Can a schema change?

Contents

1 Can a schema change?
2 What is the goal of schema therapy?
3 How does shared database and shared schema architecture work?
4 Can a schema change be mapped to a previous version?

The schema is part of what helps turn data into useful information. When a schema is changed, it creates a ripple through all the applications that depend on that schema. With relational databases, a schema change can take weeks for developers to deal with while they adapt their code to the new model.

Is schema the same as database?

Yes, in MySQL, schema and database are synonyms. This even extends to the syntax: CREATE DATABASE foo; DROP SCHEMA foo; CREATE SCHEMA bar; DROP DATABASE bar; Both a schema and a database is basically a namespace for tables.

What is the goal of schema therapy?

Schema therapy aims to teach you how to ensure your emotional needs are met in a healthy way that doesn’t cause distress.

How are schema changes propagated in SQL Server?

Transactional Replication Schema changes are propagated to Subscribers running previous versions of SQL Server, but the DDL statement should only include syntax supported by the version at the Subscriber. If the Subscriber republishes data, the only supported schema changes are adding and dropping a column.

How does shared database and shared schema architecture work?

The figure above shows how this approach manages data in the DB Tables. All Tenants/Clients will share the same set of tables, and a Tenant ID associates each tenant with the rows that it owns. This shared schema approach has the lowest hardware and backup costs, because it allows you to serve a large number of tenants/clients using one database.

When to make schema changes on publication databases?

Schema changes should be made only at the Publisher, not at Subscribers (including republishing Subscribers). Merge replication prevents schema changes at the Subscriber. Transactional replication does not prevent the changes, but the changes can cause replication to fail.