Collection Contents Index Creating publications Partitioning tables that do not contain the subscription column pdf/chap8.pdf

Data Replication with SQL Remote
   PART 2. Replication Design for SQL Remote
     CHAPTER 8. SQL Remote Design for Adaptive Server Enterprise       

Publication design for Adaptive Server Enterprise


Once you understand how to create simple publications, you must think about proper design of publications. This section describes the issues involved in designing publications, and how to take steps towards sound design.

Top of page  Design issues overview

Each subscription must be a complete relational database 

A remote database shares with the consolidated database the information in their subscriptions. The subscription is both a subset of the relational database held at the consolidated site, and also a complete relational database at the remote site. The information in the subscription is therefore subject to the same rules as any other relational database:

Transaction integrity must be maintained in the absence of locking 

The data in the dispersed database (which consists of the consolidated database and all remote databases) must maintain its integrity in the face of updates at all sites, even though there is no system-wide locking mechanism for any particular row.

These key features of relational databases must be incorporated into the design of your publications and subscriptions. This section describes principles and techniques for sound design.

Top of page  Conditions for valid articles

All columns in the primary key must be included in the article.

Supporting INSERTS at remote databases 

For INSERT statements at a remote database to replicate correctly to the consolidated database, you can exclude from an article only columns that can be left out of a valid INSERT statement. These are:

If you exclude any column that does not satisfy one of these requirements, INSERT statements carried out at a remote database will fail when replicated to the consolidated database.

Conditions on rows 

There are two ways of including only some of the rows in a publication:

For Info     For more information on restrictions on rows, see Creating articles containing some of the rows in a table.

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Collection Contents Index Creating publications Partitioning tables that do not contain the subscription column pdf/chap8.pdf