JSON and JSONB maximum size on NPS

Message systems like Kafka are often used as an enterprise nervous system for data. A datawarehouse like Netezza Performance Server needs to be able to consume this data for analysis and reporting. Most organizations prefer the loading of their data warehouse to happen in two stages: One that ingests data in a staging area or data lake and one that loads this further into facts and dimensions. The first requires a data store where data can be inserted in its raw format with little transformation. The latter loads this data and transforms it into an efficient but flexible structure that can be reported on. Recent versions of NPS introduced JSON and JSONB datatypes. These make it possible to use NPS as such data lake/staging/event store because messages from Kafka can be ingested at high insert rates with little transformation, preserving the structure of the original message, while making them queryable by NPS embedded indexes e.g. with a connector like this one https://github.com/gertschouten/kafka-connect-jdbc-event-store. Preliminary testing results show that projecting, filtering and aggregating JSONB columns with help of the json functions gave excellent performance and looks very promising. However the implementation of JSON on Netezza uses nvarchar behind the covers. This restricts data stored as this datatype to maximum 16000 character, 64 kilobytes in size. It is this size restriction that are a blocker for real life implementations where an NPS database is used as event store. Realistic events payloads quickly exceed this size. PostgreSql and Oracles equivalent implementation which use respective Text and BLOB do not impose this restriction. This enhancement request is about increasing the size limit of JSON and JSONB on NPS so that NPS with its excellent MPP performance can be used in event store patterns with realistically sized messages.