[轉載] 瞭解raw trace檔案的各項內容

下面是metalink中的這篇文章的大體翻譯，大部分名詞用英文反而更好，就不強加翻譯了，相信大家都看得懂。當然也是比較懶的原因:-)

文字總結了trace結果原始輸出檔案中的內容。

----------------------------------------------------------------------------
APPNAME mod='%s' mh=%lu act='%s' ah=%lu
----------------------------------------------------------------------------

APPNAME：Application name setting。在Oracle 7.2和以上版本中出現。這個名稱可以由DBMS_APPLICATION_INFO包來設定。
mod：Module name
mh：Module hash value
act：Action
ah：Action hash value

比如：APPNAME mod='SQL*Plus' mh=3669949024 act='' ah=4029777240

----------------------------------------------------------------------------
PARSING IN CURSOR # len=X dep=X uid=X ct=X lid=X tim=X hv=X ad='X'
statement....
END OF STMT
----------------------------------------------------------------------------

CURSOR：Cursor number
len ：Length of SQL statement，SQL語句的長度
dep ：Recursive depth of the cursor，當前SQL語句的遞規深度，如果為0則表示是使用者提交的SQL，為1則是由於使用者SQL而導致Oracle後臺自己執行的SQL，為2則是由1級SQL繼續誘發的下一級SQL。
uid ：Schema user id of parsing user
oct ：Oracle command type.
lid ：Privilege user id.
tim ：Timestamp。在Oracle9i之前單位是1/100秒，9i則是1/1,000,000秒。利用這個值可以計算一個SQL執行了到底多長時間。這個值就是當前行被寫入trace檔案時資料庫V$TIMER檢視的值。
hv ：Hash id.
ad ：SQLTEXT address，SQLTEXT的地址，跟V$SQLAREA和V$SQLTEXT檢視中的ADDRESS欄位值相等。
statement ：The actual SQL statement being parsed.

----------------------------------------------------------------------------
PARSE ERROR #%d:len=%ld dep=%d uid=%ld ct=%d lid=%ld tim=%lu err=%d
statement....
----------------------------------------------------------------------------

PARSE ERROR ：在Oracle 7.2以上版本中解析的錯誤會寫入trace檔案中。
len ：Length of SQL statement.
dep ：Recursive depth of the statement
uid ：User id.
oct ：Oracle command type (if known).
lid ：Privilege user id.
tim ：Timestamp.
err ：Oracle error code (e.g. ORA-XXXXX) reported
statement ：The SQL statement that errored.

----------------------------------------------------------------------------
PARSE #:c=0,e=0,p=0,cr=0,cu=0,mis=0,r=0,dep=0,og=4,tim=0
EXEC #:c=0,e=0,p=0,cr=0,cu=0,mis=0,r=0,dep=0,og=4,tim=0
FETCH #:c=0,e=0,p=0,cr=0,cu=0,mis=0,r=0,dep=0,og=4,tim=0
UNMAP #:c=0,e=0,p=0,cr=0,cu=0,mis=0,r=0,dep=0,og=4,tim=0
----------------------------------------------------------------------------

PARSE ：Parse a statement. 解析一個SQL
EXEC ：Execute a pre-parsed statement. 執行已經解析完畢的SQL
FETCH ：Fetch rows from a cursor. 從遊標中得到資料，通常指select返回記錄
UNMAP ：如果遊標使用了臨時表（temporary table）, 當遊標關閉的時候將會看到UNMAP
c ：CPU time (100th's of a second in Oracle7 ,8 and 9).
e ：Elapsed time (100th's of a second Oracle7, 8. Microseconds in Oracle 9 onwards).
p ：Number of physical reads.
cr ：Number of buffers retrieved for CR reads.
cu ：Number of buffers retrieved in current mode.
mis ：Cursor missed in the cache.
r ：Number of rows processed.
dep ：Recursive call depth (0 = user SQL, >0 = recursive).
og ：Optimizer goal: 1=All_Rows, 2=First_Rows, 3=Rule, 4=Choose
tim ：Timestamp (large number in 100ths of a second).

