topic Re: Performance issue - Select query takes long time in QlikView

Performance issue - Select query takes long time

raajaswin — Fri, 17 Aug 2018 08:17:13 GMT

Hi All,

I am having a Table with 40 columns and 28 Million Records. I am just doing a select * from that Table it takes 16 Minutes to load. Do we have any idea to further reduce this time?

Re: Performance issue - Select query takes long time

marcus_sommer — Fri, 17 Aug 2018 11:05:36 GMT

Do you really need all columns and records from this table? If only the needed data are queried and transferred it might significantly reduce the run-times. Are after this the run-times yet too long you need to apply an incremental loading. Within the last two link-areas in this document: Advanced topics for creating a qlik datamodel you will find various examples how it could be done.

- Marcus

Re: Performance issue - Select query takes long time

PabloTrevisan — Fri, 17 Aug 2018 12:12:01 GMT

Hi Aswin !

Using select * is never a good practice, I suggest you, start by filtering into the LOAD only the required fields, and then use the WHERE clause to limit the number of records in the table to be read.

Re: Performance issue - Select query takes long time

raajaswin — Mon, 20 Aug 2018 14:07:49 GMT

We need All columns and record as well.

Re: Performance issue - Select query takes long time

PabloTrevisan — Mon, 20 Aug 2018 14:14:37 GMT

you can ask the DBA to create index in the table, or if there is a possibility to parallelize the job in the database. Oracle I already did ..