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.
Table 1-10 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. |
The data retrieval settings shown in Table 1-11 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 |