Unified Anchor Modelling

2023-11-13

With i-refactory you have the possibility to serve a mixture of OLTP and OLAP scenarios in a fully automated manner. In order to support these scenario's modelling concepts you need to balance availability versus quality. The Unified Anchor Modelling is an enhanced set of modelling patterns, evolved from Anchor Modelling and Data Vault. The modelling is closely aligned with the concepts of Fact Based Modelling.

We created the Unified Anchor modelling to specify the modelling construct of the Central Fact Layer. In order to be able to maintain full history, we split the business keys in Anchors and their context as Context. Context are functionally dependent (“belong to”) their Anchor. This context can consist of attributes describing the Anchor and/or relationships. This split is often referred to as ‘6th Normal Form’.

We keep track of existence for every Anchor: for each Business Key stored in the Anchor we track if that key was delivered in the last delivery. We assume that a business key is denoted as the primary key in a Logical Model.

All Anchors are ‘append only’: only new rows are added, a record in an Anchor will never be removed . By default we maintain history for all Context. Context can be logically or physically deleted.

Anchor: Independent Entity

An Independent Entity is an entity that implements an Anchor for a Business Key that ‘stands alone’ e.g. that does not contain a reference to another Entity. An Independent Entity contains Business Key fields, that show up as alternate key (AK), and the primary key (PK) is it's surrogate key (ID).

{info} With the Logical Model as your main reference, an independent entity can be identified by the following rule:

  • Entity has a primary key
  • None of the primary keys are foreign keys

Examples in TPCH: Customer, Order and Clerk.

Meta data stored for an Independent Entity:

  1. Audit ID - Process that created the record
  2. Entity ID - Reference to the Data Definition Register to the entity
  3. Existence - Indicates whether or not the key value is found (exists) in the most recent load of the entity
  4. Latest Start Datetime - the datetime at which the related context was last modified
  5. Last Created Datetime = Last Existence Datetime - the datetime at which the anchor existed (existence = true) most recently.

Anchor: Dependent Entity

A Dependent Entity is an entity that implements an Anchor for a Business Key that ‘depends’ in its existence on another Entity.

A Dependent Entity contains Business Key fields of which at least one is a foreign key (FK). The Business Keys will show up as alternate key (AK), and the primary key (PK) is it's surrogate key (ID).

{info} With the Logical Model as your main reference, a dependent entity can be identified by the following rule:

  • Entity has a primary key
  • At least one of the primary keys are foreign keys
  • The entity has a dependent relation to another entity

Dependent Entity
Dependent Entity

Examples in TPCH: Orderline Item and Part Supplier.

Meta data stored for a Dependent Entity equals to the metadata of an Independent Entity.

Context: Standard Context Entity

Context provides Context to an Anchor Entity and contains:

  • Attributes describing the Context
  • Relationships to Anchors (even to the same Anchor Entity)
  • Every record is linked to the Anchor (reference named ID) as part of the Primary Key of the Context Entity
  • Every record in a Context Entity is ‘timestamped’ with a Start- and End Datetime
  • The Start Datetime is part of the Primary Key

Examples in TPCH: Part Supplier S Properties and Order Line Item S Properties.

{info} A Context Entity will be populated of the Attributes and relationships that are not part of the primary key.

The attributes in an entity in the Logical Model can be split over multiple Context Entities. Reasons to split one logical model entity into multiple Context Entities:

  1. Multi Active or bi-temporal behavior.
  2. Split of immutable attributes.
  3. Separate identification and uniqueness validation for Alternate Keys (see later).
  4. Rate of change (avoid data duplication of stable data).
  5. Runtime / information logistic considerations: each table can only be loaded from one table.
  6. Or any other physical / implementational consideration.

