Information about LocalDB comes from here and SQL Server Books Online. LocalDB is the full SQL Server Express engine, but invoked directly from the client provider. It is a replacement of the "User Instance" feature in SQL Server Express.
Feature |
SQL Server Compact 3.5 SP2 |
SQL Server Compact 4.0 |
SQLite, incl sqlite ADO Provider |
SQL Server Express 2012 |
SQL Server LocalDB |
Deployment/installation Features |
|
|
|
|
|
Installation size |
2.5 MB Download size MB expanded on disk |
2.5 MB Download size MB expanded on disk |
Ten MB download, MB expanded on disk |
Download MB Size > MB expanded on disk |
MB Download size > MB on disk |
ClickOnce deployment |
Yes |
Yes |
Yes |
Yes |
Yes |
Privately installed, embedded, with the application |
Yes |
Yes |
Yes |
No |
No |
Non-admin installation option |
Yes |
Yes |
Yes |
No |
No |
Runs under ASP. |
No |
Yes |
Yes |
Yes |
Yes |
Runs on Windows mobile/windows Phone platform |
Yes |
No |
Yes |
No |
No |
Runs on WinRT (Phone/store Apps) |
No |
No |
Yes |
No |
No |
Runs on Non-microsoft platforms |
No |
No |
Yes |
No |
No |
Installed centrally with an MSI |
Yes |
Yes |
Yes |
Yes |
Yes |
Runs in-process with Application |
Yes |
Yes |
Yes |
No |
No (as process started by app) |
64-bit Support |
Yes |
Yes |
Yes |
Yes |
Yes |
Runs as a service |
No–in process with Application |
No-in process with Application |
No-in process with Application |
Yes |
No–as launched Process |
Data file Features |
|
|
|
|
|
File format |
Single File |
Single File |
Single File |
Multiple files |
Multiple files |
Data file storage on a network share |
No |
No |
No |
No |
No |
Support for different file extensions |
Yes |
Yes |
Yes |
No |
No |
Database Size Support |
4 GB |
4 GB |
TB |
Ten GB |
Ten GB |
XML Storage |
Yes–stored as ntext |
Yes-stored as ntext |
Yes, stored as text |
Yes, native |
Yes, native |
Binary (BLOB) storage |
Yes–stored as Image |
Yes-stored as Image |
Yes |
Yes |
Yes |
FILESTREAM Support |
No |
No |
No |
Yes |
No |
Code free, document safe, file format |
Yes |
Yes |
Yes |
No |
No |
Programmability |
|
|
|
|
|
Transact-sql-common Query Features |
Yes |
Yes |
No |
Yes |
Yes |
Procedural t-sql-select case, If, features |
No |
No |
Limited |
Yes |
Yes |
Remote Data Access (RDA) |
Yes |
No (not supported) |
No |
No |
No |
ADO Sync Framework |
Yes |
No |
No |
Yes |
Yes |
LINQ to SQL |
Yes |
No (not supported) |
No |
Yes |
Yes |
ADO. NET Entity Framework 4.1 |
Yes (no Code first) |
Yes |
Yes |
Yes |
Yes |
ADO. NET Entity Framework 6 |
Yes (fully) |
Yes (fully) |
Yes (Limited) |
Yes |
Yes |
Subscriber for Merge replication |
Yes |
No |
No |
Yes |
No |
Simple transactions |
Yes |
Yes |
Yes |
Yes |
Yes |
Distributed transactions |
No |
No |
No |
Yes |
Yes |
Native XML, Xquery/xpath |
No |
No |
No |
Yes |
Yes |
Stored procedures, views, triggers |
No |
No |
views and triggers |
Yes |
Yes |
role-based Security |
No |
No |
No |
Yes |
Yes |
Number of concurrent connections |
256 (100) |
256 |
Unlimited |
Unlimited |
Unlimited (but only local) |
There is also a table here This allows you to determine which Transact-SQL commands, features, and data types are Supporte d by SQL Server Compact 3.5 (which is the same a 4.0 with very few exceptions), compared with SQL Server 2005 and 2008.
Comparison of SQL Server Compact, SQLite, SQL Server Express and LocalDB