Gopal V created HIVE-7859: ----------------------------- Summary: Tune zlib compression in ORC to account for the encoding strategy Key: HIVE-7859 URL: https://issues.apache.org/jira/browse/HIVE-7859 Project: Hive Issue Type: Bug Components: File Formats Reporter: Gopal V
Currently ORC Zlib is slow because several compression strategies ZLib uses is already done by ORC in itself (dictionary, RLE, bit-packing). We need to pick between Z_FILTERED, Z_HUFFMAN_ONLY, Z_RLE, Z_FIXED and Z_DEFAULT_STRATEGY according to column stream type. For instance an RLE_V2 stream could a use Z_FILTERED compression without invoking the rest of the strategies. The string streams can use Z_FIXED compression strategies and so on. The core limitation to stick to retain compatibility with the default decompressor, so that these are automatically backward compatible. -- This message was sent by Atlassian JIRA (v6.2#6252)