public static List<FieldSchema> getFieldSchemaList(List<HCatFieldSchema> hcatFields) {
if (hcatFields == null) {
return null;
} else {
List<FieldSchema> result = new ArrayList<FieldSchema>();
for (HCatFieldSchema f : hcatFields) {
result.add(HCatSchemaUtils.getFieldSchema(f));
}
return result;
}
}
/**
* Validate partition schema, checks if the column types match between the partition and the
* existing table schema. Returns the list of columns present in the partition but not in the
* table.
*
* @param table the table
* @param partitionSchema the partition schema
* @return the list of newly added fields
* @throws IOException Signals that an I/O exception has occurred.
*/
public static List<FieldSchema> validatePartitionSchema(Table table, HCatSchema partitionSchema)
throws IOException {
Map<String, FieldSchema> partitionKeyMap = new HashMap<String, FieldSchema>();
for (FieldSchema field : table.getPartitionKeys()) {
partitionKeyMap.put(field.getName().toLowerCase(), field);
}
List<FieldSchema> tableCols = table.getCols();
List<FieldSchema> newFields = new ArrayList<FieldSchema>();
for (int i = 0; i < partitionSchema.getFields().size(); i++) {
FieldSchema field = HCatSchemaUtils.getFieldSchema(partitionSchema.getFields().get(i));
FieldSchema tableField;
if (i < tableCols.size()) {
tableField = tableCols.get(i);
if (!tableField.getName().equalsIgnoreCase(field.getName())) {
throw new HCatException(
ErrorType.ERROR_SCHEMA_COLUMN_MISMATCH,
"Expected column <"
+ tableField.getName()
+ "> at position "
+ (i + 1)
+ ", found column <"
+ field.getName()
+ ">");
}
} else {
tableField = partitionKeyMap.get(field.getName().toLowerCase());
if (tableField != null) {
throw new HCatException(
ErrorType.ERROR_SCHEMA_PARTITION_KEY, "Key <" + field.getName() + ">");
}
}
if (tableField == null) {
// field present in partition but not in table
newFields.add(field);
} else {
// field present in both. validate type has not changed
TypeInfo partitionType = TypeInfoUtils.getTypeInfoFromTypeString(field.getType());
TypeInfo tableType = TypeInfoUtils.getTypeInfoFromTypeString(tableField.getType());
if (!partitionType.equals(tableType)) {
throw new HCatException(
ErrorType.ERROR_SCHEMA_TYPE_MISMATCH,
"Column <"
+ field.getName()
+ ">, expected <"
+ tableType.getTypeName()
+ ">, got <"
+ partitionType.getTypeName()
+ ">");
}
}
}
return newFields;
}