RAD Studio VCL Reference
TADOConnection.CursorLocation Property

Specifies whether cursors for the connection is client-side or server-side.

property CursorLocation: TCursorLocation;
__property TCursorLocation CursorLocation;

Use CursorLocation to indicate whether the cursors that use the connection object to connect to the ADO datastore use a client-side or server-side cursor library. CursorLocation only affects connections opened after the property is set. The default value for CursorLocation is clUseClient. 

A client-side cursor offers more flexibility. All data is retrieved to the local machine and then operated on there, allowing operations not normally supported by servers like sorting and resorting the data and additional filtering. SQL statements are executed at the server, so for statements that restrict the result set with a WHERE clause, only the reduced result set is retrieved to a local cursor. 

A server-side cursor offers less flexibility, but may be more advantageous (or necessary) for large result sets. Using a server-side cursor becomes necessary when the sheer size of a result set exceeds the available disk space that would be needed to create the client-side cursor. Also, many servers only support unidirectional cursors. This would preclude moving the record pointer in the dataset backward (even one record) through the result set. 


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