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delphiadodbgrid

DBGrid with read ahead capability using ADO

I'm working with ADO connecting to SQL Server 2005.

My TADODataSet selects 1 million records. using a TDBGrid and setting the TADODataSet.CursorLocation to clUseServer works. but the TDBGrid chokes!

How can I select 1 million records, avoid paging, and still be able to display records in the grid without fetching ALL records to the client side, letting the Grid read ahead as I scroll up and down?

SQL enterprise manager can execute a query and select 1 million records asynchronously without any problems (also MS-ACCESS).

Solution

  • TGrid is not your problem. Your problem is TADODataset is trying to load all the records. If you must run a query that returns so many records, you should set ExecuteOptions, try eoAsyncExecute and eoAsyncFetch. It may also help to set CacheSize.