PGConf.Online 2021

Postgres Pro DBMS: what’s new & what’s on the roadmap

In this talk, you'll learn about Postgres Pro DBMS from the co-founder of Postgres Professional. Ivan will explain the philosophy behind this enhanced variant of PostgreSQL, reveal the differences between Postgres and Postgres Pro and provide the roadmap for the further evolution of Postgres Pro DBMS.

Shardman - the native approach to sharding in PostgreSQL

The amount of data that is handled today by Enterprises and Web companies is constantly growing. At the same time, it becomes increasingly difficult to have and synchronize several copies of data in different systems. As a result there is a demand to work with large amounts of data directly in a transactional DBMS. This requirement is often imposed by the logic of applications that need real-time results. In this talk we will consider what a universal distributed transactional DBMS can be. We will analyze such aspects as the types of load and their prioritization, dynamic resource allocation and the level of consistency. What tools in PostgreSQL can be used to build such system, what we have already done and what is still missing.

Managing moving objects data with MobilityDB

MobilityDB is a moving object database extension to PostgreSQL and PostGIS. It has types and functions for storing an querying geospatial trajectories, as first class citizens. The main type is called tgeompoint (temporal geometry point). It represents a complete movement track of a geometry point, such as a car, a bird, or a person. The function speed(tgeompoint) computes the time varying speed of the object, as a tfloat (temporal float). Similar to these examples, MobilityDB has 6 temporal types, and over 300 functions. As such, it is a function-rich platform for Mobility Data Management.

In this tutorial you will:

• learn about moving object databases
• write MobilityDB SQL queries and explore a database of geospatial trajectories
• walk through the different type, indexes, and functions of MobilityDB.

Updating Materialized Views Automatically and Incrementally

Materialized view is a feature to store the results of view definition queries in DB in order to achieve faster query response. However, the data in the view gets stale after underlying tables are modified. Therefore, view maintenance is needed to keep the contents up to date. PostgreSQL has REFRESH MATERIALIZED VIEW command for updating a materialized view, but this command needs to recompute the contents from scratch, so this is not efficient in cases where only a small part of a base table is modified.

Incremental View Maintenance (IVM) is a technique to maintain materialized views efficiently, which computes and applies only the incremental changes to the materialized views instead of recomputing. This feature is required for updating materialized views rapidly but not implemented on PostgreSQL yet.

Therefore, we developed IVM on PostgreSQL and are proposing to implement this as a core feature. The patch is now under discussion on the hackers mailing list. Our implementation allows materialized views to be updated automatically and incrementally when a underlying table is modified. You don't need to write your own trigger function for updating views. As a result of continuous development, the current implementation supports some aggregates, subqueries, self-join, outer joins, and CTEs (WITH clauses) in a view definition query. The result of performance evaluation using TPC-H queries shows that our IVM implementation can update a materialized view more than 200 times faster than re-computation by REFRESH command.

In this talk, we will describe our IVM implementation and its features.