OpenEdge Data Management: DataServer for Microsoft SQL Server

Creating a schema holder
Creating a schema holder
A schema holder contains a schema image of the MS SQL Server database that your
DataServer application accesses. The schema image contains the schema for your
data source—that is, its data definitions—in an OpenEdge format. Although OpenEdge
applications can access a data source directly by sending SQL statements through the
DataServer, they cannot directly access its data definitions and must use the
schema-image information instead.
Before you begin
Consider your business needs and deployment strategy when you decide where to
build your schema holder. The schema holder can reside on the client machine or on
any host in an enterprise configuration. Client schema holders improve performance
for some applications. Host schema holders give you the flexibility of having them run
as Windows services. Additionally, host schema holders might be easier to maintain.
In a WebSpeed configuration, placing the schema holder on the Transaction Server
machine optimizes performance.
General schema holder creation tasks
In general, you must do the following to create a schema holder:
1. Establish the appropriate server permissions needed for pulling the schema
image into the schema holder.
2. Perform some preparatory steps.
3. Create and then connect an empty OpenEdge database. This database becomes
your schema holder and contains your schema image.
4. Create the schema holder, which involves specifying connection parameters and
pulling the schema from the data source.
The following sections describe these steps in detail.
Permission requirements
When you use the DataServer to create a schema image in a schema holder, it
accesses the associated MS SQL Server database. This section describes the data
source permissions required when you create, update, or connect to a schema image.
Permissions for creating or updating a schema holder
You must have privileges to use the SELECT statement on certain data source objects
to perform certain tasks. In this chapter, these privileges are referred to as SELECT
privileges.
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