Select the Query Options command, select the concurrency strategy option from the Report menu. The Report Query Options dialog, shown in the following image, is then displayed.
The Options sheet is selected by default. The Types tab is enabled only when the report uses database fields from collections within the report root collections or view joins.
From the Concurrency Strategy list box, select the concurrency strategy option that is used to isolate objects from the effects of other transactions during the query process.
The initial value is set from the view on which the current report is based. For details about setting a default concurrency strategy for views, see "Creating a New Reporting View", in Chapter 3.
The following table lists the concurrency strategies available from the Concurrency Strategy list box. The locks are held during the query evaluation phase.
If automatic cache coherency is set in the report node, the object resynchronization is not done, as the objects in the persistent cache are kept up to date.
| Concurrency Strategy | Description |
|---|---|
| None | Does no explicit resynchronization or locking |
| Read Committed | Resynchronizes every object accessed, share locks collections |
| Repeatable Read Optimistic | Resynchronizes every object accessed, share locks collections and objects included in the report output |
| Repeatable Read Pessimistic | Share locks all objects accessed during report output |
From the Resource Limit list box, select a resource limit option for which a matching limit value is to be set, if required. The default value of None indicates that no limits are applied.
If you select a resource limit other than None, a corresponding Limit Value control is displayed, enabling you to set a value for that limit. You must enter this limit as an integer value (that is, a positive whole number), except for the time limit, which is a value in hours and minutes. For example, if you select the Objects Read option, the Limit Value text box enables you to enter a value for the maximum number of objects to be read from the database when the report is run.
The Resource Limit options and corresponding Limit Value values are listed in the following table.
| Resource Limit Option | Limit Value |
|---|---|
| None | Not applicable (that is, ignored), which is the default value |
| Objects Read | Maximum number of objects to read |
| Query Operations | Maximum number of query operations |
| Query Result Objects | Maximum number of result objects to add |
| Run Time | Maximum time in hours and minutes that the report query runs |
Click the OK button. Alternatively, click the Type tab to set reporting options for collections within the report root collections of view joins or click the Cancel button to abandon your selections and close the dialog.
