Aggregate (In Database)
(In-Database Processing)
Synopsis
Performs an aggregation / GROUP BY operation on the current result.Description
This operator performs the well known GROUP BY operation using the specified list of grouping attributes. It then applies the specified aggregate functions on the selected columns. The aggregate functions can be defined in two different ways: either explicitly in a list, or by using the attribute selector and specifying a default aggregation function for these columns. The two methods can be combined. Note that the known HAVING clause from SQL can be simulated by an additional Filter Examples operator following this one.
Input
example set input
Output
- example set output
Parameters
- use default aggregation If checked you can select a default aggregation function for a subset of the attributes.
- attribute filter type The condition specifies which attributes are selected or affected by this operator.
- attribute The attribute which should be chosen.
- attributes The attribute which should be chosen.
- regular expression A regular expression for the names of the attributes which should be kept.
- use except expression If enabled, an exception to the specified regular expression might be specified. Attributes of matching this will be filtered out, although matching the first expression.
- except regular expression A regular expression for the names of the attributes which should be filtered out although matching the above regular expression.
- value type The value type of the attributes.
- use value type exception If enabled, an exception to the specified value type might be specified. Attributes of this type will be filtered out, although matching the first specified type.
- except value type Except this value type.
- block type The block type of the attributes.
- use block type exception If enabled, an exception to the specified block type might be specified.
- except block type Except this block type.
- numeric condition Parameter string for the condition, e.g. '>= 5'
- invert selection Indicates if only attributes should be accepted which would normally filtered.
- default aggregation function The type of the used aggregation function for all default attributes.
- aggregation attributes The attributes which should be aggregated.
- group by attributes Performs a grouping by the values of the attributes by the selected attributes.