Load

[qlikview979]

Hi experts,

What is partial reload ?

[awhitfield]

Hi It's used when you only want specific tables to be refreshed rather than all of the them:

This command executes only Load and Select (SQL) statements preceded by a Replace or Add prefix. Other data tables remain unaffected by the command. Check the QV help file for further information.

Regards

Andy

[vikasmahajan]

Q: What is Partial Reload?

A partial load is a load that will complete a previous normal load. That is not the same as an incremental one. First you do a complete load. Second you (often the user) do a partial load in order to get the last data that have been updated since the complete load. This technique avoids performing a complete load several times especially if very few data are updated several times, and the complete load takes too much time to get done by a user.

As usual, we should take care of this possibility. When we do a complete load, QlikView deletes all previous data and reload the data according to the script. In case of partial reload, QlikView does not delete the data but it will add the new data according to the script: therefore, you must be sure that you do not load any data that had already been loaded during the complete load.

Some keywords or functions will help us distinguish a partial to a complete load.

Only: a qualifier denoting that the command is to be done only during partial loads. The command will therefore be disregarded during normal (complete) loads.

IsPartialReload(): Boolean function returning TRUE (-1) if it is a partial reload.

ONLY LOAD …. :   The data will be read only in case of partial reload, disregarded  during complete load

REPLACE ONLY LOAD …. The replace keyword forces QlikView to drop the table before reading the file. In the case of partial reload, QV drops the table and load the data. In case of complete load, QV disregards the whole command (no table dropped, no data read)

Partial Load:

Add: Add is prefix for Load, Select and Map statements. "Add load" statement will execute at normal & partial load. But "Add only load" statement executes only at partial load. It will not check for any duplicates at normal load, but it will checks at partial load

Replace: Replace will replace the previous loaded table and adds the new table with data. It will work at normal and partial load. In normal reload it will load the first table and immediately it will drop the first table, then it will load the replace table along with data. In partial reload it will drop the first table and loads the replace table along with data.  Eg:  If you have data

 

Persons:

Name	Number
Jagan	1
Sri	2

 

New Persons:

Name	Number
Jagan	1
Sri	2
X	3
Y	4

 

Table1:

LOAD

    Name,

    Number

FROM  TestPartial.xlsx (ooxml, embedded labels, table is Persons);

/* This statement works at normal reload and partial reload */

Add

LOAD Name,

    Number

FROM  TestPartial.xlsx (ooxml, embedded labels, table is newPersons);

// This statement works at partial reload

Add Only

LOAD Name,

    Number

FROM

TestPartial xlsx (ooxml, embedded labels, table is NewPersons)

Where not Exists(Name);

Try to comment each statement one by one and check with reload and partial reload based on example