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Exporting a very large table box to a tab delimited text file

I want to export the contents of a table box (7 million records x 100 characters) to a text file (to drop into another system).

If I fire up the export command, memory usage rapidly runs up to maximum (11.7gb) at which point CPU usage falls to a trickle.

Why does creating an 800mb text file take 10gb of RAM? If I leave it running how long will it take? Is there a better way of dropping data out of a QVS?

Ralph Lucas

4 Replies
Not applicable
Author

Hi

I can't tell you why the memory usage goes sky high, I'll leave that to someone else to answer...

When you say "drop data" it sounds to me like it's a one time thing??
If it is, maybe you can use the store-command in the load script to create the textfile (store * from myTable into myTextfile.csv (txt)).

/Fredrik

hectorgarcia
Partner - Creator III
Partner - Creator III

I.m not a savy but.. i think waht fredrik is sugesting only works to create QVD files. I tried yo so it in a sample script and generates an unreadable file, ( a combination of XML and special characters)



test:

LOAD

monthname(Fecha) as Fecha

,

[Empresas por Cantidad de Registros en Lote]

,

[Registros en Lote]

,

Grupos

,

[Total Empresas]

,

[Precio Unitario]

,

Facturar

FROM

[..\Datos Modulo de seguriad y Modulo lotes Bole Mercantil 2009.xls] (biff, header is line, embedded labels, table is lotes)

;

store

* from test into myTextfile.csv

(txt);







mike_garcia
Luminary Alumni
Luminary Alumni

I have not used the Store command to create text files, but the help suggests to use the txt file extension:

Store mytable into myfile.txt (txt);


I think it is a good idea to use it. If the table box needs to be created based on selections, maybe you will need to use a where clause when creating the table in the script.

Regards,

Mike.

Miguel García
Qlik Expert, Author and Trainer
Not applicable
Author

Thankyou all for your help.

I had not realised that this facility had been added to QV - my version is without it. I will upgrade to 9 and try.

Ralph