Metadata stored for a Context Entity:

  1. Start datetime of the transaction timeline - the transaction datetime uniquely identifies each change in the context. For batch processing this date is provided as part of the metadata of a delivery. For transactional processing the time is set when the data is committed.
  2. End datetime of the transaction timeline - this field will be end dated if the record is logically deleted or updated.
  3. Audit ID - Process that created the Entity.
  4. Entity ID - Reference to the Data Definition Register to the entity.
  5. Record Indicator - indicates whether a record is a New record (N), result of an update (A) or logical delete (R).

Context Entity
Context Entity

The example shown above shows that first record is a new Record (‘N’) to Anchor with ID = 1. The functional Value is ‘aap’. For the same Anchor (with ID = 1) there are two more updates performed. The functional value is changed to 'noot' followed by 'mies'. Both updates are marked as appended update (‘A’). Last record is still open because the End datetime is dated in the future. Records are logically closed by physically updating the end date with the datetime of the next record.

We only INSERT records, we deviate from this rule to:

  • set end dates for transaction timeline in context entities
  • set existence and update metadata of anchors entities
  • support physical deletion of context and registration of physical deletion on the Anchor.

Context: Immutable Context Entity

Immutable Context is a Context Entity for which all attributes and relationships are ‘insert once’: once the context is provided, it will never change. By doing so no history will be maintained.

As soon as context is provided for an Anchor, its context won’t be updated even if (changed) content is delivered. No errors or warnings are shown. Only when an update is provided via a CRUD-transaction processing call, an error will be returned.

{warning} Be aware: Updates by sources are ignored when processing Immutable Context.

In a Logical Model it is not visible whether context is immutable or not. This information should be specified by a modeller in the Central Facts Layer.

An example of Immutable Context could be meter readings or strict bookkeeping systems that allow no updates on financial transactions and thus enforce a reverse transaction instead.

Context: Bi-temporal Context Entity

A Bi-Temporal context is a context extended with two additional columns to store a valid timeline: Valid Start Datetime and Valid End Datetime. The Valid Start Datetime is part of the primary key, hence the primary key of a Bi-Temporal context is a composite key consisting of three columns: id, ACM Start Datetime, Valid Start Datetime.

A Bi-Temporal context cannot be used to track the existence of a key, for this you need to add a standard context (possibly a "dummy" context without any context columns).

Context: Multi-Active Context Entity

Multi-Active Context is a Context Entity that contains a Multi Active (Versioning Key) extending the business key of the associated Anchor.

{info} Each Multi Active Business Key has its own context which is functional dependent from the business key in the Anchor extended by the Multi Active Business Key.

This implies that one business key can have multiple context records at the same time.

Example: a customer has multiple types of phone numbers. “Home”, “Work” and “Mobile”. We add a Multi Active Key “Phone Nbr Type”.

LDM Phone Numbers
LDM Phone Numbers

Let's assume your logical model specified the relation between customer and customer phone numbers as shown above. How can this be reflected in the CFL ?

  1. First alternative is to use Multi-Active Context
  2. Second alternative is to define a Dependent Entity for Customer Phone with it's own context

Alternatives
Alternatives

What alternative should you use?

  • Benefit of an Anchor is that it can have its own contexts and can be referred to from other places in the model. However, an Anchor adds extra storage and extra joins.
  • For an Anchor existence is stored as metadata. For a multi active key there is no existence stored.

{info} Rule of thumb: if we know for sure that there is and will never be context to the multi active key we can create a Multi Active Entity especially when performance and/or volume are important considerations. Choosing for an Anchor is more flexible but less efficient.

Context: Alternate Key Context Entity

Alternate Key Context is a Context Entity with an additional uniqueness constraint over it's alternate key columns.

{info} An Alternate Key Context only holds Alternate Keys that are treated as unique. If you combine Alternate Keys in one Context, the combination is treated as unique.

Relation: Foreign Key Link

A Foreign Key Link relates Anchor Context to another Anchor. It's a formalization of a foreign key relation as defined in your Logical DataModel.

