Regarding VARNUM

[SAS_AMUH]

PROC CONTENTs data=demo varnum; run;

I have just used the above code VARNUM for programming for the first time.

I used this because I thought that I could use it to assess if the data was imported accurately. 

For this reason, I checked the Number of observations, variables, and also confirmed that value is 0 for both "Deleted Observations" & "Number of Data Set Repairs". 

Q1. Any other tips for using this varnum code? for any other purposes?

Q2. I am having a bit of difficulty understanding some keywords in this output, especially 

- indexes, observation length, number of data set pages, Max Obs per Page, Obs in First Data Page  (I don't quite get which "page" it is)

Could someone please tell me or suggests a webpage explaining these keywords?

 Thank you for your help in advance.

[Kurt_Bremser · Accepted solution]

SAS datasets are organized in "pages" of equal size. Observations are fit into a page by using the formula int(pagesize/observation length), the remaining space in a page is padded out.

Since the first page also contains the header information with all variable attributes, it has less space for observations.

Observation length is computed by adding up all variable lengths.