The Query Governor lets you set data selection and retrieval options for InfoMaker. Then, when you select and retrieve data, the Query Governor limits that you set apply.
Data selection options
The following table shows the data selection options you can set.
|
Data selection options |
Description |
|---|---|
|
Specify the maximum number of tables in a join |
Specifying a maximum limits data selection. Increasing the maximum means fewer restrictions on data selection and longer retrieval times. |
|
Allow cross products |
When cross products are allowed, you can have tables not joined by the join operator. One row is retrieved for each combination of rows in the tables. If table A has x rows and table B has y rows, a cross product of A and B has x times y rows, unless you specify WHERE criteria. |
|
Allow outer joins |
When outer joins are allowed, all rows in a table are retrieved whether or not a matching row exists in another table. |
|
Allow SELECT DISTINCT statements |
Usually a SELECT statement retrieves all rows satisfying the SELECT statement. If SELECT DISTINCT is specified, duplicate rows are not retrieved. Retrieval time is often much longer when DISTINCT is specified. |
Data retrieval options
The data retrieval settings shown in the following table specify rows retrieved and maximum time on the client, not the server.
|
Data retrieval options |
Description |
|---|---|
|
Specify the maximum number of rows retrieved |
With no maximum set, all rows are retrieved. Specifying a maximum number limits retrieval and means shorter retrieval times |
|
Specify the maximum time for retrieval |
With no maximum set, retrieval time is not limited. Specifying a maximum time limits retrieval time |
Using a shared InfoMaker initialization file
In some organizations, Query Governor options are specified in a shared InfoMaker initialization file. For information about using a shared initialization file, see Connecting to Your Database.
The Query Governor button is not in the PowerBar when you install InfoMaker.
To access the Query Governor from the PowerBar:
-
Customize the PowerBar to add the Query Governor button.
For information about customizing toolbars, see Customizing toolbars.
-
Click the Query Governor button in the PowerBar.
When you select and retrieve data, the default Query Governor options limit you in the following ways:
|
You can do this |
You cannot do this |
|---|---|
|
Join an unlimited number of tables |
Specify cross products |
|
Retrieve an unlimited number of rows |
Specify outer joins |
|
Retrieve for an unlimited time |
Use SELECT DISTINCT statements |
You can change the Query Governor default options at any time by selecting or deselecting the options in the Query Governor dialog box. If you are in the Select painter when you change a data selection option, the change is not enabled until you leave the Select painter and open it again.
