ObjectExtender User's Guide and Reference
- ACID
- A mnemonic for the properties a transaction should have to satisfy the
Object Management Group Transaction Service specifications. A
transaction should be Atomic, its result should be Consistent, Isolated
(independent of other transactions) and Durable (its effect should be
permanent).
- atomic
- An atomic database transaction is one which is guaranteed to complete
successfully or not at all. If an error prevents a partially-performed
transaction from proceeding to completion, it must be "backed-out" to prevent
the database from being left in an inconsistent state.
- BO
- Business object. This term denotes the objects in your problem
domain that you wish to persist in a data store.
- cardinality
- Cardinality expresses the constraints on the number of instances that are
related through a relationship.
- code-generation
- The function whereby code is generated automatically given certain
specifications.
- CB
- Component Broker.
- connect/disconnect
- The attachment (or unattachment) of a target business object to/from a
link.
- consistency
- In the context of ACID: a transaction is a correct transformation of
the state. The actions taken as a group do not violate any of the
integrity constraints associated with the state. This requires that the
transaction be a correct program.
- counter
- Referring to the other side of a two-way business object
relationship.
- CRUD
- Create/Read/Update/Delete, the four basic types of operations on database
rows, records. ObjectExtender provides these operations on objects as
well.
- data model
- The term, data model is used here, to make a distinction between it and an
object model that you wish to persist. For example, the schema for a
relational database represents the data model. Your object model is
represented differently and will not need to be tightly coupled with the data
model representation.
- DDL
- Data Definition Language. A language enabling the structure and
instances of a database to be defined in a human- and machine-readable
form.
- DO
- DO is an acronym for data object. Data objects contain the data for
the business objects. The data is in the form in which it was retrieved
from the data store.
- durability
- In the context of ACID: Once a transaction completes successfully
(commits), its changes to the state survive failures.
- framework
- In object-oriented systems, a set of classes that embodies an abstract
design for solutions to a number of related problems.
- home collection
- Home collections provide the logical home for business objects.
They provide APIs for creating or locating instances.
- hydration
- The activity of populating the properties and relationships of a model
object.
- isolation
- In the context of ACID: even though transactions execute
concurrently, it appears to each transaction, T, that others executed either
before T or after T, but not both.
- link
- The infrastructure that connects source and target business objects in a
relationship.
- metadata
- Any information which describes according to prescribed specification a
target data.
- multiplicity
- See cardinality.
- nested transaction
- A nested transaction is a tree of transactions, the sub-trees of which are
either nested or flat transactions. Transactions at the leaf level are
flat transactions. The transaction at the root of the tree is called
the top-level transaction; the others are called subtransactions.
A transaction's predecessor in the tree is called a parent; a
subtransaction at the next lower level is also called a child . A
subtransaction can either commit or roll back; its commit will not take
effect though, unless the parent transaction commits. Therefore, any
subtransaction can finally commit only if the top-level transaction
commits. The rollback of a transaction anywhere in the tree causes all
its subtransactions to roll back.
- object model
- Object model is to data model what a hierarchy of classes is to a schema
of database tables. It is simply a distinction between the two
representations of how the data is represented.
- OO
- Object-oriented. Can apply to analysis, design, and programming
disciplines.
- persistence
- A property of a programming language where created objects and variables
continue to exist and retain their values between runs of the program.
This is in contrast to transient objects that cease existing when the
application that created them is not running.
- pre-fetch
- The notion of defining a path to set of data that you want to preload from
data store to object model to reduce the number of database trips improving
performance.
- relationship
- As understood in the context of the ObjectExtender framework, a
relationship is an instance variable in a business object which contains a
reference to another persistent object.
- transaction
- A unit of interaction with a DBMS or similar system. It must be
treated in a coherent and reliable way independent of other
transactions.
- UML
- Universal Modeling Language.
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