Introduction

There are a set boundary conditions which dictate the layout for databases and the servers though which read/write access is granted. These are, Online & Offline require functional autonomy Write access is controlled at the "subsystem" (Online) or "domain" (Offline) level. MySQL provides simple (write) access control on a per database basis. While allowing copies (mirrors), data integrity requires 1 (& only 1) primary sink/source per DB Most database types have a well defined write clients in terms of Online & Offline : See list on DB-Types A simple schematic is shown here.

Online-Offline divisions

Below is a simple table to show the where the primary DB data source for the following database types. The term Primary Source refers to where write access is granted.

Navigation Structure

Below is a table of how one navigates (finds instances) within databases. This table corresponds to the "flow chart" and index specifications noted on the Navigation page.