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Getting Started with Checks

A check applies a rule type to a table or a file. The rule type decides what is asserted: a boundary on a number, the shape of a text value, a relationship between two datasets, the structure of the container itself. Everything else on a check, the filter, the coverage, the ownership, and the metadata, works the same way whichever rule you pick.

This page groups every rule type by the question it answers, so you can find the right one without reading all of them. Each rule has its own section with the full reference, examples, how-tos, and API.

Not sure which rule to pick?

Start from the question you want answered, not from the field. "Is this value inside a range" leads to a different rule than "do these two tables agree", even when both look at the same column.

Numbers and ranges

Rules that constrain a numeric value against a boundary, a range, or another column.

  • Between


    Asserts that values are equal to or between two numbers.

    Between

  • Greater Than


    Asserts that the field is a number greater than (or equal to) a value.

    Greater Than

  • Greater Than Field


    Asserts that this field is greater than another field.

    Greater Than Field

  • Less Than


    Asserts that the field is a number less than (or equal to) a value.

    Less Than

  • Less Than Field


    Asserts that this field is less than another field.

    Less Than Field

  • Max Value


    Asserts that a field has a maximum value.

    Max Value

  • Min Value


    Asserts that a field has a minimum value.

    Min Value

  • Positive


    Asserts that this is a positive number.

    Positive

  • Not Negative


    Asserts that this is a non-negative number.

    Not Negative

  • Equal To


    Asserts that all of the selected fields equal a value.

    Equal To

  • Equal To Field


    Asserts that this field is equal to another field.

    Equal To Field

  • Sum


    Asserts that the sum of a field is a specific amount.

    Sum


Text and format

Rules that validate the shape or the content of a text value.

  • Matches Pattern


    Asserts that a field must match a pattern.

    Matches Pattern

  • Max Length


    Asserts that a string has a maximum length. On array fields, checks the array has at most N elements. With element context, checks each string element's length.

    Max Length

  • Min Length


    Asserts that a string has a minimum length. On array fields, checks the array has at least N elements. With element context, checks each string element's length.

    Min Length

  • Is Type


    Asserts that the data is of a specific type.

    Is Type

  • Is Address


    Asserts that the values are addresses of the required format.

    Is Address

  • Is Credit Card


    Asserts that the values are credit card numbers.

    Is Credit Card

  • Contains Credit Card


    Asserts that the values contain a credit card number.

    Contains Credit Card

  • Contains Email


    Asserts that the values contain email addresses.

    Contains Email

  • Contains Social Security Number


    Asserts that the values contain social security numbers.

    Contains Social Security Number

  • Contains Url


    Asserts that the values contain valid URLs.

    Contains Url


Dates and time

Rules that place a value on the timeline, or watch how recent the data is.

  • After Date Time


    Asserts that the field is a timestamp later than a specific date and time.

    After Date Time

  • Before Date Time


    Asserts that the field is a timestamp earlier than a specific date and time.

    Before Date Time

  • Between Times


    Asserts that values are equal to or between two dates or times.

    Between Times

  • Not Future


    Asserts that the field's value is not in the future.

    Not Future

  • Freshness


    Asserts that the data was added or updated within a maximum allowed age.

    Freshness

  • Time Distribution Size


    Asserts that the count of records for each interval of a timestamp is between two numbers.

    Time Distribution Size


Completeness and uniqueness

Rules about values being present, distinct, or drawn from an agreed set.

  • Not Null


    Asserts that the field's values are not null. On array fields with element context, asserts that no elements within the array are null.

    Not Null

  • Not Empty


    Asserts that a text or array field is not empty. A value made only of spaces counts as empty.

    Not Empty

  • Any Not Null


    Asserts that at least one of the selected fields must hold a value.

    Any Not Null

  • Unique


    Asserts that each field's value is unique across rows. When multiple fields are selected, asserts that the combination of values across those fields is unique (composite key).

    Unique

  • Distinct Count


    Asserts on the approximate count distinct of the given column.

    Distinct Count

  • Expected Values


    Asserts that values are contained within a list of expected values.

    Expected Values

  • Required Values


    Asserts that all of the defined values must be present at least once within a field.

    Required Values


Comparing two datasets

Rules that read a second container and assert a relationship between the two.

  • Data Diff


    Asserts that the dataset created by the targeted field(s) has differences compared to the referred field(s).

    Data Diff

  • Aggregation Comparison


    Verifies that the specified comparison operator evaluates true when applied to the two aggregation expressions.

    Aggregation Comparison

  • Exists In


    Asserts that values assigned to this field exist as values in another field.

    Exists In

  • Not Exists In


    Asserts that values assigned to this field do not exist as values in another field.

    Not Exists In

  • Entity Resolution


    Asserts that records describing the same entity are clustered together, even when their values vary, and that every record in a cluster shares one value of a chosen distinction field.

    Entity Resolution


Structure and volume

Rules that look at the shape of the container rather than at the values inside it.

  • Expected Schema


    Asserts that all selected fields are present and that all declared data types match expectations.

    Expected Schema

  • Field Count


    Asserts that there must be exactly a specified number of fields.

    Field Count

  • Max Partition Size


    Asserts the maximum number of records that should be loaded from each file or table partition.

    Max Partition Size

  • Min Partition Size


    Asserts the minimum number of records that should be loaded from each file or table partition.

    Min Partition Size

  • Volumetric


    Asserts that the volume of the data asset has not changed by more than an inclusive percentage amount for the prescribed moving daily average.

    Volumetric

  • Metric


    Records the value of the selected field during each scan operation and asserts limits based upon an expected change or absolute range (inclusive).

    Metric


Custom logic

Rules where you supply the expression or let the platform learn the expectation.

  • Satisfies Expression


    Evaluates a SQL expression you provide against every record.

    Satisfies Expression

  • Predicted By


    Asserts that the actual value of a field falls within an expected predicted range.

    Predicted By


Deprecated rule types

These rule types still evaluate on existing checks, but they are no longer maintained and should not be used for new ones.

  • Is Replica Of


    Replaced by Data Diff, which performs the same row-by-row comparison and adds change-type filtering.

    Is Replica Of