I’ve been successfully using manual load on demand in WebHierarchicalDataGrid for a while now, but recently noticed strange thing. The deeper in grid’s hierarchy I expanded the children – the slower it went.

In my case every time user clicks [+] to expand a row, VB.NET code calls an SQL Server Stored procedure to bring in child rows. I grew suspicious and fired up SQL Profiler. What I saw surprised me. Number of calls to the stored procedure increased the deeper in grid’s hierarchy I expanded the children. When I clicked [+] on the root level it resulted in 1 SP call. Clicking [+] on the child to expand grandchild – 2 calls. Expanding grandchild to see grand-grandchild rows – 3 calls, etc. Continue reading →