If I'm not crazy, I have a whole bunch of index additions I would highly recommend adding to the DNN installed database and before I go too crazy making a complete list I wanted to see if there was someone/somehow to submit these to the team to get implemented. First part of the list is below. I can give the specific procs that would use the index like I did with the first example.

-- supports fk

-- proc GetAffiliate

-- proc GetAffiliates

-- proc DeleteVendor

CREATE NONCLUSTERED INDEX [IX_Affiliates_VendorId]

    ON [dbo].[Affiliates]([VendorId] ASC);

CREATE NONCLUSTERED INDEX [IX_AnonymousUsers_LastActiveDate]

    ON [dbo].[AnonymousUsers]([LastActiveDate] DESC);

CREATE NONCLUSTERED INDEX [IX_AnonymousUsers_PortalID]

    ON [dbo].[AnonymousUsers]([PortalID] ASC);

CREATE NONCLUSTERED INDEX [IX_Assemblies_AssemblyName]

    ON [dbo].[Assemblies]([AssemblyName] ASC);

CREATE NONCLUSTERED INDEX [IX_Assemblies_PackageID]

    ON [dbo].[Assemblies]([PackageID] ASC);

CREATE NONCLUSTERED INDEX [IX_Authentication_AuthenticationType]

    ON [dbo].[Authentication]([AuthenticationType] ASC);

CREATE NONCLUSTERED INDEX [IX_Authentication_IsEnabled]

    ON [dbo].[Authentication]([IsEnabled] ASC);

CREATE NONCLUSTERED INDEX [IX_Authentication_PackageID]

    ON [dbo].[Authentication]([PackageID] ASC);

CREATE NONCLUSTERED INDEX [IX_ContentItems_ContentTypeID]

    ON [dbo].[ContentItems]([ContentTypeID] ASC);

CREATE NONCLUSTERED INDEX [IX_ContentItems_Indexed]

    ON [dbo].[ContentItems]([Indexed] ASC);

CREATE NONCLUSTERED INDEX [IX_ContentItems_ModuleID]

    ON [dbo].[ContentItems]([ModuleID] ASC);

CREATE NONCLUSTERED INDEX [IX_ContentItems_StateID]

    ON [dbo].[ContentItems]([StateID] ASC);

CREATE NONCLUSTERED INDEX [IX_ContentItems_MetaData_ContentItemID]

    ON [dbo].[ContentItems_MetaData]([ContentItemID] ASC);

CREATE NONCLUSTERED INDEX [IX_ContentItems_MetaData_MetaDataID]

    ON [dbo].[ContentItems_MetaData]([MetaDataID] ASC);

CREATE NONCLUSTERED INDEX [IX_ContentWorkflowLogs_ContentItemID]

    ON [dbo].[ContentWorkflowLogs]([ContentItemID] ASC);

CREATE NONCLUSTERED INDEX [IX_ContentWorkflowLogs_WorkflowID]

    ON [dbo].[ContentWorkflowLogs]([WorkflowID] ASC);

CREATE NONCLUSTERED INDEX [IX_ContentWorkflowStatePermission_PermissionID]

    ON [dbo].[ContentWorkflowStatePermission]([PermissionID] ASC);

CREATE NONCLUSTERED INDEX [IX_ContentWorkflowStatePermission_StateID]

    ON [dbo].[ContentWorkflowStatePermission]([StateID] ASC);

CREATE NONCLUSTERED INDEX [IX_ContentWorkflowStatePermission_UserID]

    ON [dbo].[ContentWorkflowStatePermission]([UserID] ASC);

 you can submit any suggested changes via support.dnnsoftware.com , or submit pull requests via https://github.com/dnnsoftware/Dnn.Pl... . Please note, we will require some evidence that the changes are a benefit e.g. http://www.brentozar.com/archive/2012... . This is because whilst indexes are typically desirable in some cases (such as tables with little or no data) they can actually impact performance (and also because it's never a good idea to make a performance optimisation change without measuring if the change improves things first)