Введение

MongoDB\Driver\ReadConcern controls the level of isolation for read operations for replica sets and replica set shards. This option requires the WiredTiger storage engine and MongoDB 3.2 or later.

Обзор классов

Предопределенные константы

MongoDB\Driver\ReadConcern::LOCAL

Queries using this read concern will return the node's most recent copy of the data. This provides no guarantee that the data has been written to a majority of the nodes (i.e. it may be rolled back).

This is the default read concern level.

MongoDB\Driver\ReadConcern::MAJORITY

Queries using this read concern will return the node's most recent copy of the data confirmed as having been written to a majority of the nodes (i.e. the data cannot be rolled back).