Parquet Dotnet Versions Save

• new feature: replaced default ToString() method in Table and Row object to produce json (#346)
• new feature: parquet CLI supports conversion from parquet to json (#341)

bug fixed: negative decimals were not properly written when using legacy mode (Impala) #275

• improvement: list and struct types implement IEquitable, GetHashCode and Equals for easier schema comparison
• bug fixed: nullable boolean field would not write due to a boolean conversion issues
• a lot of small improvements leading to Parquet.Net.Json first release

hotfix for #274

This is a new major release of Parquet.Net and a complete redesign reflected in documentation.

new features:

• map type is supported (#255)
• nested structures, repeated structures, repeated fields, nesting structures into structures etc. is supported (#226, #228, #227)

improvements:

• Parquet.Net is now a standalone library with no third-party dependencies whatsoever (#264, #265, #263)

new features:

• data representation internally changed to columnar format, resulting in much smaller memory footprint and better performance (#238)
• added support for short/ushort CLR type (#235)
• breaking change: nullable columns are easier to define, parquet.net doesn't try to guess the nullability anymore and gives full control to the user

improvements:

• BigDecimal type supports much bigger numbers (scale and precision) (#239)
• Writer was failing on some forward-only streams like GZipStream as they don't track stream position, now parquet.net supports all kinds of non-seekable streams for write operations (#252)
• Decimal number format is now compatible with Impala (#243)

bug fixes

• Writer was failing on columns consisting of only null values (#222)
• When appending to file and using DateTime for one of your columns, subsequent appends would fail on schema validation (#247)
• Failure when deserialising Impala generated file with all nulls in a column (#240)

new features:

• .NET byte and sbyte type is supported
• DataSet has got a new .Merge method that allows to merge two datasets, even if rows and columns are incompatible

improvements:

• we have removed a dependency on Snappy.Sharp completely which conflicted with projects targeting .NET 4.5
• dependency on System.ValueTuple is removed
• Apache Thrift dependency was replaced by a custom build which has zero downstream dependencies now. This was causing problems for projects using ASP.NET Core and specific Kestrel version, as stupidly enough Apache Thrift was referencing web hosting framework!

new features:

• INT64 (C# long) type is supported (#194)
• Decimal datatype is fully supported (#209). This includes support for simple System.Decimal, and decimal types with different scales and precisions. Decimals are encoded by utilising all three encodings from parquet specs, however this can be switched off for compatibility with older system. Decimals are fully compatible with Hive and Impala which have some edge cases not complying with parquet specifications. Thanks to @dmitryPavliv and @nzapolski for making this possible

bugs fixed:

• fixed a flaw in dictionary encoding implementation affecting files written for AWS Impala (#193)
• when a column contains only single value and it's null Parquet.Net was crashing (#198)