Hi Uwe,
Thank you for the quick reply! That was very helpful. I have another question regarding your low-level api example here https://github.com/apache/parquet-cpp/blob/master/examples/low-level-api/reader-writer.cc. in the "int32_field", the logical type is TIME_MILLIS and we put dummy data 0-499 (in int32_t) into this field. When I read the output parquet file by using the executable "parquet_reader" (in /parquet-cpp/build/latest folder), the value is still shown in int32_t primitive-data format (0 - 499) instead of in TIME_MILLIS logical-data format. Should it be this way? does the executable only read parquet file in primitive data type? Is there any ways to read the data in logical format? because I want to check if my final output is correct. Thanks! -Ivy On 2018/08/03 13:46:15, "Uwe L. Korn" <uw...@xhochy.com> wrote: > Hello Ivy, > > "primitive binary" means `Type::BYTE_ARRAY`, so you're correct. I have not > yet seen anyone use the JSON field with parquet-cpp but the JSON type is > simply a binary string with an annotation so I would expect everything to > just work. > > Uwe > > On Thu, Aug 2, 2018, at 7:59 PM, ivywu...@gmail.com wrote: > > Hi, > > I’m creating a parquet file using the parquet C++ library. I’ve been > > looking for answers online but still can’t figure out the following > > questions. > > > > 1. What does num_level mean in the WriteBatch method? > > WriteBatch(int64_t num_levels, const int16_t* def_levels, > > const int16_t* rep_levels, > > const typename ParquetType::c_type* values) > > > > 2. How to create a filed for JSON datatype? By looking at this link > > https://github.com/apache/parquet-format/blob/master/LogicalTypes.md, it > > seems JSON is not considered as a nested datatype. To create a filed > > for JSON data, what primitive type should it be? According to the link, > > it says “binary primitive type”, does it mean "Type::BYTE_ARRAY”? > > PrimitiveNode::Make(“JSON_field", Repetition::REQUIRED, Type:: ?, > > LogicalType::JSON)) > > > > Any help is appreciated! > > Thanks, > > Ivy > > >
