The CSV scanner kernel can be described as:
maximal number of input files: as we have only 12 processing units (PU) inside the kernel, the maximal number of input files should be limited to 12 at one call.
Data types: 5 data types are supported currently, including: int (64-bit), string (up to 1024 chars), date, bool, and numeric (56-bit significand, 8-bit exponent).
CSV format: up to 16 columns are supported, up to 8 columns post CSV parsing, and the length of one row should be less than or equal to 1024 bytes.
filter operator: only 7 types of operator are supported, the operators are listed below:
FilterOp Description FOP_DC don’t care FOP_EQ equal FOP_NE not equal FOP_GT greater than FOP_LT less than FOP_GE greater than or equal FOP_LE less than or equal