Blog

Teiid Translator API

Posted by Kylin Soong on Nov 10, 2014 categorized as teiid

Teiid Translator API under package org.teiid.translator, it can be quick viewed from https://github.com/teiid/teiid/tree/master/api/src/main/java/org/teiid/translator, the purpose of this article is for giving a high level overview of Teiid Translator API.

Execution interface

Execution interface

An execution represents the state and lifecycle for a particular command execution. The methods provided on this interface define standard lifecycle methods. Execution has define 3 methods:

  • close() - When execution completes, the close() will be called, the execution be terminated normally.
  • cancel() - If execution must be aborted, due to user or administrator action, the cancel() will be called, the execution be canceled normally. This will happen via a different thread from the one performing the execution, so should be expected to happen in a multi-threaded scenario.
  • execute() - Execute the associated command. Results will be retrieved through a specific sub-interface call.

The ResultSetExecution defines an execution for QueryExpression and Call that returns a resultset, which is represented through the iterator method next().

  • next() - Retrieves the next row of the resultset.

The ProcedureExecution represents the case where a connector can execute a Call. The output may include 0 or more output parameters and optionally a result set. It define one method:

  • getOutputParameterValues() - Get the output parameter values. Results should place the return parameter first if it is present, then the IN/OUT and OUT parameters should follow in the order they appeared in the command.

The ReusableExecution extends Execution and additional methods that may optionally be implemented for an Execution, it has 2 methods:

  • reset(Command c, ExecutionContext executionContext, C connection) - Called to reinitialized the execution for use.
  • dispose() - Called when the execution is no longer used.

The UpdateExecution represents the case where a connector can execute an Insert, Update, Delete or BatchedUpdates command, it extends Execution and one additional method:

  • getUpdateCounts() - Returns the update counts for the execution.