Resident load and precedding load

[#1]

Hi,

can any body expalin the situation resident load is prefered than preceeding load

regards

Mahesh

[Michiel_QV_Fan]

Resident load is also used to reuse already in-memory loaded tables. Preload is used to add dimensions and facts to the current table.

[#3]

yes u r answer is good can u pls give me examples for both

regrds

Mahesht

[jagan]

Hi Mahesh,

Resident Load and Precedent load both are different concepts. 

With Resident load you can load the same table any N number of times again and again.  But with preceding load you can only load one time.  Mainly this is been used in transformation, Calculation, using Qlikview functions with Select query etc.

Example:

LOAD

*,

Year(Transaction_Id) AS Year,

MonthName(Transaction_Id) AS MonthYear,

Week(Transaction_Id) AS Week;

SELECT

Transaction_Id,

Transaction_date

FROM Transaction;

Hope this helps you.

Regards,

Jagan.

[#5]

hi Jagan,

with preceding load also i think more than once table will be loaded let me know where exactly resident load is better use performance wise even in qlikview.

i think instead of creating  table two times in resident load it is better to use preceeding simply it follows load is precedded by sql.

regards

Mahesh

[jagan · Accepted solution]

Hi,

With Preceding it is possible to reload again and again into the same table, it is not possible to create multiple tables with Preceding reload.

Resident Load:

Temp:

LOAD

*

FROM Data;

Temp1:

LOAD

*

FROM Temp;

Temp2:

LOAD

*

FROM Temp;

But with preceding load

LOAD

*,

If(Previous(MonthYear) <> MonthYear, 1, 0) AS MonthStartFlag;   // Second preceding reload

LOAD

*,

Year(Transaction_Id) AS Year,

MonthName(Transaction_Id) AS MonthYear,

Week(Transaction_Id) AS Week;    // First preceding reload

SELECT

Transaction_Id,

Transaction_date

FROM Transaction;

If you are able to manage with preceding load, then it is better than Resident reload.

Hope this helps you.

Regards,

Jagan.

[#7]

Hi Mahesh,

   The result of resident and Preceding load is same. The only difference is way of writing the code.

For example Table1 is having three fields and Table2 having two fields. Want to some transformation between the Table1.Field and Table2.First you want to join both the tables using primary key and then the resultant table will be there in memory now you want do transformation on top of that data,want load the data from memory in that case you can use resident/preceding load.

Syntax for resident:

_Tab:

Load

     A,B,C

From Table1;

Join

Load

A,D

from Table2;

Tab:

Load

     *,

     B+D As E

Resident _Tab;

Drop Table _Tab;

Syntax For Preceding Load:

Tab:

Load

     *,

B+D As E;

Load

     A,B,C

From Table1;

Join

Load

A,D

from Table2;

[#8]

It is fine but i want like preceeding performance is good so why we nedd resident we can avoid but is resident may be useful in some scenariou better than preceeding i want that

regards

Mahesh

[#9]

Hi jagan,

excellent answer from u.if possible give some scenariou

regards

Mahesh

[jagan]

Hi,

Check this

Preceding Load

Regards,

Jagan.