PowerExchange for Hive User Guide

PowerExchange for Hive User Guide

Query Properties

Query Properties

The Data Integration Service generates a default SQL query that it uses to read data from the relational resources. The default query is a SELECT statement for each column that it reads from the sources. You can override the default query through the simple or advanced query.
The following table describes the query properties that you configure for relational sources:
Property
Description
Show
Overrides the default query with a simple or advanced query. Use the simple query to select distinct values, enter a source filter, sort ports, or enter a user-defined join. Use the advanced query to create a custom SQL query for reading data from the sources.
Select Distinct
Selects unique values from the source. The Data Integration Service filters out unnecessary data when you use the relational data object in a mapping.
Select Distinct is disabled for columns with hierarchical data types.
Join
User-defined join in a relational data object. A user-defined join specifies the condition used to join data from multiple sources in the same relational data object.
Filter
Filter value in a read operation. The filter specifies the
where
clause of select statement. Use a filter to reduce the number of rows that the Data Integration Service reads from the source. When you enter a source filter, the Developer tool adds a
WHERE
clause to the default query.
Sort
Sorts the rows queried from the source. The Data Integration Service adds the ports to the
ORDER BY
clause in the default query.
You cannot use Sort for columns with hierarchical data types.
Advanced Query
Custom query. Use the advanced query to create a custom SQL query for reading data from the sources.

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