It all started in a morning when a colleague messaged me a question: “morning… I am trying to get parts of the email address being searchable under Elasticsearch. Do you have any idea?” My instant reply was “sure…? I thought this is for sure possible, isn’t it?” After some screenshots…

as a part-time content composer (aka author), striving to get a huge fan club is always a headache. You might wonder why a composer would need that amout of fans… the WHY following is a courtesty to recognize the composer’s work. Apparently why would somebody spend hours of preparation and editing to…

1. What is a SummingMergeTree? In Clickhouse, there are several Table Engine families and MergeTree(s) is the most popular one. If you are looking for OLTP features, the good old MergeTree should be good enough. However if you are looking additional features like the following: data deduplication AND summarization of numeric columns then SummingMergeTree is…

Clickhouse is a realtime OLTP (Online Transaction Processing) engine which uses SQL-like syntax. Talking about SQL, we can create Tables and Views to retrieve data. Usually View is a read-only structure aggregating results from 1 or more Tables — this is handy for report creation which required lots of input…

Clickhouse is a powerful realtime OLAP (Online Analytical Processing) system for your big data. Since it is “BIG” data, we would need to housekeep them in an efficient way. In this blog, we are going to explore a TTL (time-to-live) setting in Clickhouse where the data would be automatically housekept…

Clickhouse is a distributed DBMS for online analytical processing (OLAP) operations. It is by nature columnar-based and hence works great with Big Data analytics. Somehow Clickhouse works on Linux, Mac and PowerPC64LE CPU architectures only, which means it is not available on Windows (unless you are dual booting a Ubuntu…

Foreword A common use case of Elasticsearch is to act as a data pipeline — ingesting data from various sources and apply analytics for the data. But there are still use cases when these ingested data would require to integrate with external systems for further analysis. Take an example, integrate data…

Ever thought of executing an OS command within golang? Rarely suppose, but there are such scenarios. In this gotcha, we would be running a simple file logger and verify whether the logger is operating correctly by checking the number of lines logged within a unit test. Hm… you might say…

It sounds super simple to remove a document from an Elasticsearch data stream, isn’t it? But this is what happened this morning when I am trying to do so… Me: Let’s run a delete like this~ DELETE log-basic-dev/_doc/7vIUq3wBugmWpr_4Z3ps Kibana: bomber~ (lalalalala) { “error” : { “root_cause” : [ { “type”…