Press "Enter" to skip to content

Month: February 2026

TO_CHAR() in Oracle vs Postgres

Published 2026-02-02 by Kevin Feasel

Deepak Mahto diagnoses a tricky difference in behavior:

You migrate a perfectly stable Oracle application to PostgreSQL.

  • The SQL runs
  • The tests pass
  • The syntax looks correct
  • Nothing crashes

And yet… the numbers or query calculations are wrong.

Not obviously wrong. Not broken. Just different.
Those are the worst bugs the ones that quietly ship to production. This is a story about one such bug, hiding behind familiar operators, clean-looking conversions, and false confidence.

Read on for the story.

Leave a Comment

Building an Ubuntu VM from Powershell Script

Published 2026-02-02 by Kevin Feasel

Vlad Drumea has a script:

I needed a fresh Ubuntu VM in VirtualBox this weekend so I figured I can take this opportunity to refresh my PowerShell based process.

Prerequisites

For this VM I’m using the following:

  • Oracle VirtualBox 7.2.6 r172322 running on a Windows host.
  • The installation media (ISO file) for Ubuntu 24.04.3 LTS.
  • 51GB of available space on the drive where the VM will live.
    Note that the default Ubuntu install is ~10GB, but I want the extra space to be able to install other stuff later on.

Click through for the script and explanation of the process. It’s not entirely automated, but Vlad does get to the Ubuntu installation point via Powershell and then takes it up from there.

Leave a Comment

Columnstore Storage Structures

Published 2026-02-02 by Kevin Feasel

Hugo Kornelis continues a series on storage structures:

In the first part of this series, I described the storage structure and access patterns for SQL Server’s traditional storage structure: on-disk rowstore indexes (heaps and B-trees).

Columnstore indexes were introduced in SQL Server 2012. In that version only nonclustered columnstore indexes were supported (so they stored a copy of the data in the included columns, with the actual table data still stored in an on-disk rowstore heap or clustered index. And they made the table read only! That restriction was lifted in SQL Server 2014, when clustered columnstore indexes were also added. SQL Server 2016 then added the option to create additional nonclustered (on-disk rowstore) indexes on a clustered columnstore. And, also since SQL Server 2016, we now have ordered columnstore indexes – in my opinion a somewhat misleading name.

Read on to see how SQL Server manages this data.

Leave a Comment

Local Admin and SQL Server

Published 2026-02-02 by Kevin Feasel

Rebecca Lewis follows Betteridge’s Law of Headlines:

“Does a DBA need local administrator membership to manage SQL Server?”

The answer is simple: Local admin group membership is not required. In fact, best practices dictate that Database Administrators (DBAs) and SQL service accounts should not have local administrator rights on the host server.  This change was introduced as far back as SQL Server 2008 with a ‘secure by design, secure by default, and secure in deployment’ strategy.

Read on for the caveat of what happens when you don’t provide local admin access to your DBAs.

Leave a Comment