0
GCS CLIENT END
SQL> alter system set events '10708 trace name context off';
The preceding output is the global cache element dump. The dissection of the dump will help understand the
current contents and contains the following information:
OBJ# is the object being mastered.
block is the data block being managed in the global cache.
bscn —Block SCN.
pin —Pin buffer number identified by “kdiwh15: kdifxs.”
 
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