Massoud Mazar

Sharing The Knowledge


How replacing ElasticSearch with Azure DocumentDB (CosmosDB) turned out to be a bad idea

Disclaimer: this is my personal opinion and not the opinion of my colleagues or my employer.


We used to store Terra Bytes of data in ElasticSearch in form of JSON documents. As the size of data stored in cluster grew, we had to create new clusters with lots of nodes and it turned to a maintenance and cost nightmare. Microsoft Azure team suggested we move to DocumentDB to reduce the cost, and since it can scale infinitely, there won't be any maintenance needed.  More...

From T-SQL to NoSQL

I know I have been stuck with SQL server for too long and a lot behind in adopting newer database technologies, but late is better than never. While updating a web application which uses SQL Server, I realized the current relational structure of my database is not really the optimal solution. I have more than 120 million rows of data in one of the tables which represent Option Chains for Stocks, one row per Option. I store this data as snapshots in time and do not change them after they are stored. Anyone familiar with this type of data knows that these individual rows are not really interesting by themselves and they are normally looked at alongside others which belong to the same Stock, and with same expiration. In real world you are presented with the whole chain (see an example of such data here). More...