We are excited to announce NBCROW compression as a new feature in Kusto's TDS implementation. NBCROW stands for Null Bitmap Compressed Row. It is a data type that the Tabular Data Stream (TDS) protocol supports. TDS is a binary protocol that Kusto uses to communicate with MSSQL clients and return query results. NBCROW compresses the null values in a row of data into a bitmap, where each bit represents the presence or absence of a null value. This reduces the size of null values from 1 byte to 1 bit, saving 7 bits for each null value saving network bandwidth and improving query duration.
We hope you enjoy this feature and share your feedback with us.