Why Partial Reload script?

[poonam_kulwal]

T1:
Load * inline
[EmployeKey,FirstName];   
              
//===Part 1
for Each vMonth in $(vMonthList)
     if filetime('..\Partial Reload\Employee_$(vMonth).xlsx') <> null then
     Concatenate(T1)
     LOAD EmployeKey,
      FirstName
     FROM
     [..\Partial Reload\Employee_$(vMonth).xlsx]
     (ooxml, embedded labels, table is Sheet1);
     ENDIF
next

//===Part 2
if filetime('..\Partial Reload\Employee_$(previousMonth).xlsx') <> null then 
ADD ONLY LOAD EmployeKey,
      FirstName
     FROM
     [..\Partial Reload\Employee_$(previousMonth).xlsx]
     (ooxml, embedded labels, table is Sheet1)
     where not Exists(EmployeKey);
ENDIF

//===Part 3
if filetime('..\Partial Reload\Employee_$(thisMonth).xlsx') <> null then
ADD ONLY LOAD EmployeKey,
      FirstName
     FROM
     [..\Partial Reload\Employee_$(thisMonth).xlsx]
     (ooxml, embedded labels, table is Sheet1)
     where not Exists(EmployeKey) ;
ENDIF

 

I have difficulty understanding significance of above script.

Part 1 does load all excel files from the specified directory including thisMonth and previousMonth .

Then why Part 2 and Part 3 has been written in the script.

Isn’t it loading thisMonth and previousMonth files again with check for duplicate values? 

I know it is a Partial reload and it will execute only when script is executed using Ctr+Shift+R.

I have a autosys job that does reload of my qvw file (means full reload). Then how Partial Reload script will come into picture?

What is the significance of writing down Partial Reload in the above script (although I am doing full load all the time)?

This is sample script. Actual qvw is 2 GB in size.

 Appreciate your explanation on above.

Thanks,

Poonam

[Vegar]

The reason for implementing partial reload is mainly to reduce reload times, you don't need to reload all tables in the whole script. It is also possible to add an early exit script to avoid reading through the whole thing.

I think you have misunderstood your script. Part 1 does not execute when you do a partial reload only new EmployeKey rows in part 2 and part 3 are added to your datamodel.

Partial reload executes only statements preceded by Replace or Add prefix such as ADD LOAD. Other data tables, with normal LOAD remain unaffected by the command.

[poonam_kulwal]

But I am doing full reload for my qvw through autosys job every day.

My concern is, how come Partial Reload will come into picture? Why Partial reload is written in the script?

[Vegar]

My guess is that the partial reload is created my a developer that wanted
to reduce load duration during development.

For normal reload it will not have any effect (except for a slightly
increased load duration hence you are looking through two sheets an extra
time)