Business Objectives and Requirements

Asking questions in the areas of data distribution and data modification helps you determine how to distribute data, what type of replication to use, what replication options to use, what the business needs are for replication, and who will be affected by replication.

Data Distribution

Answering questions about the objective of distributing data ensures that replication is the correct solution for the problem you need to solve or goal you hope to attain. Answering questions about the needs of the organization regarding data distribution helps you plan where replication is needed and how often, and determine the type of replication to use. These questions include:

• What is the core problem or objective that replication might help solve? For example, do you want to distribute data for reporting servers, do you have applications that need to be updated online and offline, or do you want a standby solution?
  
  
• How will data distribution affect existing technology, administrative resources, people who currently access the data, and costs of data administration?
  
  
• What data is needed and where is it needed?
  
  
• How often is the data needed?
  
  
• Are entire refreshes of the data required or just incremental updates?
  
  
• Are entire tables needed, or can you filter the data according to site or data usage? Do you want to replicate database objects such as stored procedure definitions or execution, views, triggers, or user-defined functions?
  
  
• Where will data be published and what Subscribers need to receive the data?
  
  
• How many Subscribers need the data?
  
  
• Are data transformations necessary during replication?

Data Modification

Answering questions about modifying data helps you determine what types of replication to use, what replication options to use, and when to schedule updates.

• Do Subscribers need to update the data?
  
  
• If multiple Subscribers update the same sets of data, are conflicts allowed?
  
  
• Do transactions have dependencies? Will dependent transactions be affected if a transaction has dependencies and that transaction is undone due to a conflict?
  
  
• If data modifications are made at Subscribers, what is the rate of data modification?
  
  
• Will Subscribers have continuous, reliable connections to the publication database or will they be disconnected for periods of time?
  
  
• Can data be partitioned logically so that various sites can modify their own subsets of data without the possibility of updates causing conflicts with updates made at other sites?
  
  
• If multiple sites are updating the same data independently, how will conflicts be handled?
  
  
• How quickly must changes be replicated to other sites?
  
  
• How quickly must the initial snapshot and data be applied at the Subscriber?
  
  
• How often will Subscribers synchronize data or propagate changes?
  
  
• How many updates are you sending?