Tables in the Qlikview data cloud are linked to other tables by a maximum of only 1 field. If more fields have the same name, a synthetic key/table is created. There are several solutions to this, but what I am looking for is some background on why Qlikview can only link on 1 field, as almost every datamodel links tables on more that one key (compound key).
I am having some problems trying to load multiple tables that share several common fields ( 3 to 4 fields are common across most of the tables, and the number of field values for the common fields are also different, sometimes being the field values of one field a subset of the values for other field ). As a result I get multiple synthetic keys ( and I guess the script load takes more time than needed due to poor performance ). In fact I am a bit lost about deciding if I should use left joins, outer joins ..etc to reduce the number of tables and get rid of the sync keys.
Reading another thread on these issues I learnt that possible solutions could be : Use of Concatenation, use of Composite keys ( as you describe here ) or use of a Key Fields Table.
for composite keys, do you know when to use Hash128, Autonumber, Autonumber128 or Autonumber256 ? Any substantial differences ?
About the other methods to avoid synthetic keys, like building a key fields table, any experience or ideas you may suggest ?
Here is the structure of the 3 tables I am using ( it looks simple, but it´s giving me a hard time ).
Thanks for any help !
Best Regards
t_MST://table with billing dates
//dimension fields
DataSet, // this field has the format YYYYMMDD
P_Prj_Nr,
Prj_WBS,
Ntw_Nr,
Activ_Nr,
//measures fields
Plan_Bill_date,
Actual_Bill_date;
t_Activ://table with schedule dates (for Gantt Chart)
//dimensions fields
DataSet,
P_Prj_Nr,
Prj_WBS,
Ntw_Nr,
Activ_Nr,
Activ_Desc,
//measures fields
Late_Start,
Late_Finish,
Actual_Start,
Actual_Finish;
t_Financials://table with costs and revenues per projects WBS
