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PostgreSQL and Financial Calculations - Part Five

The fifth and last in a series of blogs covering common mistakes in Database and Application designs for financial calculations.

Method of Rounding:

There are many methods of rounding

  1. Half Round Up
  2. Half Round Down
  3. Round Towards Zero
  4. Round Away from Zero
  5. Round Half To Even
  6. Round Half To Odd
  7. Random Round

The built-in method of rounding in PostgreSQL is Half Round Up. Unfortunately, it is not the best approach, …

PostgreSQL and Financial Calculations - Part Three

The third in a series of blogs covering common mistakes in Database and Application designs for financial calculations.

Order of Operations and Storing Aggregate Results:

When working with float data types, order of operations will affect the ending value.

Consider 3:

justin@Debian10:~$ python3
Python 3.7.3 (default, Jul 25 2020, 13:03:44) 
>>> (1234.567 * 3.333333) + (1.234567 * 3.333333)
>>> (1234.567 + 1.234567 ) * 3.333333 …

PostgreSQL and Financial Calculations - Part Two

The second in a series of blogs covering common mistakes in Database and Application designs for financial calculations.

Inconsistent precision scaling:

This is probably the most common mistake in database design that I observe. It is understood to use exact data types (such as numeric) and the precision must be fixed, but for whatever reason the decision is made that it’s OK for one table to use numeric(12,4),a second table …

Recent blog updates

When you have been around as long as Command Prompt, you are bound to forget blogs you wrote as well as the fact that those blogs are likely exceedingly outdated. I was recently doing a review of the Command Prompt Dead Sea Scrolls and have come across two that we have updated to be accurate for the modern times of PostgreSQL.

The blogs

When is it time to fire a client?

Over the last 25 years we have interviewed hundreds of people to be a part of our team. As with any good interview, you allow candidates to ask questions about the business, how you operate, what your philosophy looks like, and hopefully what your plan for the future is. My favorite is, “What is something you tell every employee?” Our answer is always the same, “We are never afraid to fire a client” and the response is almost universally “that’s refreshing.”

Top 5 Reasons to Move to a Peer Review Focused Business

At Command Prompt, we rely heavily on peer review for the success of our clients. We believe that the best quality work is provided when there is no silo and when team work, no matter how much or how little, is a part of the day-to-day. When a group of individuals is encouraged to work together in an effort to provide high quality work and learn from each other, you’re …

Professional Development: How Our Team Sees It

Command Prompt has been providing infrastructure support to enterprises for over 20 years. As we are the only Postgres company still operating since the 90s, how is it that we’ve stayed standing? The answer is simple; we as a company and as a community firmly believe in the power of professional development. We frequently encourage everyone in our team, from interns to owners, to continue to learn and grow, both …

How to Achieve Success When Working From Home, Updated

Now that it’s been over a year, we thought it would be good to revisit the How to Achieve Success When Working From Home blog from March 2020. The idea of the original post was to help those who were challenged by the new work-from-home environment by sharing the knowledge that we’ve gathered over 15 years of working from home ourselves. Much has changed since that post was published, and …

Mark Porter: CTO MongoDB on PostgreSQL and MongoDB

I had an opportunity to sit down with Mark Porter, the CTO of MongoDB to discuss PostgreSQL, Aurora PostgreSQL and MongoDB. Mark is one of the creators of Aurora PostgreSQL and now enjoys a leadership role at MongoDB. There are two episodes:

It is important to reach out to leaders in communities to understand how they succeed. Mark has over 30 years of experience in …

Professional Development: No Box Required

The purpose of professional development is to strive to be better, to perform more effectively, to reach a higher professional level, and to know more in a world full of knowledge. While there are many continuing education classes, training, research, and reading opportunities, often these don’t fit our specific needs. Understanding how one learns may also impact how they should go about professional development. Sometimes thinking outside of the box …