比如：FETCH #2:c=0,e=106,p=0,cr=3,cu=0,mis=0,r=1,dep=1,og=4,tim=6005498548671

----------------------------------------------------------------------------
ERROR #%d:err=%d tim=%lu
----------------------------------------------------------------------------

執行或者fetch之後出現的SQL Error
err ：Oracle error code (e.g. ORA-XXXXX) at the top of the stack.
tim ：Timestamp.

----------------------------------------------------------------------------
STAT # id=N cnt=0 [pid=0 pos=0 bj=0 p='SORT AGGREGATE ']
----------------------------------------------------------------------------

CURSOR的執行計劃.
CURSOR ：Cursor which the statistics apply to.
id ：Line of the explain plan which the row count applies to (從1開始).
cnt ：Number of rows for this row source.
pid ：Parent id of this row source.
pos ：Position in explain plan.
obj ：Object id of row source (if this is a base object).
op ： The row source access operation.

比如：

STAT #2 id=2 cnt=0 pid=1 pos=1 bj=510 p='TABLE ACCESS BY INDEX ROWID OBJECT_USAGE (cr=2 r=0 w=0 time=83 us)'
STAT #2 id=3 cnt=1 pid=2 pos=1 bj=511 p='INDEX RANGE SCAN I_STATS_OBJ# (cr=1 r=0 w=0 time=43 us)'

----------------------------------------------------------------------------
XCTEND rlbk=%d rd_only=%d
----------------------------------------------------------------------------

XCTEND是事務結束的標誌.
rlbk ：1 if a rollback was performed, 0 if no rollback (commit).
rd_only ：1 if transaction was read only, 0 if changes occurred.

----------------------------------------------------------------------------
BINDS #%d:
bind 0: dty=2 mxl=22(22) mal=00 scl=00 pre=00 acflg=03 oacfl2=0 size=24 ffset=0
bfp=02fedb44 bln=22 avl=00 flg=05
value=10
----------------------------------------------------------------------------

BIND ：Variables bound to a cursor.
bind N ：The bind position being bound.
dty ：Data type.
mxl ：Maximum length of the bind variable (private max len in paren).
mal ：Array length.
scl ：Scale.
pre ：Precision.
oacflg ：Special flag indicating bind options
oacflg2 ：Continuation of oacflg
size ：Amount of memory to be allocated for this chunk
offset ：Offset into this chunk for this bind buffer
bfp ：Bind address.
bln ：Bind buffer length.
avl ：Actual value length (array length too).
flg ：Special flag indicating bind status
value ：The actual value of the bind variable.

比如：

BINDS #4:
bind 0: dty=2 mxl=22(22) mal=00 scl=00 pre=00 acflg=08 oacfl2=1 size=24 ffset=0
bfp=ffffffff7ce64ee0 bln=22 avl=01 flg=05
value=0
bind 1: dty=1 mxl=32(11) mal=00 scl=00 pre=00 acflg=18 oacfl2=1 size=32 ffset=0
bfp=ffffffff7ce6b128 bln=32 avl=11 flg=05
value="TABCOMPART$"
bind 2: dty=2 mxl=22(22) mal=00 scl=00 pre=00 acflg=08 oacfl2=1 size=24 ffset=0
bfp=ffffffff7ce6bae8 bln=24 avl=02 flg=05
value=1

----------------------------------------------------------------------------
WAIT #: nam="" ela=0 p1=0 p2=0 p3=0
----------------------------------------------------------------------------

WAIT ：An event that we waited for.
nam ：What was being waited for.
ela ：Elapsed time for the operation.
p1 ：P1 for the given wait event.
p2 ：P2 for the given wait event.
p3 ：P3 for the given wait event.

比如 (Full Table Scan):
WAIT #1: nam="db file scattered read" ela= 5 p1=4 p2=1435 p3=25
在遊標1上經歷了"db file scattered read"等待事件，一共等了0.05秒，在讀取File 4，從1435 block開始，讀了25個block

比如 (Index Scan):
WAIT #1: nam="db file sequential read" ela= 4 p1=4 p2=1224 p3=1
在遊標1上經歷了"db file sequential read"等待事件，一共等了0.04秒，在讀取file 4，block 1224，讀取了這一個block

對於每一個等待事件的含義和p1,p2,p3表示的意思，可以參考文件的章節。