Domain 2 — Data Management (32%)¶

The second-largest domain. Roughly 24 of 75 questions. Heavy on coordinate systems, editing, and geodatabase basics.

What's tested¶

2.1 Coordinate systems and projections¶

This is the subtopic the exam loves.

Two flavors of CRS¶

Datum vs projection¶

• Datum — the model of the earth's shape. Examples: WGS84, NAD83, NAD27.
• Projection — the math that flattens the datum onto a plane. Examples: Mercator, UTM, Lambert, Albers, State Plane.

A PCS = datum + projection + parameters (false easting, central meridian, etc.).

EPSG codes to memorize¶

You will not be asked to recite many codes, but you must recognize 4326 and 3857 as questions phrased "the data is in WGS84" or "the basemap uses Web Mercator."

On-the-fly projection¶

ArcGIS Pro projects layers on display to match the map's CRS (the first layer added sets it by default). The underlying data isn't changed. If you want to permanently reproject, use the Project geoprocessing tool.

Datum transformation¶

When a layer's CRS uses a different datum from the map's CRS, ArcGIS Pro warns you to set a datum transformation (e.g., NAD27 → NAD83). If you skip it, features can shift up to 200 m.

→ Configure on Map Properties → Transformation.

→ See Coordinate Systems & Projections, tutorial.

Common exam patterns¶

• "Why are my features 200m off from a basemap?" → Wrong / missing datum transformation
• "What's the projection used by the World Imagery basemap?" → Web Mercator (EPSG 3857)
• "You add a layer in WGS84 to a NAD83 map. What happens?" → ArcGIS Pro projects on the fly; warns about datum transformation
• "How to permanently reproject?" → Project tool (Data Management → Projections and Transformations → Project)

2.2 Editing workflows¶

ArcGIS Pro uses an edit mode with a Save / Discard workflow.

Steps to create a feature¶

1. Make sure the layer is editable (not a read-only service).
2. Edit ribbon → Create. The Create Features pane opens with edit templates (one per layer + symbology).
3. Click an edit template → choose a construction tool (Point / Polyline / Polygon / Rectangle / Circle, etc.).
4. Click in the map. Use snapping (toggle on the status bar) to align to existing features.
5. Press F2 or double-click to finish the geometry.
6. Edit the attributes in the Create Features pane or Attributes pane.
7. Save edits (or Discard).

Steps to modify a feature¶

• Edit ribbon → Modify Features pane → choose tool (Move, Reshape, Vertices, Split, Merge, Replace Geometry, etc.).
• Or the Attributes pane to change attribute values.
• Save edits.

Snapping¶

The snapping toolbar lets you align to vertex / edge / endpoint / intersection / midpoint / tangent. Toggle in the Edit ribbon → Snapping group.

Common exam patterns¶

• "Why can't I edit this layer?" → Read-only service / no permissions / layer not editable / not in edit session
• "How to align a new feature exactly to an existing one?" → Snapping
• "How to undo edits without saving?" → Discard Edits
• "What pane lists the editable layers and tools?" → Create Features / Modify Features

→ See Attribute Tables.

2.3 Managing tabular data¶

Field types¶

Add Field¶

Fields tab → Add → set name, alias, type, length → Save.

Calculate Field¶

Right-click field → Calculate Field or Geoprocessing → Calculate Field.

• Calculator: Python 3 or Arcade.
• Examples:
  • !POP_TOTAL! / !AREA_SQMI! (Python — population density)
  • $feature.POP_TOTAL / $feature.AREA_SQMI (Arcade)

Join vs Relate¶

→ See Joins & Relates.

Common exam patterns¶

• "Most ACS rows are NULL after the join." → Field type / formatting mismatch
• "How to permanently merge a join?" → Export Features (or right-click table → Export Table)
• "How to enforce one-to-many?" → Use a Relate instead of a Join
• "How to remove a join?" → Right-click layer → Joins and Relates → Remove Join

2.4 Supported data formats¶

Common exam patterns¶

• "What is the recommended format for storing multiple feature classes?" → File geodatabase
• "Why does my shapefile lose attribute names longer than 10 chars?" → Shapefile attribute name limit
• "Format that supports topology, domains, and subtypes?" → Geodatabase (file or enterprise)

2.5 Creating a file geodatabase + feature class¶

Create the FGDB¶

1. In Catalog pane, right-click your project's databases folder (or any folder).
2. New → File Geodatabase.
3. Name it.

Create a feature class inside¶

1. Right-click the FGDB → New → Feature Class.
2. In the wizard:
   • Name & alias.
   • Feature type (Point / Line / Polygon / Multipoint / Annotation).
   • Geometric properties (M values, Z values).
   • Coordinate system — pick the right one for your area.
   • Tolerance / Resolution — usually defaults.
   • Fields — define attribute fields (or add later).
3. Click Finish.

Common exam patterns¶

• "How to create a new geodatabase?" → Catalog → right-click folder → New → File Geodatabase
• "How to add fields when creating a feature class?" → In the Create Feature Class wizard, Fields step (or after creation in the Fields view)

2.6 Metadata¶

ArcGIS Pro supports several metadata styles. The default is Item Description (light). For full metadata, switch the project's metadata style.

Where to access¶

• Catalog pane → right-click item → View Metadata.
• Catalog view → Metadata tab.

What to record¶

• Title, summary, description
• Tags / keywords
• Use limitations and credits
• Spatial extent (often filled automatically)
• Coordinate system (auto)
• Lineage (where this came from)
• Update / publication dates
• Contact

Setting the metadata style¶

Project → Options → Metadata → Metadata style. Choices:

• Item Description (default — light)
• FGDC CSDGM
• ISO 19115
• ISO 19139 Service Information
• INSPIRE Metadata Directive
• North American Profile of ISO 19115

Common exam patterns¶

• "How to change the metadata style for the project?" → Project → Options → Metadata
• "Where to view the spatial extent of a layer?" → Layer Properties → Source, or the metadata
• "Difference between Item Description and ISO?" → Light vs full / formal

→ See Sharing to ArcGIS Online (metadata is also tied to publishing).

Domain quick-quiz¶

1. What's the difference between datum and projection?
2. EPSG 4326 corresponds to which CRS?
3. Why store FIPS codes as text and not number?
4. Which format is recommended for new datasets — Shapefile or File Geodatabase?
5. Where do you set a datum transformation for the map?
6. What pane do you open to edit features?
7. Difference between a join and a relate?

→ Next: Domain 3 — Performing Analysis (20%).