Which data snapshot should I use?
- Brandi Belleau
Several Tableau Data Sources maintain multiple snapshots of data. Within this documentation, we describe why snapshots exist and how they should be used.
What is a Data Snapshot?
The Data Warehouse manages multiple Data Snapshots to lock data in a specific point-in-time, so that you can look at what the system contained as of a specific date. There are any number of reasons why people may need specific data snapshot information, for example:
Institutional reporting may require we report data “as of the term census” or another specific date;
Admissions teams may want to conduct year-over-year comparisons of a comparable point-in-time (e.g., as of halfway through admissions season).
If you’re using a Tableau Data Source that includes multiple data snapshots, you must use filter for a specific snapshot. If you don’t, you will (knowingly or unknowingly) return duplicate records.
How do I know which snapshot I should use?
For most reporting use cases, we would recommend using the current snapshot, which is usually denoted as Most Recent Data. These snapshots should reflect the state of records in the source system as of the last business day. Other snapshots are described in context in the specific Tableau Data Source where they are offered.
Note that the term Most Recent Data refers to the state of the data itself and not to the question of who is counted. For example, if you apply the Most Recent Data flag in the Student Enrollment data source, you’ll see enrollment across all terms in PeopleSoft (and not just the current term).
Which data sources have snapshots?
Data Source | Snapshots available | SQL Definition |
|---|---|---|
Class Schedule | Most Recent Data ONLY | None Needed |
Active Student | Most Recent Data ONLY | None Needed |
Student Enrollment | Most Recent Data |
|
Term Census (as of Sept 28, Feb 4, and July 15 of each year) |
| |
Enrollment and Forecasts | Most Recent Data |
|
Term Census (as of Sept 28, Feb 4, and July 15 of each year) |
| |
Month-end Snapshots (capturing the last day of each month) |
| |
Class Enrollment and Grades | Most Recent Data ONLY |
|
Admissions (Grad/Undergrad) | Most Recent Data |
|
Term Census (as of Sept 28, Feb 4, and July 1 of each year) |
| |
YoY snapshots for the current + prior 2 Fall Terms | CALENDAR_KEY = SYS_CONTEXT
('G$CONTEXT',
'adm_calendar_key_curr') OR
CALENDAR_KEY = SYS_CONTEXT
('G$CONTEXT',
'adm_calendar_key_prev1') OR
CALENDAR_KEY = SYS_CONTEXT
('G$CONTEXT',
'adm_calendar_key_prev2') | |
Graduation | Most Recent Data |
|
Annual Census (i.e., as of July 15 each year) |
| |
Persistence and Graduation | Most Recent Fall Census Date Only (Sept. 28) |
|
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