rdblue commented on code in PR #950: URL: https://github.com/apache/parquet-mr/pull/950#discussion_r842094667
########## parquet-hadoop/src/main/java/org/apache/parquet/hadoop/ParquetFileReader.java: ########## @@ -878,11 +880,97 @@ public String getFile() { return blocks; } - public void setRequestedSchema(MessageType projection) { + private boolean uniqueId(GroupType schema, HashSet<Type.ID> ids) { + boolean unique = true; + List<Type> fields = schema.getFields(); + for (Type field : fields) { + if (field instanceof PrimitiveType) { + Type.ID id = field.getId(); + if (id != null) { + if (ids.contains(id)) { + return false; + } + ids.add(id); + } + } + + if (field instanceof GroupType) { + Type.ID id = field.getId(); + if (id != null) { + if (ids.contains(id)) { + return false; + } + ids.add(id); + } + if (unique) unique = uniqueId(field.asGroupType(), ids); + } + } + return unique; + } + + public MessageType setRequestedSchema(MessageType projection, boolean useColumnId) { paths.clear(); - for (ColumnDescriptor col : projection.getColumns()) { + MessageType schema = null; + if (useColumnId) { + HashSet<Type.ID> ids = new HashSet<>(); + boolean fileSchemaIdUnique = uniqueId(fileMetaData.getSchema(), ids); + if (!fileSchemaIdUnique) { + throw new RuntimeException("can't use column id resolution because there are duplicate column ids."); Review Comment: Nit: error messages should use sentence case and begin with a capital letter. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: dev-unsubscr...@parquet.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org