Missing columns in PrestoSQL
One of the first issues when starting to use PrestoSQL distributed query engine is related to missing columns of certain data types, especially numeric and all variants of date. This issue is usually because of missing precision at the data source, which is not only one of the most common, but also one of the […]
Hybernate FetchType Eager performance issue
Quite recently I had one interesting case related to the quality of code generated by the Hybernate, in which I developed code which runs 25 thousand times faster than the code generated by the framework. It’s well known when you decide to use any framework to speed up code development process, you silently agree […]
Tuning Connection pool in modern Microservice architecture
Connection pool has always been a great way to ensure a low latency when establishing connection with a database, while at the same time keeping the number of open sessions under control. It’s one of the best ways to balance speed with resource consumption. With connection pool in place, connection is already established and ready […]
Trino (ex. Presto) – troubleshooting distributed transactions among various data sources
In this post I’ll demonstrate one of many use cases of Presto technology, that you might overlooked – How to troubleshoot distributed transactions which are very common these days as a result of a complex Microservices architecture. In the following SELECT statement I’ll combine three different data sources: Oracle Postgres Kafka by using good old […]
Trino (ex. Presto) – high performance distributed query engine
In this article I’ll share some of my experiences with Trino (ex. Presto) – high performance distributed query engine. First some intro about the project Presto. Couple of members from the Facebook infrastructure team created the project Presto to address problems they have with 300 Petabytes Hadoop Data Warehouse. The main goal of the […]
Postgres monitoring with Percona PMM
For those who are coming from Oracle world, the best alternative database is probably Postgres, because of many similarities between those two Db engines (data types, tablespace concept etc.). However, one of the first thing you want to do is to grab a full control over what is going on in your database. If […]
Dockly -Swiss army knife for managing Docker containers without Kubernetes
These days more and more vendors embrace Docker containers as preferable way of software distribution. In many cases you don’t need to deal with all the complexities that comes with Kubernetes orchestration. Instead you just want to have a simple tool which provides a full control and visibility over what is going on in containers […]
Kafka & TCP Retrans Error rate
Recently I had an interesting case where in the data pipeline I’ve found duplicate messages in the Kafka topics. Duplicate records in Kafka topics might appear for many different reasons, but most of them you can find only those related to the Kafka settings (especially those related to the Kafka settings). In this article you […]
PRIMARY KEY creation effect on SUPPLEMENTAL LOGGING
Recently I’ve discovered a bug that affects all versions of Oracle RDBMS from 11g up to the 19c. If you are using SUPPLEMENTAL LOGGING feature for any reason (security audit of logs, Data Guard, tables replication…) you might be affected. To follow my example you need to fulfill prerequisites to prepare database for supplemental logging. […]
Bashtop – future of the terminal Linux monitoring
Although the idea of the original top utility is follewed in many similar utilities for terminal based Linux monitoring, till now I’ve been using Htop, atop (which can monitor GPU on top of CPU/Mem/Net/Disk) and Nmon to do a job (later one, called „Topas on steroids” is ported from AIX to Linux). Quite recently I’ve […]