Field Types

Every column in a feature dataset or table has a field type, which tells GOAT how to store the values, how to display them, and which tools can use the column. This page explains the field types GOAT supports.

Spatial Data Storage

GOAT keeps a dataset's metadata separate from the data itself:

• Metadata — the dataset's name, description, field definitions, styling and sharing settings — is held in a PostgreSQL database.
• Data — the geometries and attribute values — is stored in DuckLake, an analytical store built on Parquet files in object storage. This is what lets GOAT query and analyse large datasets quickly.

All geometries are stored in the EPSG:4326 coordinate reference system (longitude and latitude in degrees). Measurements are not taken in degrees, though: Area, Perimeter and Length columns are calculated on the earth's curved surface, so their values are true meters and stay accurate across large areas.

For a fuller picture of how the platform fits together, see Architecture.

Supported Field Types

Field type	What it holds	Examples
Text	Any text	Street names, categories, descriptions
Number	Whole numbers or decimals	1, -5, 3.14, 45.67
Boolean	True or false values	true, false
Date	A point in time	2024-01-15 14:30:00
Area	The surface area of a polygon	1.25 ha, 340 m²
Perimeter	The outline length of a polygon	820 m
Length	The length of a line	1.4 km
Formula	A value calculated from other columns	population / area

Columns you fill in yourself

Text, Number, Boolean and Date hold the values you enter or import. You can add them to a dataset at any time, and they are the types available when you create a new dataset from scratch.

A Number column can be formatted for display. Formatting changes only how the value looks in GOAT — the stored value is untouched, and tools keep using the full number.

Setting	Effect on 1234567.891
Decimals	2 rounds the display to 1234567.89; auto lets GOAT decide
Show thousands separator	1,234,567.891
Abbreviate large numbers	1.2M
Always show sign	+1234567.891, so positive values are as clearly marked as negative ones

The same settings are available on Area, Perimeter and Length columns, which additionally let you pick the Unit the value is shown in — m², ha or km² for Area, and m or km for Perimeter and Length. Leave it on auto and GOAT picks a unit that suits the value.

GOAT shows a live preview as you change these, so you can see the result before saving.

Columns GOAT calculates

Area, Perimeter, Length and Formula are computed: GOAT derives their values and keeps them up to date, so they cannot be edited by hand. They are offered when you edit the fields of an existing dataset — a new dataset has no data for them to be calculated from yet.

Formula can be added to any dataset. The measurement types depend on your dataset's geometry, since not every shape can be measured the same way:

• Polygons — Area and Perimeter
• Lines — Length
• Points — neither, as a point has no extent
• Tables (no geometry) — neither

A Formula column is defined by an expression you write in the Formula builder, and GOAT recalculates it whenever the data it depends on changes.

Restricting what a column accepts

Text and Number columns can carry a list of Allowed values. Everyone editing the dataset then picks from that list instead of typing freely, which keeps categories consistent — no more bus stop, Bus Stop and bus_stop in the same column.

1

In the data table, open the Text or Number column you want to restrict: either click Edit fields and select it from the list, or click the menu on its column header and choose Edit field.

2

Under Allowed values, type a value and press Enter. Repeat for each value you want to allow.

3

Once the list has at least one value, an Allow other values switch appears. Turn it on to treat the list as a suggestion rather than a rule.

4

Click Save.

Leaving the list empty accepts any value, which is how every column starts.

Reserved column names

Some names are used internally by GOAT and cannot be given to a column, among them id, geometry and geom. If you type one, GOAT flags the field straight away and will not let you save until you change it.

How to view field types

GOAT marks each column with a small field type chip: A for Text, 123 for Number, and an icon for the other types. Hover over the chip to see the field type's name.

The chip appears wherever columns are listed — the data table, the field list in layer settings, column filters, and the field pickers in tools and the Formula builder.

To see it in the data table:

1

Click on More Options button on your layer

2

Select View data from the menu

3

In the data table, the field type chip is shown beside each column name

Accessing the View Data option

Field type chips shown beside each column name