Can Text Keys affect Performance?

[GulianiG]

Hi Experts, 
I came across conflicting information about storing keys for relationship as Text vs Whole Number
I benefit from having it as Text data type because it helps be debug errors easily as the key 

9590.03312021

 is made up of 2 columns (ID & Date)
But I am reluctant to make it such as this will be used in a heavy model so Performance has to be optimal but the trade off of easy debugging also cannot be ignored because the length of ID in key varies above and hence inserting a perid (.) helps separate ID & Date visually

Thanks

[danextian · Accepted solution]

Hi @GulianiG 

I am not sure about data modeling performance but that kind of key will definitely lead to a longer refresh time which may be negligible depending on the data size. Why longer? Because that will cause a higher cardinality and will take a longer time to write  into memory as opposed to having two separate dimensions for ID and Date. Also, a higher cardinality requires more storage. That is why it also a best practice to split a datetime column into date and time columns or just remove the time component if not needed.