1. A storage medium storing one or more sequences of instructions which, when executed by one or more processors, cause the one or more processors to perform steps comprising: receiving columnar data, wherein the columnar data is represented as a list of length-value pairs, and wherein each length-value pair includes a data value and a length of the data value expressed as a number of bytes; for each two consecutive length-value pairs in the list of length-value pairs, computing a delta pair that includes: a delta length that is computed as the byte-wise numerical difference between the lengths included in said each two consecutive length-value pairs; and a delta value that is computed as the byte-wise numerical difference between the data values included in said each two consecutive length-value pairs; transforming the columnar data into transformed data, wherein the transformed data includes a base length-value pair, from the list of length-value pairs, and a list of the computed delta pairs; compressing the transformed data into compressed data; and storing the compressed data into persistent data storage.