Data migration
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When we move data from one system to another we transfer it. However, when you aim to permanently move data (most commonly when you are building a new system), we can say you are migrating data. Please know this is almost always a deliberate process.
The list below is used with gratitude from the Dartford Grammar School [2]. The list represent types of problems we can encounter when we migrate data:
- Incompatible file formats
- Data structure differences
- Validation rules
- Incomplete data transfers
- International conventions on dates
- Currencies & character set
Do you understand this material?[edit]
A small business has a computer kiosk inside the store which allows customers to sign up for a email newsletter. If a customer signs up for a newsletter inside the store, they will get a 10% discount on their first purchase at the store. The owner hopes this 10% discount will be an incentive for customers to sign up for the email newsletter. The business will then regularly email the customers special offers and savings. The business owner expects to benefit from this system by having increased sales. The customers expect to benefit from this system by having access to special offers, to save money, and to see what is new and trendy at their store.
The business owner is planning on migrating their customer data from Microsoft Excel to a relational database in the kiosk system. Outline two problems which might arise as they migrate the data:
Problem 1:
Problem 2:
Do you have an advanced understanding of this material?[edit]
A school of 900 students has a secure web-based application which manages attendance data. The school administrators carefully track attendance for the students so it can identify when students have been absent for a customizable threshold. For example, the school might set a threshold of 5 absences within 30 days, which then automatically notifies the student, parent, and teacher there is a problem with attendance. The threshold might be 3 times within 10 days, or something like that. The system keeps track of attendance and tardies. The system has customizable attendance codes. For example, "absence for school trip", "excused absence", "medical absence" are all allowed absence codes.
School administrators expect to benefit by having data about attendance so they can support students and parents to be in school. School administrators also expect to benefit by giving parents and students information about attendance (so parents can support their children to be in school). Finally, school administrators expect to benefit by using attendance data to apply for government funding (as they can prove how many students were in class on a specific day).
Parents expect to benefit by knowing when their children are in school or miss school. This way parents can support their children to be in school. Being in school is a shared value between the school and the parent.
Students expect to benefit by understanding how many days of school of they have missed. The school expects students to have a strong "ownership of learning" and manage their attendance.
The school is migrating from an old system using a totally different database. Outline two problems the school might encounter when migrating the data from the old system to the new system:
- Problem 1:
- Problem 2:
Standards[edit]
- Discuss problems that may arise as a part of data migration.