}
}
TruncateTableDesc truncateTblDesc = new TruncateTableDesc(tableName, partSpec);
DDLWork ddlWork = new DDLWork(getInputs(), getOutputs(), truncateTblDesc);
Task<? extends Serializable> truncateTask = TaskFactory.get(ddlWork, conf);
// Is this a truncate column command
List<String> columnNames = null;
if (ast.getChildCount() == 2) {
try {
columnNames = getColumnNames((ASTNode)ast.getChild(1));
// Throw an error if the table is indexed
List<Index> indexes = db.getIndexes(table.getDbName(), tableName, (short)1);
if (indexes != null && indexes.size() > 0) {
throw new SemanticException(ErrorMsg.TRUNCATE_COLUMN_INDEXED_TABLE.getMsg());
}
List<String> bucketCols = null;
Class<? extends InputFormat> inputFormatClass = null;
boolean isArchived = false;
Path newTblPartLoc = null;
Path oldTblPartLoc = null;
List<FieldSchema> cols = null;
ListBucketingCtx lbCtx = null;
boolean isListBucketed = false;
List<String> listBucketColNames = null;
if (table.isPartitioned()) {
Partition part = db.getPartition(table, partSpec, false);
Path tabPath = table.getPath();
Path partPath = part.getPartitionPath();
// if the table is in a different dfs than the partition,
// replace the partition's dfs with the table's dfs.
newTblPartLoc = new Path(tabPath.toUri().getScheme(), tabPath.toUri()
.getAuthority(), partPath.toUri().getPath());
oldTblPartLoc = partPath;
cols = part.getCols();
bucketCols = part.getBucketCols();
inputFormatClass = part.getInputFormatClass();
isArchived = ArchiveUtils.isArchived(part);
lbCtx = constructListBucketingCtx(part.getSkewedColNames(), part.getSkewedColValues(),
part.getSkewedColValueLocationMaps(), part.isStoredAsSubDirectories(), conf);
isListBucketed = part.isStoredAsSubDirectories();
listBucketColNames = part.getSkewedColNames();
} else {
// input and output are the same
oldTblPartLoc = table.getPath();
newTblPartLoc = table.getPath();
cols = table.getCols();
bucketCols = table.getBucketCols();
inputFormatClass = table.getInputFormatClass();
lbCtx = constructListBucketingCtx(table.getSkewedColNames(), table.getSkewedColValues(),
table.getSkewedColValueLocationMaps(), table.isStoredAsSubDirectories(), conf);
isListBucketed = table.isStoredAsSubDirectories();
listBucketColNames = table.getSkewedColNames();
}
// throw a HiveException for non-rcfile.
if (!inputFormatClass.equals(RCFileInputFormat.class)) {
throw new SemanticException(ErrorMsg.TRUNCATE_COLUMN_NOT_RC.getMsg());
}
// throw a HiveException if the table/partition is archived
if (isArchived) {
throw new SemanticException(ErrorMsg.TRUNCATE_COLUMN_ARCHIVED.getMsg());
}
Set<Integer> columnIndexes = new HashSet<Integer>();
for (String columnName : columnNames) {
boolean found = false;
for (int columnIndex = 0; columnIndex < cols.size(); columnIndex++) {
if (columnName.equalsIgnoreCase(cols.get(columnIndex).getName())) {
columnIndexes.add(columnIndex);
found = true;
break;
}
}
// Throw an exception if the user is trying to truncate a column which doesn't exist
if (!found) {
throw new SemanticException(ErrorMsg.INVALID_COLUMN.getMsg(columnName));
}
// Throw an exception if the table/partition is bucketed on one of the columns
for (String bucketCol : bucketCols) {
if (bucketCol.equalsIgnoreCase(columnName)) {
throw new SemanticException(ErrorMsg.TRUNCATE_BUCKETED_COLUMN.getMsg(columnName));
}
}
if (isListBucketed) {
for (String listBucketCol : listBucketColNames) {
if (listBucketCol.equalsIgnoreCase(columnName)) {
throw new SemanticException(
ErrorMsg.TRUNCATE_LIST_BUCKETED_COLUMN.getMsg(columnName));
}
}
}
}
truncateTblDesc.setColumnIndexes(new ArrayList<Integer>(columnIndexes));
truncateTblDesc.setInputDir(oldTblPartLoc.toString());
addInputsOutputsAlterTable(tableName, partSpec);
truncateTblDesc.setLbCtx(lbCtx);
addInputsOutputsAlterTable(tableName, partSpec);
ddlWork.setNeedLock(true);
TableDesc tblDesc = Utilities.getTableDesc(table);
// Write the output to temporary directory and move it to the final location at the end
// so the operation is atomic.
String queryTmpdir = ctx.getExternalTmpFileURI(newTblPartLoc.toUri());
truncateTblDesc.setOutputDir(queryTmpdir);