Debezium and pt-online-schema-change or gh-ost
When I first started working with Debezium, I needed to monitor tables in a Percona MySQL cluster and we used the pt-online-schema-change Percona’s tool to make online schema changes on tables, this means with no downtime.
Outbox pattern in JSON with Debezium
If you are not familiar with the outbox pattern, this article gives a very rich introduction with step by step instruction.
String aggregation with databases and ETL tools
String aggregation is the process of concatenating strings (usualy as a list with a separator) based on a common key. Databases implement their own function to do so such as wm_concat or LISTAGG in Oracle, group_concat in MySQL, array_agg or string_agg with PostGres. Some databases doesn’t support it at all, such as MS SQL Server (before the 2017 version) and require workaround. The implementation on the ETL tools side also depends on the vendor.
Variables declaration ordering error in Informatica and Talend
Understanding how in-flow variables are declared by your ETL tool is important. Probably all of them requires the user to declare the variables in the right orders. But what happens when there is an ordering error in a component of your flow.