write optimized, direct , standard dso

[Former Member]

hi,

     plz tell me in which scenario we will use write optimized dso, direct dso, standard dso??? and the exact difference between all of the 

note:don't tell that standard have 3 tables,direct and write op are having 1 table

[Former Member]

hi venkatesh,

by this time you might have some knowledge  regarding the differences and uses of both standard dso and write optimize dso,

first of all dso is data store object which supports flat structure(two dimensional ).

it has overwrite functionality where as infocube is aggregate functionality .

in sap 3.1 x standard dso is the only one used for reporting and  query designing in transactional ods is not used for reporting i.e write optimize in  sap 7.x.in sap 7.x all the three dso 's are used for reporting.

now comes the differences b/w the standard dso and write optimize dso.

standard dso there is a check box sid activation upon generation which is used for generating the report.

it has key fields,which acts as primary key , and data fields,  it acts upon record number where as in write optimize dso acts on request number (primary key) and it has semantic keys(char) and data fields(keyfigures).

standard dso has three tables

new table ,(from new table data loads to active and change log table)

active data table,(from active data table to target(infocube let say) we use  a schedular full update  as dtp)

and  change log table .(from change log table to data target tables we use  schedular as delta update as dtp).

standard dso is used for generating reports and can be used for multi providers and infosets.

Standard DSO:- -------------- Key fields-> Maxi 16. Data Fields-> 749 * Here we can place char and T char in data fields also, but we can't place KF in Key fields.

in sdso  has Activation Process  Loading is possible  Generate Export data source(Data Mart) is possible-> Delta also enabled.

in write optimize dso Export genarate data source is also possible, Delta is possible the Request no.

in standard dso has 3 tables as mentioned in the above .

but in write optimize dso has only active table .

it used for only historical data.

to use wdso in reporting we have  to pass dso into another dso.

and in write optimize dso doesn't support overwrite functionality instead it appends the data.

it takes less time for query performance since there is no need of activation of sid table upon generation.

and one more thing in change log table contain new image, space , before image , newdata, and record deletion , modification ,,,,,,,,,,,.

this are the basic differences which i know , hope u might have understood it little more ....