Use filters to specify the datapoints to include in the metric calculation for your validator. You can define filters for segmentations on a validator. The following table lists the types of filters that Validio supports:

Filter Types	Description
No Filter	No filter applied to data. Process all available datapoint in a Window.
Boolean Filter	Ensures that a Boolean value is either true or false.
Enum Filter	Ensures that a string only contains values from a fixed set of specified values.
Null Filter	Ensures that a field value is NULL.
String Filter	Ensures that a string adheres to certain criteria.
Threshold filter	Ensures that a numeric value is either under or over a certain threshold.
SQL Filter	Filter records based on a SQL WHERE statement.

For example, to count only the NULL values for a certain field, use a Volume Validator and apply a NULL filter.

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Segmentation Filters
A filter configured on a segmentation will be applied to all validators that use the same segmentation.

Boolean Filter

Filter records based on a boolean field.

Parameter name	Parameter values
Filter type	Boolean filter
Field	List of source fields with Boolean data types
Operator	Is true Is false

Enum Filter

Filter records based on whether field values are part of a defined set.

Parameter name	Parameter values
Field	List of source fields with string data types
Operator	Is in Is not in
Value	List of strings

Null Filter

Filters records on whether a field values are NULL.

Parameter name	Parameter value
Field	List of source fields
Operator	Is Is not

String Filter

Filter records on whether string field values match specific criteria.

Parameter name	Parameter values
Field	List of source fields with string data types
Operator	Is empty Is not empty Contains Does not contain Starts with Ends with Is exactly Regex
Value	String

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Supported Regex Syntax
Depending on source system, Validio leverages different regex syntax:

For Data Warehouses and Query Engines, regex filters are applied in the source system. For more information on that syntax, refer to the regex syntax of your specific source system.

For Object Storages and Data Streams, the regex syntax is compatible with the Rust regex library. For information on that syntax, refer to Rust - regex crate syntax.

Threshold Filter

Filter records on whether numeric values comply to a threshold.

Parameter name	Parameter values
Field	List of source fields with numeric data types
Operator ¹	Equal to Not equal to Greater than Greater than or equal to Less than Less than or equal to
Value	Float number

¹Specifies the 'allowed region'. For example,Greater than or equal to 5 specifies that all values strictly less than five will be filtered.

SQL Filter

You define a SQL filter by typing a valid SQL WHERE statement into the text box, but omitting the word "WHERE". An example of a valid SQL filter is: some_column = 5.

SQL filter works for all Source types, including non-SQL data sources. Different data sources may use different SQL syntax. For more information, refer to the documentation of your data source. For non-SQL data sources, such as Data Streams or Object Storages, you find the supported functionality and syntax in the SQL filter expression reference.

SQL Filter Recipes

The following are recipes for common SQL filters. Each recipe is written in a generic syntax or in syntax specific for Google BigQuery or Snowflake, when required.

You can use these recipes as a starting point when writing SQL filters for other data sources, such as Amazon Redshift or Amazon Athena.

Filter operators

For example,some_column matches a filter with several operators.

some_column IS NULL OR (some_column > 3 AND some_column NOT IN(4,6))

Exists in set

For example,some_column match either of the values 'some_value' or 'some_other_value'.

some_column IN ( 'some_value', 'some_other_value' )

Missing values

For example,some_column is null or matches a value that represents a missing value.

some_column IS NULL OR LOWER(some_column) IN('', '0', '-', 'null')

Semi-structured data

For example,some_array contains at least one element with value 2.

2 IN(SELECT * FROM UNNEST(some_array))

array_contains(2, some_array)

String pattern

For example,some_column does not contain a valid URL.

NOT REGEXP_CONTAINS(some_column, '^(http(s)?:\\/\\/.)?[-a-zA-Z0-9@:%._\\+~#=]{2,256}\\.[a-z]{2,6}\\b([-a-zA-Z0-9@:%_\\+.~#?&//=]*)')

NOT REGEXP_LIKE(some_column, '^(http(s)?:\\/\\/.)?[-a-zA-Z0-9@:%._\\+~#=]{2,256}\\.[a-z]{2,6}\\b([-a-zA-Z0-9@:%_\\+.~#?&//=]*)')