Abstract: A set of techniques are described for transactional cache versioning and data storage in a distributed data grid environment. A transaction coordinator maintains a commit version for each transaction. This version is updated over the course of the transaction. In addition, each cluster member maintains a local current version that is updated as messages are received from the client. When a client serving as a transaction coordinator sends a message, the transaction coordinator includes an associated transaction's current version value with the message. On receiving a message, the receiving member process sets its current version to be the maximum of its own value and the received value. The receiving member process includes its current version in the return message to the sender. On receiving the return messages, the client sets the transaction's commit version to be greater than the maximum of its own value and the received value.

Abstract: A query explain plan is described for use with a distributed data system in order to help developers and IT experts to detect bottlenecks and to determine which queries are to blame for a slow running system. In accordance with an embodiment, the distributed data grid utilizes a facility to provide a distributed explain plan. This distributed explain plan provides visibility into how a query was answered by each node in the cluster. For example, one node may have applied the filters of the query in one sequence, while another node may have used a different sequence. Additionally, the distributed query explain plan can provide execution tracing, rendering information about the execution time of each step, total execution time and the like.

Abstract: A query explain plan is described for use with a distributed data system in order to help developers and IT experts to detect bottlenecks and to determine which queries are to blame for a slow running system. In accordance with an embodiment, the distributed data grid utilizes a facility to provide a distributed explain plan. This distributed explain plan provides visibility into how a query was answered by each node in the cluster. For example, one node may have applied the filters of the query in one sequence, while another node may have used a different sequence. Additionally, the distributed query explain plan can provide execution tracing, rendering information about the execution time of each step, total execution time and the like.

Abstract: A set of techniques are described for transactional cache versioning and data storage in a distributed data grid environment. A transaction coordinator maintains a commit version for each transaction. This version is updated over the course of the transaction. In addition, each cluster member maintains a local current version that is updated as messages are received from the client. When a client serving as a transaction coordinator sends a message, the transaction coordinator includes an associated transaction's current version value with the message. On receiving a message, the receiving member process sets its current version to be the maximum of its own value and the received value. The receiving member process includes its current version in the return message to the sender. On receiving the return messages, the client sets the transaction's commit version to be greater than the maximum of its own value and the received value.