Snappy compression ration1/2/2024 White space in column name is not supported for Parquet files. Note currently Copy activity doesn't support LZO when read/write Parquet files. Supported types are " none", " gzip", " snappy" (default), and " lzo". Unless the random number generator is a very bad one, random data doesn't have any patterns and so doesn't compress well. When reading from Parquet files, Data Factories automatically determine the compression codec based on the file metadata. 2 Answers Sorted by: 3 Compression algorithms work by identifying repeating patterns in the data, and replacing those patterns with identifiers that are significantly smaller. The compression codec to use when writing to Parquet files. See details in connector article -> Dataset properties section. Each file-based connector has its own location type and supported properties under location. The type property of the dataset must be set to Parquet. This section provides a list of properties supported by the Parquet dataset. Dataset propertiesįor a full list of sections and properties available for defining datasets, see the Datasets article. By default, the service uses min 64 MB and max 1G. This means that JVM will be started with Xms amount of memory and will be able to use a maximum of Xmx amount of memory. The flag Xms specifies the initial memory allocation pool for a Java Virtual Machine (JVM), while Xmx specifies the maximum memory allocation pool. Because all of them needs C compiler, you have to manually install them. lz4, lower ratio, super fast Note some package are not installed along with compress. If you copy data to/from Parquet format using Self-hosted Integration Runtime and hit error saying "An error occurred when invoking java, message: :Java heap space", you can add an environment variable _JAVA_OPTIONS in the machine that hosts the Self-hosted IR to adjust the min/max heap size for JVM to empower such copy, then rerun the pipeline.Įxample: set variable _JAVA_OPTIONS with value -Xms256m -Xmx16g. snappy, from Google, lower compression ratio but super fast (on MacOS, you need to install it via brew install snappy, on Ubuntu, you need sudo apt-get install libsnappy-dev. Snappy is a compression algorithm reaching over 250MB/s compression and 500MB/s decompression speeds while still providing interesting compression ratio.
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