Architecture and Data Blog

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

Long Running Data Migrations during Database Refactorings.

When you are refactoring large databases, you will have certain tables that have millions of rows, so lets say we are doing the Move Column refactoring, moving the TaxAmount column from Charge table which has millions of rows to TaxCharge table. Create the TaxAmount column in the TaxCharge table. Then have to move the data from the TaxAmount column in the Charge table to the TaxAmount column you created in the TaxCharge table.

Implementing Make Column Non Nullable

While working on a Legacy Application with Legacy Database design as part of fixing a bug, I thought this bug would not have ever happened if a particular column was defined as Non Nullable since this particular column was the identifier to the parent table. We had a Customer table and the all the names a customer could have like LegalName, LongName, ShortName etc are stored in the CustomerName table. CustomerName cannot exist without Customer hence its logical that the CustomerName.

The day I received my Book

This last week I received my copies of the book, for the first time I could touch what I had worked on for almost a year and half now, I could see it flip the pages. When I opened the UPS box and saw the book for the first time it felt great but in a minute or two I was not feeling anything, after some tea and some walking around I took the book in my hands and started flipping the pages this is when the real feeling started to sink in, but still I was not sure of the situation, was not really sure if it was real, after about 2-3 hours when I saw the book and held the book and started reading, I was started feeling the joy the happiness and all the goodness.