Using the Query Governor

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

Table 1-10 shows the data selection options you can set.

Table 1-10: Query Governor data selection options

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 Table 1-11 specify rows retrieved and maximum time on the client, not the server.

Table 1-11: Query Governor data retrieval options

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

NoteUsing 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.