/** Insert rows through staging phase */
private void insertRowsThroughStaging(
TaskAttemptContext taskAttemptContext,
InsertNode insertNode,
Path finalOutputPath,
Path stagingDir,
Path stagingResultDir)
throws IOException {
EvalExprExec evalExprExec =
new EvalExprExec(taskAttemptContext, (EvalExprNode) insertNode.getChild());
InsertRowsExec exec = new InsertRowsExec(taskAttemptContext, insertNode, evalExprExec);
try {
exec.init();
exec.next();
} finally {
exec.close();
}
FileSystem fs = TajoConf.getWarehouseDir(context.getConf()).getFileSystem(context.getConf());
if (insertNode.isOverwrite()) { // INSERT OVERWRITE INTO
// it moves the original table into the temporary location.
// Then it moves the new result table into the original table location.
// Upon failed, it recovers the original table if possible.
boolean movedToOldTable = false;
boolean committed = false;
Path oldTableDir = new Path(stagingDir, TajoConstants.INSERT_OVERWIRTE_OLD_TABLE_NAME);
try {
if (fs.exists(finalOutputPath)) {
fs.rename(finalOutputPath, oldTableDir);
movedToOldTable = fs.exists(oldTableDir);
} else { // if the parent does not exist, make its parent directory.
fs.mkdirs(finalOutputPath.getParent());
}
fs.rename(stagingResultDir, finalOutputPath);
committed = fs.exists(finalOutputPath);
} catch (IOException ioe) {
// recover the old table
if (movedToOldTable && !committed) {
fs.rename(oldTableDir, finalOutputPath);
}
}
} else {
FileStatus[] files = fs.listStatus(stagingResultDir);
for (FileStatus eachFile : files) {
Path targetFilePath = new Path(finalOutputPath, eachFile.getPath().getName());
if (fs.exists(targetFilePath)) {
targetFilePath =
new Path(
finalOutputPath, eachFile.getPath().getName() + "_" + System.currentTimeMillis());
}
fs.rename(eachFile.getPath(), targetFilePath);
}
}
}
