Re: performance question

From: Joan Hsieh <joan.hsieh_at_tufts.edu>
Date: Tue, 13 Apr 2010 12:35:35 -0400
Message-ID: <4BC49D57.5060203_at_tufts.edu>


Hi all,

I got the 10053 trace file, the base statistical infor are same. However, the access ps_job table are different.

BASE STATISTICAL INFORMATION



Table Stats::

   Table: PS_JOB Alias: J2
     #Rows: 336843 #Blks: 22604 AvgRowLen: 463.00 Index Stats::

   Index: PS0JOB Col#: 5 1 2 163 164
     LVLS: 2 #LB: 1910 #DK: 336843 LB/K: 1.00 DB/K: 1.00 CLUF: 309626.00

   Index: PS1JOB Col#: 6 1 2 163 164
     LVLS: 2 #LB: 2169 #DK: 336843 LB/K: 1.00 DB/K: 1.00 CLUF: 314564.00

   Index: PS2JOB Col#: 7 1 2 163 164
     LVLS: 2 #LB: 1993 #DK: 336843 LB/K: 1.00 DB/K: 1.00 CLUF: 314222.00

   Index: PS3JOB Col#: 8 1 2 163 164
     LVLS: 2 #LB: 1870 #DK: 336843 LB/K: 1.00 DB/K: 1.00 CLUF: 310110.00

   Index: PS4JOB Col#: 9 1 2 163 164
     LVLS: 2 #LB: 1826 #DK: 336843 LB/K: 1.00 DB/K: 1.00 CLUF: 309689.00

   Index: PSAJOB Col#: 1 2 163 164 6
     LVLS: 2 #LB: 2112 #DK: 336843 LB/K: 1.00 DB/K: 1.00 CLUF: 309626.00

   Index: PSBJOB Col#: 1 2 163 164 15 12 11      LVLS: 2 #LB: 2021 #DK: 336843 LB/K: 1.00 DB/K: 1.00 CLUF: 309626.00

   Index: PSCJOB Col#: 142
     LVLS: 2 #LB: 688 #DK: 964 LB/K: 1.00 DB/K: 63.00 CLUF: 61489.00    Index: PS_JOB Col#: 1 2 163 164
     LVLS: 2 #LB: 1660 #DK: 336843 LB/K: 1.00 DB/K: 1.00 CLUF: 309626.00
Access path analysis for PS_JOB



SINGLE TABLE ACCESS PATH
   Single Table Cardinality Estimation for PS_JOB[J2]    Table: PS_JOB Alias: J2
     Card: Original: 336843.000000 Rounded: 34 Computed: 33.68 Non Adjusted: 33.68

   Access Path: TableScan

     Cost:  6152.01  Resp: 6152.01  Degree: 0
       Cost_io: 6124.00  Cost_cpu: 235247591
       Resp_io: 6124.00  Resp_cpu: 235247591
   Access Path: index (index (FFS))
     Index: PS0JOB
     resc_io: 519.00  resc_cpu: 71033682
     ix_sel: 0.000000  ix_sel_with_filters: 1.000000
   Access Path: index (FFS)
     Cost:  527.46  Resp: 527.46  Degree: 1
       Cost_io: 519.00  Cost_cpu: 71033682
       Resp_io: 519.00  Resp_cpu: 71033682
   Access Path: index (index (FFS))
     Index: PS1JOB

Bad one had the newdensity which was not in the good trace.

Access path analysis for PS_JOB



SINGLE TABLE ACCESS PATH
   Single Table Cardinality Estimation for PS_JOB[J2]    Column (#1):
     NewDensity:0.000026, OldDensity:0.000036 BktCnt:254, PopBktCnt:0, PopValCnt:0, NDV:38130

   Column (#2):
     NewDensity:0.000192, OldDensity:0.000002 BktCnt:5195, PopBktCnt:5195, PopValCnt:7, NDV:7

   Table: PS_JOB Alias: J2
     Card: Original: 336843.000000 Rounded: 1 Computed: 1.26 Non Adjusted: 1.26

   Access Path: TableScan

     Cost:  6151.99  Resp: 6151.99  Degree: 0
       Cost_io: 6124.00  Cost_cpu: 235078951
       Resp_io: 6124.00  Resp_cpu: 235078951
   Access Path: index (index (FFS))
     Index: PS0JOB
     resc_io: 519.00  resc_cpu: 70865702
     ix_sel: 0.000000  ix_sel_with_filters: 1.000000
   Access Path: index (FFS)
     Cost:  527.44  Resp: 527.44  Degree: 1
       Cost_io: 519.00  Cost_cpu: 70865702
       Resp_io: 519.00  Resp_cpu: 70865702

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Received on Tue Apr 13 2010 - 11:35:35 CDT

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