pub fn read_batch<R>(
reader: &mut R,
dictionaries: &AHashMap<i64, Box<dyn Array>>,
metadata: &FileMetadata,
projection: Option<&[usize]>,
limit: Option<usize>,
index: usize,
message_scratch: &mut Vec<u8>,
data_scratch: &mut Vec<u8>
) -> Result<Chunk<Box<dyn Array>>, Error>
Expand description
Reads the record batch at position index
from the reader.
This function is useful for random access to the file. For example, if you have indexed the file somewhere else, this allows pruning certain parts of the file.
§Panics
This function panics iff index >= metadata.blocks.len()