The Quota page on the Optimization tab of the Preferences window allows you to restrict the number of SQL transformations produced during optimization process. The optimization quotas can only be changed when the optimizer intelligence level is set to custom.
The maximum number of SQL statements generated by applying rules in the Feedback-Searching engine. The default quota of 100 is normally sufficient for most of the complicated SQL statements. However you can increase the quota to tackle exceptionally complicated SQL statements with very high levels of table joins or multiple levels of nested sub-queries.
This value controls the number of SQL statements that are generated during the process of rewriting the syntax of the SQL statement.
The maximum number of SQL statements generated by applying the degree of parallelism in the Feedback-Searching engine. Only applicable if the MAXDOP checkbox is selected.
The percentage used to calculate the maximum number of SQL statements to apply forces.
This value determines the number of SQL alternatives that are generated by applying the Forces to the original SQL and the SQL alternatives that were created by transforming the SQL syntax.
A read only field indicating the number of forces selected. Only the forces that have an * after the name on the Forces page are counted. This figure is used to calculate the maximum number of SQL statements generated by applying forces, ((Syntax Transformation Quota + Parallel Quota )* Forces Quota Ratio%)*Number of Forces Selected = Forces Quota.
The maximum number of SQL statements generated during optimization, this figure consists of: Syntax Transformation Quota + Parallel Quota + Forces Quota.
The maximum number of table joins rearrangements to generate a new table join access path during optimization.
Note: You should bear in mind that the higher the quota, the longer it might take to optimize a complicated SQL statement.