Schema limits and constraints

This section covers limits on the numbers of database, tables and columns that can be present in an Engine repository.

Repository

For conventional Engine systems, it is possible to locate the Engine repository on a different machine to the Engine server - generally this is only recommended when the repository is stored on a Storage Area Network (SAN) or other high performance storage device

Databases

There is no limit on the number of databases that can be contained within a system. In practice it is the available memory that determines the maximum number of databases that can be effectively used.

Tables

Maximum Number of Tables

There is no limit on the maximum number of tables in any one database. In practice it is the available memory that limits the number of tables that can be effectively used.

Maximum Size of Table

The maximum number of records that can be stored in any one table is 2 billion (2,000,000,000). However, the practical limit ( in terms of useful performance ) on the number of rows in a table is usually dictated by available memory.

 

The size of the table affects the amount of memory required for the following:

• The memory for each domain on a table is dictated by the number of rows in the table
• Memory requirements to produce aggregates.
• The memory required to index columns or build links.

Column/Field

The more columns in the system the longer it will take for Engine to start up.

The maximum number of columns that can be present on any table is 32,768.

The maximum number of columns that can be present in the whole system is limited by the maximum number of system objects.

Maximum System Objects

There is no limit on the maximum number of objects that can be present in the system. In practice it is the available memory that limits the number of Objects that can be effectively used.