Performing index rebuild in multiple processes while using an application

InterSystems FAQ rubric

You can use the %IndexBuilder class to perform index rebuilding using multiple processes.

Here is an example for the purpose of defining the standard index HomeStateIdx for the Home_State (state information of contact address) column of Sample.Person.

The steps are as follows:

1. Hide the index name to be added/rebuilt from the query optimizer.

>write $system.SQL.SetMapSelectability("Sample.Person","HomeStateIdx",0)
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2. Add %IndexBuilder to the rightmost superclass of the class definition that defines the new index.

///The class definition statement is as follows (add it at the far right)
Class Sample.Person Extends (%Persistent, %Populate, %XML.Adaptor, %Library.IndexBuilder)

3. Register the index name to be rebuilt in the INDEXBUILDERFILTER parameter of the class definition.

Index HomeStateIdx On Home.State;
Parameter INDEXBUILDERFILTER = "HomeStateIdx";

4. Compile the class.
5. Use the %ConstructIndicesParallel() method to rebuild indexes in parallel.

set st=##class(Sample.Person).%ConstructIndicesParallel()

6. After rebuilding the index, expose the added index to the optimizer.

>write $system.SQL.SetMapSelectability("Sample.Person","HomeStateIdx",1)
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Please refer to the following document for details.

How to rebuild the index while the application is running【IRIS】

How to rebuild the index while the application is running