Search Returning some empty cells

[evanbonner]

Hi,
I'm pretty new to splunk searches and i am trying to report on successful logins for login types 7, 8, 10 and 11, but always one of my columns are empty depending on the time i pick, and the column is always different,

index=win* AND (EventCode=4624) AND (Logon_Type=7 OR Logon_Type=8 OR Logon_Type=10 OR Logon_Type=11) AND (host="DESKTOP*" OR host="LAPTOP*")
| bucket _time span=1w
| eval username = mvindex(Account_Name,1)
| dedup username consecutive=true
| eval dayTimeStr = strftime(_time,"%Y-%m-%d")
| chart count over username by host

I also pipe the data into a table command just to sort out the data for visual purposes.

0 0 0 0 0 0 N 0 5 0 0
0 0 0 0 0 0 N 0 4 0 0
7 51 0 0 0 0 N 0 0 0 0
0 0 13 0 0 0 N 0 0 0 0
0 0 0 14 0 0 N 0 0 0 0
0 0 0 0 22 0 N 0 0 0 0
0 0 0 0 0 19 N 0 0 0 0
0 0 0 0 0 0 N 4 39 0 0
0 0 0 0 0 0 N 0 0 5 0
0 0 0 0 0 0 N 0 0 0 34

The above is the count given to all users and the N column are null values showing as blank, and when i change the time span the null column switches to another column.

[somesoni2]

Your search gives count events for the users who are logged into a particular host (machine). Now, not all users will log into all machines, so in your cross tables, there will be columns which will have 0 as count. What's the expected output from the search?

[evanbonner]

in the table i have all the computers with all the users for those computers on the same table so i would be expecting all the columns to be mostly Zeros in the column except where the user matches the machine, but the null column shifts across when i change the time range, for example, if i change the time range to 30 days, the neighbor column that had matching data turns to having null and the column that had nulls are showing correctly.