The main benefits of Foreign Key Links are:

  • simplification of the UAM Model construct,
  • reduces number of joins by eliminating the use of a separate Dependent Entity as relation construct
  • the loading pattern is determined automatically: you can load Context of Anchor A if the key as specified in the Foreign Key Link exists in Anchor B.

Relation: Super-Subtype Construct

A Subtype forms a subset of the business keys of its Supertype. A subtype is an (in)dependent entity on which existence is maintained. As an additional step, any insert to the subtype creates a record in the supertype.

Subtype
Subtype

Subtypes are designated in your Logical Datamodel by the Subtype-symbol. The subtype construct can be Mutually exclusive and/or Complete. Check on these constraints should be part of the Logical Validation Model checks. No constraints are implemented in the CFL.

It is not necessary that every subtype is also physically implemented as a CFL subtype. Attributes of subtypes can be stored at their supertype. Formally a subtype describes a relation only.

Anchor: Generalization

A Generalization pattern defines a Supertype of more than one Anchor. This pattern generalize Anchors with different Business Keys. Generalization Patterns are relevant for use cases when :

  • You define relations to the Generalization Concept
  • You maintain Context on the level of Generalization Concept as "common attributes"

Anchor: Key Root

This pattern is mainly used in a separate Concept Integration Model. A Key Root integrates entities of different Models that share the same Business Key. The KeyRoot is a technical construct that manages the integration within the Central Facts Layer. Since a Key Root only manages the integration based on keys, a Key Root cannot have any context.

Constraint violation actions are applicable to certain constraint categories. Not all combinations of constraint categories and violation actions are allowed.

An attribute must have a value, whatever that value may be. It must not be NULL.

A data type of an attribute defines what value an attribute can hold. The data type specifies what type of mathematical, relational, or logical operations can be applied to it without causing an error.

An attribute datatype constraint is the most basic constraint type. It checks for the datatypes we support and have implemented.

For example, we check for string, length of string, integer, date, etc. In the following figure you can see the supported data types by PowerDesigner.

Image is omitted: Supported data types

Constraints can be violated and there are some actions that can be performed when a violation occurs. The possible actions are: EMPTY COLUMN, NO ACTION and SKIP ROW.

An attribute value constraint is an expression that is evaluated. The person who writes the expression is responsible for the correctness of it. The expression should be formulated in a positive way and lead to a Boolean answer. If the expression validates to True, than the value is correct.

Examples

  • The values in attribute X has to be bigger than 10: X > 10
  • The email address has to be in a certain pattern: email address LIKE '%_@_%.__%'

A Concept Integration Model is also a central facts model on which you place integration patterns. It is not required to create a concept integration model, but it can be very useful.

Every constraint is assigned to a constraint classification.

The main purposes of the Generic Data Access Layer (GDAL) are to provide logical perspectives for data consumption and to manage CRUD actions.

A generic data access model is a virtual data model that acts as an interface bridge between consumer applications and the central fact storage.

Every attribute is assigned to an attribute classification.

An entity record constraint checks whether an attribute meets the requirements set by another attribute belonging to the same entity.

The main purpose of the Logical Validation Layer (LVL) is to transform the data received from external data sources to fit into the logical data model structure. It is also responsible for validating deliveries. The Logical Validation Layer is also known as the Historical Staging In (HSTGIN) Layer.

The logical validation model is the representation of a single external data source in a logical format. It represent how data delivered by a specific tenant should be transformed, temporalized and validated in the {popup}logical validation layer. The logical validation model is also known as Historical Staging model (HSTGIN).

Multi-active attributes are attributes that contain a business key to provide multiple context records at the same time. For example: a customer has multiple types of phone numbers. “Home”, “Work” and “Mobile”. In that case we add a dependent entity on customer with key “Phone Nbr Type”. This is to prepare for the CFPL multi-active key on customer.

The main purpose of the Technical Staging Layer (TSL) is to create a common starting point for further data processing. It receives data delivered from external data sources and temporally stores them in a database. The input data should be in a tabular format (rows and columns).

