SQL Server Compact
SQL Server Compact 3.5 is supported in the main LightSpeed DLL. SQL Server Compact 4 is supported via the supplementary DLL Mindscape.LightSpeed.Providers.SqlServerCe4.dll. If you are using SQL Server Compact 4, you must deploy this to the same directory as the main LightSpeed DLL.
SQL Server Compact 3.5 does not support paging. Although SQL Server Compact 4 provides some support for paging, this is not comprehensive. Some paging and ordering operations may still fail.
Some string operations (notably concatenations with ToString()) fail on SQL Server Compact.
The coalesce (??) operator cannot be used with strings on SQL Server Compact.
There are several engine limitations which can affect complex LINQ queries, specifically around joining, grouping, composition (e.g. Intersect), subselects and the Distinct operator.
Migrations have only limited support on SQL Server Compact.