DESIGNER_SET_ANALYZE_CORRELATIONS_MODE

Specifies how Database Designer handles column correlations in a design. A design's mode determines whether Database Designer analyzes or re-analyzes existing column correlations and considers them in the design that it creates.

The following recommendations apply:

  • You typically need to analyze column correlations only once.

  • Analyze correlations when the table row count is at least DBDCorrelationSampleRowCount—by default, 4000.

Database Designer analyzes column correlations for a design only if you enable analysis with this function.

Behavior Type

Immutable

Syntax

DESIGNER_SET_ANALYZE_CORRELATIONS_MODE ( 'design‑name', mode )

Parameters

design‑name Name of the design that specifies how Database Designer handles correlated columns.
mode

Specifies how to handle correlations in the design tables, one of the following integer settings:

0 Ignore column correlations in the design tables.
1 Consider existing correlations in tables when creating the design. If no existing correlations exist, Database Designer sets none in the design.
2 Analyze column correlations on tables where correlation analysis was not previously performed. When creating the design, consider all column correlations, new and existing.
3 Analyze all tables for column correlations and consider them when creating the design. If correlations already exist for a table, ignore them and re-analyze the table.

Setting the correlation analysis mode does not affect whether Database Designer analyzes statistics when creating a design.

Privileges

One of the following:

  • Superuser
  • DBDUSER role with USAGE privilege on the design schema.

Example

The following example specifies that Database Designer analyze all tables for correlated columns and consider them when creating a design: 

=> SELECT DESIGNER_SET_ANALYZE_CORRELATIONS_MODE ('VMART_DESIGN', 3);
 DESIGNER_SET_ANALYZE_CORRELATIONS_MODE
----------------------------------------
                                      3
(1 row)

See Also