Direct-connect functionality in a distributed database grid

A database is stored as a plurality of database shards in a distributed database grid comprising a plurality of grid elements, each including a mid-tier database system. A first grid element receives,from an application executing in the same memory as a mid-tier database system of the first grid element, a first database transaction including at least one database operation on specific data stored in a first database shard that belongs to the first grid element. The first grid element performs and commits the first database transaction without participation of another grid element. The firstgrid element receives a second database transaction that requires access to another database shard that does not belong to the first grid element. Multiple grid elements of the plurality of grid elements perform the second database transaction and commit the second database transaction using a two-phase commit protocol. 数据库被存储为在包括多个网格元素的分布式数据库网格中的多个数据库分片，每个网格元素包括中间层数据库系统。第网格元素从在与第网格元素的中间层数据库系统相同的存储器中执行的应用接收第数据库事务，第数据库事务包括对