Relational Load
With the relational load, data is written to a relational database system. The relational load writes data with batch inserts, which groups statements to limit round trips to the database.
Settings
Data source | Extract or transform containing the data to be written. | |||||||||
Tree format | If the data source is a tree, the hierarchy format must be entered. See Overview of Tree Formats. | |||||||||
Target connection | Connection to relational database. Systems currently supported are Apache Derby, H2, HSQLDB, MS Access, MS SQL Server, My SQL, PostgreSQL, and Oracle. | |||||||||
Schema | Not all relational database systems support schemas (e.g. My SQL). | |||||||||
Table | If the database table does not yet exist in the target system, it will automatically be created during the load. | |||||||||
Mode | Note: in the table below, CREATE, INSERT, etc. refer to the instructions to the relational databases and not to the load modes. These were selected with a view to achieving the greatest possible analogy to the cube load. | |||||||||
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Aggregation | This parameter defines the aggregation behavior during the data load. | |||||||||
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If aggregation is active, the aggregation settings define the aggregation level for the columns in the source.
Each field with update mode “key” is a key for the aggregation (not necessarily a primary key in the database table). For the non-key fields, the aggregation function can be set in the update mode. Possible values are: avg, count, first, last, max, min, sum. With update mode "last", a relational UPDATE can be achieved. There is a slight difference between the load modes "add" and "insert": if a numerical column is not specified in the aggregation settings, the default update mode is different. In case of "add", it is "sum"; in case of "insert", it is "last". This makes the relational load modes compatible with the behavior of Cube Load, especially with drillthrough. |
Notes
- In order to determine the data types of the columns and other settings of the database table, the table must first be created directly in the database system.
- It is not possible to run several relational loads for the database table in parallel jobs.
- Load type RelationalSQL should be used for stored procedures, which change data.
Example:
Source: | Existing relational Table: | |||
Customer: A B B C |
Value: 10 20 30 40 |
Customer: C |
Value: 5 |
Results:
Mode ADD, Aggregation=true (Customer: Key, Update Mode: sum) |
Mode ADD, Aggregation=false | ||
Customer: A B C |
Value: 10 50 45 |
Customer: A B B C C |
Value: 10 20 30 40 5 |
Mode ADD, Aggregation=true (Customer: Key, Update Mode: last) |
Mode UPDATE, Aggregation=false |
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Customer: A B C |
Value: 10 30 40 |
Customer: A B B C |
Value: 10 20 30 40 |
Mode UPDATE, Aggregation=true (Customer: Key, Update Mode: sum) |
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Customer: A B C |
Value: 10 50 40 |
Updated September 27, 2022