Forum Discussion
Performance Issue - Really Slow While Developing, probable datasource issue
Hi there
If you are using a date table with relationships, I would suggest the following to hopefully improve performance.
Complete all the column modifications in the Power Query Editor. This will ensure that the data is persisted once it is loaded into the data model once only. It is also easier to do the conversions in the Power Query Editor.
Next go into the Options and settings and then Options for your PBIX and make sure to DESLECT Auto Date/Time and Allow data preview to download on background
The first one can make your model really large for every date or date/time column.
The second one will stop data being refreshed in the background, which can also really slow down your model.
Hi Anonymous
Is your dataset very large?
First, please read power bi performance tips to know what would slow your performance and how to avoid it.
Second, If measures could also meet your requirements, you could create measures instead.
Calculated Columns vs Measures in DAX
In your scenario,
my fact table wasn't joining to my date dimension table because the fact tables date time wasn't matching up with the dimensions date due to the time element.
From above, i can conclude:
the key column to join fact table and date table is the "date" coulmn.
in fact table "date" column is of datetime type, while "date" column in the date table is of date type.
To solve above,
You could duplicate "date" column(of datetime type) in the fact table,
then click on "Modelling"->"Data type", select "date". Then this column would be date type.
after this, create relationships between fact table and date table.
Or you could just duplicate "date" column(of date type) in the date table and transform it to "datetime" type.
Best Regards
Maggie
Hi there
If you are using a date table with relationships, I would suggest the following to hopefully improve performance.
Complete all the column modifications in the Power Query Editor. This will ensure that the data is persisted once it is loaded into the data model once only. It is also easier to do the conversions in the Power Query Editor.
Next go into the Options and settings and then Options for your PBIX and make sure to DESLECT Auto Date/Time and Allow data preview to download on background
The first one can make your model really large for every date or date/time column.
The second one will stop data being refreshed in the background, which can also really slow down your model.