Architecture and Data Blog

Thoughts about intersection of data, devops, design and software architecture

Publish data models in CI Pipeline

Enable wider usage of data models by publishing the latest models on team Wikis

Many a times ER models are created by the data team and are not shared outside of the data team generally for the lack of tools licenses, since its not feasible for the entire team to purchase licenses for the ER modelling tools such as Erwin Data Modeller or Er Studio


SSL Connection to AWS Aurora

On a recent project we had to connect to AWS Aurora postgres 10.6 version of the database in SSL mode using JDBC and Java 11 JRE. When the Aurora cluster is setup, we can force all connections to use SSL by using the options group settings (forceSSL=true), establishing secure connection from the application to the database is not as easy as it looks.


Static Analysis of PL/SQL code

In all new development and sometimes during legacy codebase modernization, developers tend to add code quality checks and static analysis of codebase such as style checks, bug finders, cyclomatic complexity checking etc. into the CI/CD pipeline. When we inherit a codebase that has much PL/SQL and there is a desire to put the PL/SQL code base through the same types of code analysis, what options does a developer/dba have?

There are some options we can explore such as


Using liquibase to load data and ignore some columns

Loading data into tables is needed many times on projects to load test, Liquibase provides a method to load data into tables with lots of customization. In the example shown below, I’m loading zip code data with the following column layout

"Zipcode","ZipCodeType","City","State","LocationType","Lat","Long","Location","Decommisioned","TaxReturnsFiled","EstimatedPopulation","TotalWages"

Automatically adding columns to Rails migrations

Many projects need addition of identical columns to all the tables created by the project. Audit columns are an example of such a requirement. The requirement is to add columns such as created_by, created_date, modified_by and modified_date to all the tables, these columns store, who created the row, when the row was created, who modified the row last and when was it modified. created_by and created_date are required to be present when the row is inserted and thus are required to be not nullable. Adding these columns to each and every table is a lot of work for developers.


Synonyms as abstraction layer

In many development shops, developers are not allowed to access the database schema directly, and are not allowed to create tables, indexes, views etc, instead are given access via a different schema that allows SELECT, UPDATE and DELETE access on data. The general reason is to avoid developers creating database objects without


Using rake and activerecord to generate boilerplate DB Code

IN many projects, there are tables which need default audit columns such as Created_By, Created_Date, Modified_By, Modified_date and other columns that need to be updated every time some actions are done against the tables and/or columns. This type of functionality can be implemented using triggers.


Database naming conventions in different environments

In every enterprise and every project we end up having multiple environments, especially the database side of the enterprise tends to stick around for a longer period of time and has much more dependencies or application integration as opposed to application urls etc. Given this, how to name the servers, databases and schemas becomes a very important decision, do these names provide for an easy way to use the application and not make it harder or the developers to access the database.


Migrations in NoSQL databases

In relational database usage the pattern of migrations is well understood and has gained widespread acceptance. Frameworks such as DBDeploy, DBMaintain, MyBatis migrations, Flyway, Liquibase, Active Record Migrations and many others. These tools allow to migrate the database and maintain the version history of the database in the database. With the rise of NoSQL Databases and their adoption in development teams we are faced with the problem of migrations in NoSQL databases.

10 node mongodb ReplicaSet on a Single Machine

While doing evalauation of NoSQL databases, we had a 10 node riak cluster and wanted check how a similar setup would work with mongodb. So started to setup a 10 node mongodb cluster. Since this was for initial spikes, we decided to set this up on a single machine as with the other test setup using Riak. Before I explain how we setup 10 node mongodb ReplicaSet, let me talk about replica sets.