Data Modelling and Schema Drift Monitoring in Nexalytica

Raw tables are a starting point — a data model is how you shape them into something every analyst, dashboard, and agent can reason about the same way. Nexalytica’s Data Modelling tools let you describe how a source’s tables relate to each other and what its columns mean, so joins and definitions are captured once instead of everyone rediscovering them. Schema Drift monitoring watches for upstream structural changes and routes alerts to the right people before anything breaks.

Data Modelling is labelled Beta. Behaviour and UI controls may change between releases.

Each data source has one model, and it is created for you automatically — there is no gallery of models to manage and no “New model” step. The model is always ephemeral: it lives as a definition only, and Nexalytica queries your source live (federated) rather than copying your data onto its own infrastructure. For that reason there is no “materialize” step and no choice of storage type.

Getting there

Open a data source, go to its Schema tab (the Schema Explorer), and click Open Data Modelling UI. Nexalytica opens the source’s model straight away (creating it the first time). A Back to Schema Explorer link returns you to the plain table/column browser. You can also reach the same surface directly from the Data Modelling route for a source.

Schema Explorer

The starting point is the read-only Schema Explorer. Nothing here modifies your source data — it’s for inspection before (or after) you describe relationships.

Panel	Contents
Left — Table list	All tables in the connected source, with row counts and column counts
Right — Column detail	Column names, data types, and live sample rows for the selected table

Inside the model editor

The editor is a three-part workspace: an Entities / Suggestions sidebar on the left, a canvas in the middle, and a Properties panel on the right.

Control / Button	What it does
Entities list (left)	The physical tables on this source. Click one to drop it onto the canvas as a box.
Suggestions list (left)	AI-proposed relationships between the tables on your canvas, each shown as a card.
Apply all (Suggestions)	Accepts every pending suggestion at once.
Refresh (Suggestions)	Re-runs the suggestion engine to propose relationships for the tables you’ve added.
Per-suggestion ✓ / ✗	Accept or discard a single proposed relationship.
Canvas	The working area: tables are boxes, relationships are lines between them. Drag tables to arrange them, and draw a line between two tables to create a relationship.
Zoom in / Zoom out / Fit view (canvas toolbar)	Navigate the canvas.
Description (Properties → Model Properties)	A free-text description of the model; this feeds the agent’s understanding of the data.
Relationships list (Properties)	The relationships currently in the model, with the option to select or delete each one.
Save Model	Saves your changes (entities, relationships, and description). Stays disabled until there are unsaved edits; prompts you to confirm before discarding unsaved work if you leave.

There is no separate step to publish or store the model — saving is all that’s needed, and the source is queried live whenever an agent, dashboard, or chat uses it.

Schema Drift

Schema Drift monitors your connected sources for structural changes — dropped columns, renamed tables, changed data types — and surfaces them as alerts before downstream models and dashboards break.

Alert anatomy

Each drift alert records:

Field	Description
Severity	`Info` · `Warning` · `Critical`
First detected	Timestamp when the change was first observed
Times seen	How many consecutive sync checks have confirmed the change
Before / After	Structured comparison of the previous and current structure

Triage alerts

Open Alerts
History
Snapshots
Policy

The active triage queue. Every unresolved alert appears here.

Action	How to trigger	Effect
View	Click the alert row or the View button	Opens the structured detail: tables/columns added, removed, or changed, and any primary-key changes
View snapshot diff	Button inside alert detail	Side-by-side comparison of the captured structure before and after the change
Acknowledge	Acknowledge button (available when status is Open)	Marks the alert as seen. You can add an optional note. Logged to the audit trail.
Resolve	Resolve button	Closes the alert. Logged to the audit trail.

Alert statuses

Status	Meaning
Open	Newly detected; awaiting triage
Acknowledged	Seen and noted; not yet resolved
Resolved	Closed by a reviewer
Auto-resolved	Automatically closed when the source structure returned to its previous state

Drift Policy

The Drift Policy tab controls who gets notified and under what conditions.

Control	Options
Recipients	Source owner · Creator · Department admins · Org admins
Custom emails	Additional recipients outside the role list
Severity threshold	`Info` — notify on every structural change · `Warning` — skip minor additions, notify on significant changes · `Critical` — notify only on breaking changes such as dropped columns or renamed tables
Quiet hours	Defer notifications during a specified time window; set the timezone to match your team

Click Save to apply changes or Reset to revert to the last saved state.

If no recipients are selected, drift is still recorded and visible in the Open Alerts tab — but no email notifications are sent. The policy form displays a warning when you save with no recipients configured.

Permissions reference

Owners and Editors

Curate the source’s model — add tables, draw and edit relationships, write the model description
Accept or dismiss AI-suggested relationships
Acknowledge and resolve drift alerts
Configure the Drift Policy

Viewers

Browse the Schema Explorer (read-only)
Open and inspect the model (read-only; no editing)
Review alerts and History tab (read-only; no acknowledge or resolve)

Get Started

Core Concepts

Working with Data

Chats & Dashboards

AI Agents

Data Modelling and Schema Drift Monitoring in Nexalytica

Getting there

Schema Explorer

Inside the model editor

Schema Drift

Alert anatomy

Triage alerts

Alert statuses

Drift Policy

Permissions reference

​Getting there

​Schema Explorer

​Inside the model editor

​Schema Drift

​Alert anatomy

​Triage alerts

​Alert statuses

​Drift Policy

​Permissions reference

Getting there

Schema Explorer

Inside the model editor

Schema Drift

Alert anatomy

Triage alerts

Alert statuses

Drift Policy

Permissions reference