This chapter explains how to view comparison reports and provides information about the
reports. For more information, see:
Display a Report
Report Descriptions
Use Teradata Visual Explain to compare the execution plans across different QCDs or
across different Teradata Database systems. Teradata Visual Explain creates a number
of reports comparing various attributes of the plans. These reports help identify
the differences in the plans. Attributes with differences are highlighted in the report.
There are two methods for comparing reports:
1
Compare the response time or join plans of queries:
On systems with different configurations
Across two different Teradata Database releases
With changing demographics
By adding an index and dropping an existing index
2
Compare reports of two plans using either:
An online comparison of any two plans opened in the Teradata Visual Explain interface.
To learn how to select plans for textual comparison, see “Textual Comparison” on page 125.
The comparison reports of a previous bulk compare operation.
To generate the comparison, double-click on a cell in the Bulk Compare report viewer.
The following textual reports can be generated:
Complete Information Report
Teradata Database Configuration Report
Step Information Report (method 2)
Estimated Cost Report (method 1)
Operation Report
Operands Report (method 1)
Residual Condition Report
Join Condition Report
Join Order Report
Source Attributes Report (method 2)
Target Attributes Report
Indexes Used Report
Index Condition Report
Each report provides information on the base query and current query.
A base query is the query against which the current query is compared:
If the report is opened through online comparison of plans, the base query is the
one that is selected in the first row under Selected Execution Plans.
For more information on selecting a base query, see “Textual Comparison” on page 125.
If the report is opened through the Bulk Compare report viewer, the base query is
available in the first column.
The current query is the query selected for comparison against the base query.
If the report is opened through online comparison of plans, the current query is the
one that is selected in a row other than the base query under Selected Execution Plans.
For more information on selecting a current (or compare) query, see “Textual Comparison” on page 125.
If the report is opened through the Bulk Compare report viewer, the current query
is available in the cell that is double-clicked.