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An ONATTACH program is a program that you can create and that Oracle OLAP checks for by name when an AW ATTACH command executes.
When you attach an analytic workspace that contains a program named ONATTACH, unless the AW ATTACH statement includes an NOONATTACH clause or an ONATTACH clause that specifies a program with a different name, Oracle OLAP executes the ONATTACH program.
Depending on the statements in the onattach
program, the user is granted or denied access to specific objects or sets of object values. For multiwriter attachment, you can use ACQUIRE commands to provide access to individual workspace objects. For read-only and read/write attachment, you can use PERMIT commands that grant or restrict access to individual workspace objects. All of the objects referred to in a given onattach
program must exist in the same analytic workspace.
Note: Oracle OLAP checks for this program and other programs when a user attaches an analytic workspace. See "Startup Programs" for more information. |
Return Value
BOOLEAN
TRUE
when Oracle OLAP has successfully set up and attached the analytic workspace; or FALSE
when it has not or when the onattach
program has thrown an exception.
Note: You are encouraged to use the normal return values rather than relying on exceptions to create a return value ofFALSE . |
Syntax
To define a program with the name ONATTACH
use the syntax shown in DEFINE PROGRAM. Code the actual program as a user-defined function with the following argument.
ONATTACH ({READ|WRITE|EXCLUSIVE|MULTI} password)
Parameters
See AW ATTACH for explanations of the attachment modes (that is, READ, WRITE, EXCLUSIVE, and MULTI) and password.
Usage Notes
ONATTACH Programs Created by the OLAP API
When an analytic workspace is created as an OLAP cube using the OLAP API, the OLAP API may also create a program named ONATTACH. You can not modify an ONATTACH program that is automatically created in this way. Additionally, overriding the execution of this ONATTACH is not recommended.
Consequently, when this type of ONATTACH program exists in an analytic workspace, create a different type of startup program to specify behavior that you want performed when that analytic workspace is attached.
Examples
For examples of how attachment programs behave, see Example: Startup Programs.