Returns number of key-value pairs.

Returns the largest decoded row number + 1, i.e. rows.end().

Helper function that creates a simple expression plan and executes it against rowVector. Don't spend too much time trying to follow this code, If you

@returns: a pointer to the page's data

\brief Define the encoding that is used when we don't utilise dictionary encoding. This either apply if dictionary encoding is disabled or if we fall

A field_id -1 (or any negative value) will be serialized as null in Thrift

Has the semantics as std::string, except that it does not fill the space[size(), newSize] with 0 but rather leaves it as is

'size' is with respect to the current size of the array being written.

Returns the flat or constant base vector.

`size` is with respect to the current size of the map being written.

Return the pointer to values data. The number of values equals to size().

Indicates if this buffered writer has pending data to flush or not.