Calculation Scripts:- Session 10
Data Blocks:
In Block Storage
databases, Essbase uses two types of structure to store data:
1. Data Blocks
2. Index Blocks
Lets go in flashback.
We all know that the dimensions can be categorized in sparse and dense
type and
data is not stored for a member but its stored at a member combination. In
our
application we have 5 dimensions, which are of type:
Stored Members in
Accounts * Stored Members in Period * 8 will be the block size in Bytes
13*19*8 = 1976 Bytes
will be our block size
"The number of
stored members in sparse Dimensions will help us in finding potential number of
blocks"
Potential Number of
Blocks = Stored Members in Entity * Stored Members in Year * Stored Members in
Scenario;
13*6*4= 312;
Lets clear all data of
our cube and check the statistics, to check the statistics: Right click on
database->Edit->Properties
If you will notice,
the block size here is 1976 bytes, Potential number of blocks is 312 as we
have calculated above and because we have cleared all data from this
cube existing number of
blocks are 0. Lets lock and send below
data to the Essbase cube and check the statistics:
Now why the existing
number of block and level 0 blocks increased to 1 ?
To answer this let
check at which combination this data is stored in Essbase:
Budget->Fy10->APAC1->Jan->GrossSales
= 12300
Budget->Fy10->APAC1->Feb->GrossSales
= 12400
Budget->Fy10->APAC1->Mar->GrossSales
= 21300
Budget,Fy10, APAC1
these there members are from sparse dimensions, they will make an
entry in
index file and every entry in an index file has a data
file associated with it. Though
Essbase has it own format for
index and data file but for understanding lets assume that below
is the format:
What if we have
following data in the Essbase:
Budget->Fy10->APAC1->Jan->GrossSales
= 12300
Budget->Fy10->APAC1->Feb->GrossSales
= 12400
.
.
.
Budget->Fy10->APAC1->Dec->GrossSales
= 14100
Budget->Fy10->APAC1->Jan->ThirdParty
= 5000
Budget->Fy10->APAC1->Feb->ThirdParty
= 5025
.
.
.
Budget->Fy10->APAC1->Dec->ThirdParty
= 5275
.
.
.
Budget->Fy10->APAC1->Dec->OverHead
= 475
Still for all the
combination the sparse member combination is same so there is no need to
have
an extra entry in the index file just the data associated with this combination
needs to be
modified.
Now lets assume if you
lock and send these values to Essbase:
Now the combination at
which data will be stored:
Budget->Fy10->APAC1->Jan->GrossSales
= 12300
Budget->Fy10->APAC1->Feb->GrossSales
= 12400
Budget->Fy10->APAC1->Mar->GrossSales
= 21300
Budget->Fy10->APAC1->Apr->GrossSales
= 14000
Budget->Fy10->APAC2->Jan->GrossSales
= 12300
Budget->Fy10->APAC2->Feb->GrossSales
= 12400
Budget->Fy10->APAC2->Mar->GrossSales
= 21300
Budget->Fy10->APAC2->Apr->GrossSales
= 17000
Now for first four
data entries we have the same set of sparse dim combination (Budget,Fy10,
APAC1) and this combination is already a part of index file but the next
four data entries are for Budget,Fy10, APAC2 so there will be one more entry in
the index file and this will point to a new data block in the data file.
If you look at the
statistics
Its a bit complicated
for beginners, if you have any question on this please feel free to shoot.
Cheers..!!!
Rahul S.
Rahul S.
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