Bi-temporal attribute is an attribute that changes over time: they follow a valid timeline. For example, a Part may have a price valid for December and a price valid for January.

Every entity is assigned to an entity classification and to a parent entity classification. The possible values for entity classification are: ALTERNATE KEY CONTEXT, ATTRIBUTE CONTEXT, GENERALIZATION,HELPER, REFERENCE CONTEXT, STABLE, STABLE DEPENDENT and STABLE INDEPENDENT

Entity Set Constraint An entity set constraint can be used to perform a check concerning values of two or more attributes that belong to different entities or to perform a check concerning the value of an attribute with respect to a set of values.

A Set Constraint Helper is a helper in the logical validation model. It is the implementation of a set constraint. The helper returns the records of an entity for a given set constraint, where the instances of this entity do not meet the definition of this set constraint.

The business requirements describe how data should be delivered for the data consumers (end users or applications) in terms of concepts, relationships between concepts and constraints to validate the data. These requirements can be described in a logical data model, for example.

A Business Rule Helper is a helper in the central facts model. It is a set-based calculation of derived facts. You need to use a Business Rule Helper if you want to make a calculation and want to keep a transaction history of the results of this calculation. You use the existing entities from the central facts model as input. The results of the helper must be materialized in 'regular' fact entities, such as Anchors and Contexts, to make them accessible in the Generic Data Access Layer.

Closed Open means that the timeline is valid from (vanaf in Dutch) the supplied valid start date until - but not including - (tot in Dutch) the supplied valid end date. In practice, this means that the start date of a valid time record is equal to the end date of the previous valid time record.

You need to create context-based entities when a set of data may be delivered within the boundaries of a parent context. A context-based entity applies when:

  • At least 2 entities are delivered.
  • A context relationship exists between these 2 entities. One entity is the parent context of the other entity.
  • The parent context entity is delivered as a delta and the child entity is delivered as a full set.

You need to create context-based entities when a set of data may be delivered within the boundaries of a parent context. A context-based entity applies when:

  • At least 2 entities are delivered.
  • A context relationship exists between these 2 entities. One entity is the parent context of the other entity.
  • The parent context entity is delivered as a delta and the child entity is delivered as a full set.

The Management Model contains the PowerDesigner objects for the Unified Anchor Modelling (UAM). When a UAM object is created, a so-called PowerDesigner replica of the corresponding Management Model object is created. This means that certain properties such as metadata columns and column stereotypes are configured in the Management Model and cannot be changed. The replication settings specify which elements of an object can be changed after creating a replica from the template object. It is possible to override the replication settings of an UAM object and change a specific property.

The temporal atomic type describes the datatype of the temporal attributes|

The main purposes of the Central Facts Layer (CFL) is to store data historically. It can also integrate data from different sources. The Central Facts Layer is also known as Central Facts Persistency Layer (CFPL)

The central facts persistence implementation model is the representation of facts in an anchorized data model with the ability to integrate multiple logical models.

In the context of i-refactory, data transformation refers to operations involved in turning raw data readily useful and closer to the business requirements.

Integration patterns are used to integrate entities from different data models. If two or more entities from different data models share the same business key, you can use the Integration Pattern named Key Root. It is a good practice to capture integration patterns in a separate model, named Concept Integration Model.

An attribute is mandatory when its value can not be empty (NULL).

A Physical Data Model (PDM) represents how data will be implemented in a specific database.

{note} The i-refactory uses four PDMs: technical staging model, logical validation model, central facts model and generic access model. Each one of these models is implemented as an additional database, which is used to store data from external and internal data sources.

Reverse engineering is the process of reconstructing a physical and/or Entity Relationship (ER) model from an existing data source. The purpose of reverse engineering is to avoid manual work as much as possible.

Architecture layer

The core of the i-refactory architecture has four layers: TSTGIN, LVL, CFL and GDAL. There are also two auxiliary layers: UCLVL and EXT.

