Snapshot Reporting in the Data Warehouse

Overview

The Data Warehouse supports both live operational reporting and historical replay through effective-dated CDM views.

To support consistent month-end and period-end reporting, a lightweight Snapshot Reporting approach is being introduced.

This allows the business to:

  • reproduce reporting positions retrospectively
  • support finance and PMO reporting consistency
  • preserve confidence in trend reporting
  • distinguish between live operational data and certified reporting outputs

Current reporting challenge

Operational systems are continuously changing.

As projects, people, forecasts, and assignments evolve, live reports may produce different answers when rerun later.

For example:

  • a project status may change retrospectively
  • a resource assignment may be corrected after month-end
  • a forecast value may be updated after reporting close

Without a reporting snapshot approach, it becomes difficult to answer:

“What did the organisation believe at the end of Period 6?”


Existing Data Warehouse capability

The CDM already supports temporal history using:

FieldPurpose
ACTIVE_FLAGCurrent active row
CREATED_DATEDate row became valid
EXPIRED_DATEDate row was superseded

This enables:

  • historical replay
  • trend analysis
  • lifecycle reporting
  • “As At” reporting

The Data Warehouse can therefore reconstruct historical operational truth dynamically.


What is a snapshot?

A snapshot is not a duplicate copy of the entire warehouse.

Instead, a snapshot acts as a:

  • certified reporting reference point
  • period-end reporting context
  • governance control for published reporting

Example:

SNAPSHOT_IDPERIODASAT_DATECREATED
P06_FINAL2026-P062026-03-312026-04-07

This means:

  • the business approved the reporting position for Period 6
  • reports should reconstruct the warehouse state as it existed on 31-Mar-2026
  • the snapshot was formally created on 07-Apr-2026

How snapshot reporting works

Step 1 — Snapshot is selected

A report or process references a snapshot identifier:

P06_FINAL

Step 2 — Snapshot resolves the reporting date

The snapshot identifies the approved reporting date:

ASAT_DATE = 2026-03-31

Step 3 — The warehouse reconstructs the historical state

get.myview automatically runs using:

mode = asat

This reconstructs the operational position that existed at the snapshot date.


Important distinction

Snapshot reporting is not the same as live reporting

Reporting TypePurpose
CurrentLatest operational position
HistoryFull lifecycle and change tracking
As AtReplay operational state on a specific date
SnapshotCertified business reporting position

Benefits of this approach

Consistent reporting

Reports can be rerun later and still produce the same certified reporting position.


Reduced data duplication

The warehouse does not need to create large static copies of all reporting tables every month.


Stronger governance

Snapshots become managed reporting checkpoints rather than uncontrolled spreadsheet extracts.


Preserved operational history

The underlying temporal warehouse remains dynamic and replayable.


Optional approved adjustments

Where necessary, approved overrides or finance adjustments can be stored separately without changing the underlying operational history.


Strategic direction

This approach allows the Data Warehouse to operate as:

  • a live operational reporting platform
  • a historical replay platform
  • a governed reporting certification platform

without reverting to a fully static snapshot-based architecture.

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