mysqldump 8 enabled a new flag called columm-statistics by default. When you have MySQL client above 8 and try to run mysqldump on older MySQL versions, you will get the error below. mysqldump: Couldn’t execute ‘SELECT COLUMN_NAME, JSON_EXTRACT(HISTOGRAM ‘$”number-of-buckets-specified”‘) FROM information_schema.COLUMN_STATISTICS WHERE SCHEMA_NAME = ‘myschema’ AND TABLE_NAME = ‘craue_config_setting’;’: Unknown …

Once you have SQL Server Express installed on your local machine, you may want to load some example data so that you can play around with it. After all, what’s good with the database without data! MySQL comes with the Sakila database upon installation. SQL Server’s equivalent would be AdventureWorks …

Once you install SQL Server Express locally, you need to go through a few configuration steps to connect to the server with JDBC. Tools In this demo, I am using SQL Workbench to connect to the server. SQL Server Express is 2017 version. JDBC is 7.1.x from Maven Repo. Steps …

This post explains steps for enabling the server authentication mode (logging in with username and password) after installing SQL Server Express in your local machine. This is based on 2017 version, but it also works for older ones. SQL Server Express comes with the default Windows Authentication mode when you …

MongoDB does not have authentication out of box. When you install it, the first thing you have to do is to create an admin user in the admin database and enable authentication. After installation, you can get into MongoDB with the mongo command from the Mongo Shell. mongo Let’s create …

The conventional wisdom is that, if you do not know what you are doing, you’re better off using the default configuration. Databases usually perform well with the default parameter values and premature performance optimisation often results in worse performance. On the other hand, Postgres is a different story. Postgres default …

Managing user access in MySQL is similar to Postgres (see Postgres user creation here). You can either manage the access privileges through roles or give privileges directly to users. This post is a quick reference for granting privileges to users. Let’s have a look at a simple use case. We …

When we transform JSON to a structured format with a programming language in JSON data ingestion, we have to handle missing key. This is because JSON is schema-less and it doesn’t always have the same keys in all records as opposed to relational database tables. In Python, the missing key …

In the previous post, we discussed the new JSON ingestion strategy by using the power of Postgres native JSON support functionality (New JSON Data Ingestion Strategy By Using the Power of Postgres). Since Postgres 9.5, it’s got a cool function jsonb_pretty() which automatically formats the output in the pretty JSON …

Creating user credentials and grand privileges in Postgres can be tricky. You have to make sure each user has the right access level to the right tables and schemas. Each database works differently even they all are relational databases. Postgres has its own way of creating users and granting privileges. …