OE 11.3 and tabanalys scatter factor report on tenant?

[c3rberus]

Hello,

We are testing multi-tenancy on OE 11.3.3 (SP3) on AIX 7.1 64bit, I noticed the repot produced by tabanalys after D&L data from Default tenant into Regular tenant the scatter factor is huge!!

Before...

RECORD BLOCK SUMMARY FOR TENANT Default: 0
--------------------------------------------
                                                           -Record Size (B)-           ---Fragments--- Scatter
Table                                    Records    Size   Min   Max  Mean                Count Factor  Factor
PUB.Ld
                                         1574882  331.3M   144   431   220              2753805    1.7     1.0
PUB.Ord
                                         1700691  444.8M   181   680   274              2148526    1.3     1.0
PUB.OrdDet
                                         4706750  895.2M   118   301   199              4842898    1.0     1.0
RECORD BLOCK SUMMARY FOR TENANT oppy: 1
--------------------------------------------
                                                           -Record Size (B)-           ---Fragments--- Scatter
Table                                    Records    Size   Min   Max  Mean                Count Factor  Factor
PUB.Ld
                                               0    0.0B     0     0     0                    0    0.0     0.0
PUB.Ord
                                               0    0.0B     0     0     0                    0    0.0     0.0
PUB.OrdDet
                                               0    0.0B     0     0     0                    0    0.0     0.0

I then binary d&L the data from Defualt tenant and move it into my regular tenant and deallocated the table from the Default tenant, ran tabanalys and I get....

RECORD BLOCK SUMMARY FOR TENANT oppy: 1
--------------------------------------------
                                                           -Record Size (B)-           ---Fragments--- Scatter
Table                                    Records    Size   Min   Max  Mean                Count Factor  Factor
PUB.Ld
                                         1574882  321.9M   144   425   214              1574882    1.0     15.6
PUB.Ord
                                         1700691  508.3M   231   665   313              1700691    1.0     15.4
PUB.OrdDet
                                         4706750  922.9M   131   290   205              4706750    1.0     15.2
                                 -----------------------------------------------------------------------------
Subtotals:                               7982323    1.7G   131   665   230              7982323    1.0     14.9

The are the table is in is defined as such..
d "d64":101,64;64 /usr4/testdbs/oppy1_101.d1

It is a Type II storage area (using dbappraise.com/ppt/sos.pptx as my reference among other publications/KB) based on rough guidelines if we look at PUB.OrdDet..

BlockSize / (AvgRecSize + 20) this is 8192 / (205+20) = 36.. power of 2 this is 64 so my RPB is OK.

I tried to create a new area in the DB with the above structure definition, D&L the data, index build and run tabanlys and I get same results.. Tried specifying tenant parameter to my tabanalys but still same effect.

Anyone else run into this? Could be an issue with the report or something I am doing wrong...?

 

[TomBascom]

Scatter factor for type 2 areas doesn't mean much. Lots of empty blocks will result in large scatter factors. I hadn't previously noticed it (because I rarely look at scatter -- it just isn't useful to know) but it appears that MT negatively impacts scatter as well.