Remember insert because DB file sequential read affects performance-led analysis of performance reasons

Source: Internet
Author: User

With detailed 10046 trace discovery, a large number of IO waits are distributed on the following data files:
Misses in library cache during parse:0
Elapsed times include waiting on following events:
Event waited on Times Max. Wait Total waited
----------------------------------------waited----------------------
Sql*net more data from Client 47 0.00 0.00
DB file sequential read 1396 1.40 69.48
By looking at the data files that are found to correspond to the file numbers that follow file#=, respectively:
WAIT #3: nam= ' sql*net more data from client ' ela= driver id=675562835 #bytes =5 p3=0 obj#=-1 tim=2087739809552
WAIT #3: nam= ' db file sequential read ' ela= 9787 file#=203 block#=65516 blocks=1 obj#=139501 tim=2087739819840
WAIT #3: nam= ' db file sequential read ' ela= 29250 file#=88 block#=903826 blocks=1 obj#=139503 tim=2087739849887
WAIT #3: nam= ' db file sequential read ' ela= 14184 file#=86 block#=262556 blocks=1 obj#=139503 tim=2087739864826
WAIT #3: nam= ' db file sequential read ' ela= 62924 file#=89 block#=914843 blocks=1 obj#=139503 tim=2087739927918
WAIT #3: nam= ' db file sequential read ' ela= 30286 file#=86 block#=788126 blocks=1 obj#=139505 tim=2087739959072
WAIT #3: nam= ' db file sequential read ' ela= 12197 file#=85 block#=346836 blocks=1 obj#=139505 tim=2087739971677
WAIT #3: nam= ' db file sequential read ' ela= 19443 file#=89 block#=825411 blocks=1 obj#=139505 tim=2087739991255
WAIT #3: nam= ' db file sequential read ' ela= 73414 file#=89 block#=378855 blocks=1 obj#=139505 tim=2087740064903
WAIT #3: nam= ' db file sequential read ' ela= 25007 file#=87 block#=279733 blocks=1 obj#=139505 tim=2087740090218
WAIT #3: nam= ' db file sequential read ' ela= 34222 file#=86 block#=349231 blocks=1 obj#=139505 tim=2087740124718
WAIT #3: nam= ' db file sequential read ' ela= 12976 file#=87 block#=639786 blocks=1 obj#=139505 tim=2087740137987
WAIT #3: nam= ' db file sequential read ' ela= 42800 file#=87 block#=277869 blocks=1 obj#=139505 tim=2087740180951
WAIT #3: nam= ' db file sequential read ' ela= 26248 file#=203 block#=39292 blocks=1 obj#=139505 tim=2087740207500
WAIT #3: nam= ' db file sequential read ' ela= 16534 file#=88 block#=75324 blocks=1 obj#=139505 tim=2087740224369
WAIT #3: nam= ' db file sequential read ' ela= 14318 file#=87 block#=276944 blocks=1 obj#=139505 tim=2087740238924
WAIT #3: nam= ' db file sequential read ' ela= 10609 file#=15 block#=50567 blocks=1 obj#=139505 tim=2087740249666
WAIT #3: nam= ' db file sequential read ' ela= 15451 file#=86 block#=349898 blocks=1 obj#=139505 tim=2087740265319
WAIT #3: nam= ' db file sequential read ' ela= 41652 file#=89 block#=766147 blocks=1 obj#=139505 tim=2087740307199
WAIT #3: nam= ' db file sequential read ' ela= 24658 file#=86 block#=352515 blocks=1 obj#=139505 tim=2087740332184
WAIT #3: nam= ' db file sequential read ' ela= 18741 file#=87 block#=408687 blocks=1 obj#=139505 tim=2087740351201
WAIT #3: nam= ' db file sequential read ' ela= 13814 file#=87 block#=213143 blocks=1 obj#=139505 tim=2087740365202
WAIT #3: nam= ' db file sequential read ' ela= 19805 file#=85 block#=809539 blocks=1 obj#=139505 tim=2087740385174
WAIT #3: nam= ' db file sequential read ' ela= 84448 file#=88 block#=648443 blocks=1 obj#=139505 tim=2087740469831
WAIT #3: nam= ' db file sequential read ' ela= 19118 file#=14 block#=49758 blocks=1 obj#=139505 tim=2087740489121
WAIT #3: nam= ' db file sequential read ' ela= 18210 file#=85 block#=260618 blocks=1 obj#=139505 tim=2087740507502
WAIT #3: nam= ' sql*net more data from client ' ela= driver id=675562835 #bytes =1 p3=0 obj#=139505 tim=2087740508284
WAIT #3: nam= ' db file sequential read ' ela= 16073 file#=203 block#=65574 Blocks=1 obj#=139501 tim=2087740524783 fully owned, through detailed 10046 Trace, you can see that when a data is inserted, 5 to 8 different data files are written, since Oracle will look for available blocks in this tablespace, which may not necessarily be contiguous, so a large amount of time will be spent on hard drive seek, resulting in a large number of DB file sequential The Read wait event. So the remaining days of the month will continue to be slow to import data, and it is expected that the problem will be mitigated when new tablespaces are used in the next month.

Remember insert because DB file sequential read affects performance-led analysis of performance reasons

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