allocated at start up and had no limit and which changed from a first in, first out (FIFO) buffer replacement policy to a least recently used (LRU) buffer replacement policy). Jet 3.0 also allowed for database replication. Jet 3.0 was replaced by Jet 3.5, which uses the same database structure, but different locking strategies, making it incompatible with Jet 3.0. Jet 4.0 gained numerous additional features and enhancements. Unicode character storage support, along with an NT sorting method that was also implemented in the Windows 95 version; Changes to data types to be more like SQL Server's (LongText or Memo; Binary; LongBinary; Date/Time; Real; Float4; IEEESingle; Double; Byte or Tinyint; Integer or Integer synonyms Smallint, Integer2, and Short; LongInteger or LongInteger synonyms Int, Integer, and Counter; Currency or Money; Boolean and GUID); a new decimal data type Memo fields could now be indexed Compressible data types SQL enhancements to make Jet conform more closely to ANSI SQL-92 Finer grained security; views support; procedure support Invocation and termination (committing or rolling back) of transactions Enhanced table creation and modification Referential integrity support Connection control (connected users remain connected, but once disconnected they cannot reconnect, and new connections cannot be made. This is useful for database administrators to gain control of the database) A user list, which allows administrators to determine who is connected to the database Record-level locking (previous versions only supported page-locking) Bi-directional replication with MS SQL Server. Microsoft Access versions from Access 2000 to Access 2010 included an "Upsizing Wizard" which could "upsize" (upgrade) a Jet database to "an equivalent database on SQL Server with the same table structure, data, and many other attributes of the original database". Reports, queries, macros and security were not handled by this tool, meaning that some manual modifications might have been needed if the application was heavily reliant on these Jet features. A standalone version of the Jet 4 database engine was a component of Microsoft Data Access Components (MDAC), and was included in every version of Windows from Windows 2000 on. The Jet database engine was only 32-bit and did not run natively under 64-bit versions of Windows. This meant that native 64-bit applications (such as the 64-bit versions of SQL Server) could not access data stored in MDB files through ODBC, OLE DB, or any other means, except through intermediate 32-bit software (running in WoW64) that acted as a proxy for