Column data domains, defaults and PII

A data domain is the business type of a column: choosing one sets the column's storage type and its suggested default values. You set the domain, the default value and the PII Domain tag in the Columns step of a table; see Define table columns for the grid itself.

Choose a data domain

Open the table and go to the Columns step.
Click the Data Domain cell of a column.
Pick a domain from the list. The domain fills the Data Type cell with the storage type behind it.
To use a type of your own, pick Custom. Its description reads "You can choose ClickHouse datatype on your own", and Data Type becomes editable.

The picker groups the domains into six categories: Basic Types, Time Types, Identifiers, Specialized Types, Arrays and Complex Types and Custom. Around 50 domains are available across the core and extended lists, and each domain comes with suggested default values you can start from.

When you pick Custom, the types offered depend on the engine:

Engine	Data types
PostgreSQL	integer, bigint, float, decimal, boolean, text, varchar, date, timestamp
ClickHouse	Int, Float32, String, FixedString, Date32, Datetime64

The domain catalogue

Domain	Category	Stored as
Text	Basic Types	String
ShortText	Basic Types	FixedString(50)
SingleCharacter	Basic Types	FixedString(1)
Number	Basic Types	Int32
SmallNumber	Basic Types	Int16
LargeNumber	Basic Types	Int64
UnsignedNumber	Basic Types	UInt32
Decimal	Basic Types	Decimal(18,2)
Amount	Basic Types	Decimal64(2)
LargeAmount	Basic Types	Decimal128(2)
HighPrecisionAmount	Basic Types	Decimal(18,6)
Percentage	Basic Types	Decimal(5,2)
Rate	Basic Types	Decimal(10,6)
Probability	Basic Types	Decimal(5,4)
Boolean	Basic Types	Bool
Date	Time Types	Date32
DateTime	Time Types	DateTime
PreciseDateTime	Time Types	DateTime64(3)
Time	Time Types	DateTime64(0)
Year	Time Types	UInt16
Month	Time Types	UInt8
Quarter	Time Types	UInt8
DateRange	Time Types	Tuple(Date, Date)
Duration	Time Types	Int32, seconds
ID	Identifiers	UInt32
LargeID	Identifiers	UInt64
UUID	Identifiers	UUID
ExternalID	Identifiers	String
GeoPoint	Specialized Types	Point
IPAddress	Specialized Types	IPv4
Status	Specialized Types	LowCardinality(String)
CountryCode	Specialized Types	LowCardinality(FixedString(3))
KeyValuePairs	Arrays and Complex Types	Map(String, String)
RelatedList	Arrays and Complex Types	Array(Tuple(String, UInt128))

Amount is described as "For monetary amounts, 2 digits after decimal", and PreciseDateTime keeps millisecond precision.
The catalogue also includes Code (for codes, symbols and identifiers, such as SWIFT or IBAN), Email, URL, PhoneNumber, JSON, Currency (currency codes such as USD, EUR or GEL), Hash, and the list domains TextList, NumberList and DateList.
Suggested defaults include values such as now(), today(), -1 and 0.00.
Identifier domains such as ID, LargeID, UUID and ExternalID suggest generator values: generateUUIDv4(), generateSnowflakeID(), generateShortID() and generateTimeBasedID().

Default values

The Default Value cell holds the value a column takes when no value is given. While you edit it, DataMind suggests values already used by other columns of the same table whose storage type falls in the same group as this column's type. Suggestions skip the column you are editing, skip empty values and remove duplicates.

The groups are Whole Number, Decimal Number, Date, Date/Time, Time, Duration, True/False and Text.
Wrappers and parameters are removed before matching: Nullable(String) matches String, and Decimal(10,2) matches Decimal. UInt32 and UInt64 group as Decimal Number. A type the groups do not cover matches only its exact type.
A column counts as a string column when its type name contains String, as in String, FixedString(50), Nullable(String) or LowCardinality(String). For those columns, the value appears in the cell wrapped in single quotes, with inner quotes doubled.

Tag columns with PII domains

The PII Domain cell marks which kind of personal data a column holds. The choices span eight categories:

Personal Identity
Contact & Location
Financial / PCI
Health / PHI
Government & Tax
Digital Identity
Credentials & Secrets
Sensitive Dates

The catalogue holds 51 options in total, covering names, contact details, card and bank details, health data, government identifiers, credentials and sensitive dates. To clear a tag, choose None. The tag decides what the PII policy treats as personal data for that column; how the platform acts on it is set up on PII detection.

Questions, answered

What is the difference between a data domain and a data type?

A data domain is the business type you recognise, such as Email or Amount. A data type is the storage form behind it, such as String or Decimal64(2). Choosing a domain fills Data Type with the type behind it.

Does choosing a domain change the data type?

Yes. Each domain carries a storage type, and picking the domain fills Data Type with that type. Custom is the exception: it lets you enter the type yourself.

What does Custom mean?

Custom means you choose the storage type yourself instead of taking the type behind a domain. Its description reads "You can choose ClickHouse datatype on your own". The types offered depend on the engine: PostgreSQL offers integer, bigint, float, decimal, boolean, text, varchar, date and timestamp; ClickHouse offers Int, Float32, String, FixedString, Date32 and Datetime64.

Where do the Default Value suggestions come from?

From other columns of the same table: DataMind suggests defaults already used by columns whose storage type falls in the same group as this column's type. Empty values are skipped and duplicates removed; the column you are editing is not used.

Which columns share default value suggestions?

Columns whose types fall in the same group: Whole Number, Decimal Number, Date, Date/Time, Time, Duration, True/False and Text. Wrappers and parameters are stripped before matching, UInt32 and UInt64 count as Decimal Number, and a type outside the groups matches only its exact type.

Why does a suggested default show without quotes, but the saved value has them?

The suggestions show text values without the surrounding quotes. In the cell, the value appears wrapped in single quotes, with inner quotes doubled, and that is how it is stored.

Which domain should I use for a currency code column?

Currency. Its description reads "Currency codes (USD, EUR, GEL)".

How do I remove a column's PII tag?

Choose None in the PII Domain cell. It clears the tag.

What PII categories can I tag a column with?

Eight categories: Personal Identity, Contact & Location, Financial / PCI, Health / PHI, Government & Tax, Digital Identity, Credentials & Secrets and Sensitive Dates.

Does the PII tag change how the platform handles the column?

The tag decides what the PII policy treats as personal data in that column. How the platform acts on personal data is set up on PII detection.