diff --git a/ndb/include/ndbapi/Ndb.hpp b/ndb/include/ndbapi/Ndb.hpp index dcde0a66872..9ff7f2cf5f5 100644 --- a/ndb/include/ndbapi/Ndb.hpp +++ b/ndb/include/ndbapi/Ndb.hpp @@ -21,7 +21,7 @@ on http://dev.mysql.com/doc/mysql/en/NDBCluster.html . Some of the fundamental ones are also described in section @ref secConcepts. - The NDB API is a MySQL Cluster application interface + The NDB API is a MySQL Cluster application interface that implements transactions. The NDB API consists of the following fundamental classes: - Ndb_cluster_connection, representing a connection to a cluster, @@ -36,7 +36,7 @@ - NdbDictionary represents meta information about tables and attributes. - NdbError contains the specification for an error. - It is also possible to receive "events" on changed data in the database. + It is also possible to receive "events" triggered when data in the database in changed. This is done through the NdbEventOperation class. There are also some auxiliary classes. @@ -44,31 +44,32 @@ The main structure of an application program is as follows: -# Construct and connect to a cluster using the Ndb_cluster_connection object. - -# Construct and initialize Ndb object(s) to connect to a database. - -# Define and execute transactions using NdbTransaction. + -# initiate a database connection by constructing and initialising one or more Ndb objects. + -# Define and execute transactions using the NdbTransaction class. -# Delete Ndb objects. - -# Delete cluster connection. + -# Terminate the connection to the cluster (terminate instance of Ndb_cluster_connection). - The main structure of a transaction is as follows: - -# Start transaction (an NdbTransaction) - -# Add and define operations associated with the transaction using - NdbOperation, NdbScanOperation, NdbIndexOperation, NdbIndexScanOperation + The procedure for using transactions is as follows: + -# Start transaction (instantiate an NdbTransaction object) + -# Add and define operations associated with the transaction using the + NdbOperation, NdbScanOperation, NdbIndexOperation, and NdbIndexScanOperation classes. -# Execute transaction The execution can be of two different types, Commit or NoCommit. If the execution is of type NoCommit, then the application program executes part of a transaction, - but without committing the transaction. + but without actually committing the transaction. After executing a NoCommit transaction, the program can continue to add and define more operations to the transaction for later execution. If the execute is of type Commit, then the transaction is - committed. The transaction must be closed after it has been + immediately committed. The transaction must be closed after it has been commited (event if commit fails), and no further addition or definition of - operations is allowed. + operations for this transaction is allowed. + @c STOP POINT -- js @section secSync Synchronous Transactions