PgConf.Russia 2020

To build a decent query plan, the optimizer has to understand statistical characteristics of underlying data. It is interesting to observe how the structure of the collected information became more complicated over time: what the optimizer relied on back in its early days and what is at his disposal now with the release of the 12th version. We will also talk about how and when statistics are collected, how to manage this process and whether it is necessary to think about it at all.

Many businesses which use Database management systems like Oracle, DB2 & MS SQL are unreliable these days. Moreover, the costs incurred in maintaining these systems and its product licenses keeps on increasing. As the competitors are migrating over to the new technologies and tools available in the market, it is necessary for these businesses to migrate to new environment which is efficient, consistent and reliable to stay in the market and the technologies used in the current environment have become obsolete or no longer serve the business purpose. PostgreSQL has emerged as a top open-source RDBMS software. Since there is no licensing cost associated with it most of the companies are planning to migrate the databases which are currently running on other RDBMS like Oracle, DB2, MS SQL server to PostgreSQL. This report summarizes the various methodologies, procedures and techniques involved in successfully migrating the data from Oracle to PostgreSQL & DB2 to PostgreSQL. Migration is not a simple effort there should be proper planning and testing involved in this right from database connectivity to performance analysis. In this paper we are going to cover most of the steps which we need to consider before the migration and after the migration like choosing the correct tools for implementing the migration, time taken to migrate ,data compatibility, code conversion, application connectivity to database, database configuration parameters, performance analysis, replication setups, database monitoring, patching and backup strategies.

Recently, I was working on a project where graphQL was used for sending requests to its .NET Core backend, but this was not a good idea. The point is, a graphQL query is a hierarchical structure with a dynamic set of fields. It’s difficult to perform such requests via a statically-typed programming language and a relational database as suggested by the tools available. So, I came up with the idea of using the plv8 extension and perform graphQL queries right on the database side. It took me about two hours to develop a working prototype that could perform the same queries as the software under development for more than one month! Then various improvements have been made and I want to introduce them all. If you are thinking of using graphQL instead of REST, my speech could be most useful and could help you to save a lot of time.

In my talk, I will tell how we built a geographically distributed system of personal data storage based on Open Source software and PostgreSQL. The concept of the inCountry business is to provide customers with a ready-to-use infrastructure for personal data storage. Our business customers are ensured that their customer’s personal data is securely stored within their country’s borders. We wrote an API and SDK and built a variety of services. Our system complies with generally accepted security standards (SOC Type 1, Type 2, PCI DSS, etc.). We built our infrastructure with Consul, Nomad, and Vault, used PostgreSQL, ElasticSearch as a storage system, Nginx, Jenkins, Artifactory, other tools to automate management and deployment. We have assembled our development and management teams - DevOps, Security, Monitoring, and DBA. We use both cloud providers and bare-metal servers located in different regions of the world. Development of the system architecture and ensuring the stability of the infrastructure, consistent and secure operation of all its components is the main task facing our teams.