If an entity has one or more attributes that changes over time and you want to keep track of when a attribute is valid at a certain transaction time, then you have a special case of a regular dependent entity, called bi-temporal entity. The bi-temporal entity stores historical data with two timelines. The primary key of the bi-temporal entity is composed by the primary key of the parent entity and the valid start date attribute. The attribute that changes over the valid time is called a bi-temporal attribute.

If an entity has one or more attributes that changes over time and you want to keep track of when a attribute is valid at a certain transaction time, then you have a special case of a regular dependent entity, called bi-temporal entity. The bi-temporal entity stores historical data with two timelines. The primary key of the bi-temporal entity is composed by the primary key of the parent entity and the valid start date attribute. The attribute that changes over the valid time is called a bi-temporal attribute.

A delivery agreement is a contract between a Tenant and a Logical Implementation Model or Generic Data Access model. An agreement has a duration. The delivery agreement set the architecture layer (interface) where the data should be ingested as well as the default settings to be applied to the deliveries.

A dependency mapping is a mapping between a helper (or BR helper) and a source entity used in the query of the helper. The helper and the source entity must belong to the same model.

  • Default dependency is set on entity level (source entity to helper entity)
  • To allow lineage on attribute level, via the Mapping editor, you could manually add the dependency on attribute level.

An Independent Entity is an entity that implements an Anchor for a Business Key that ‘stands alone’ e.g. that does not contain a reference to another Entity.

An Independent Entity is an entity that implements an Anchor for a Business Key that ‘stands alone’ e.g. that does not contain a reference to another Entity.

A Logical Data Model (LDM) matches the language, structure and quality of the business, regardless of the physical data implementation. The Logical Data Model reflects the business requirements.

A delivery may be considered as "untrusted" if deletes of data in the Logical Validation Layer have taken place and the processing of new deliveries cannot 100% rely (trust) on having enough statistics and data available to detect logical deletes, to determine the exact delta and to execute set based validations.

A delivery may be considered as "untrusted" if deletes of data in the Logical Validation Layer have taken place and the processing of new deliveries cannot 100% rely (trust) on having enough statistics and data available to detect logical deletes, to determine the exact delta and to execute set based validations.

A Dependent Entity is an entity that implements an Anchor for a Business Key that ‘depends’ in its existence on another Entity. A Dependent Entity contains Business Key fields of which at least one is a foreign key (FK).

A Dependent Entity is an entity that implements an Anchor for a Business Key that ‘depends’ in its existence on another Entity. A Dependent Entity contains Business Key fields of which at least one is a foreign key (FK).

The transaction time in i-refactory is different from what is commonly understood by transaction time. Transaction time is usually seen as the moment when a fact was stored in the database. In the i-refactory, the transaction time is the time, as dictated by the source system, not by the i-refactory database.

The Attribute type links the attribute to one of the existing interfaces.

Computed columns are columns whose content is computed from values in other columns in the table.

Functional date A functional date or time is a point in time and is defined by a user. An example is an order date or date of birth.

The technical model (also known as Technical Staging In model: TSTGIN) is a representation of how exactly one delivery from a specific data source will be processed in the technical staging layer.

Generalization is the process of extracting shared characteristics from two or more classes (hyponyms), and combining them into a generalized superclass (hypernym). For example: an 'employee' and a 'customer' are both 'persons'.

The Mapping Editor provides a graphical interface for creating and viewing mappings between models. It provides a global view of all the mappings related to the entities of a given model, allowing you to quickly identify those which are mapped and not mapped.

When a certain fact can change over time and you need to capture when that fact is valid in the real world, you can add a valid start date and a valid end date to the entity.

A valid time tells us in which period a record is valid. While a functional date represents just one point in time, the valid time has a begin and an end date, for example:

  • For Order item 123, a Retail price of 10.00 was valid from 2019-01-01 to 2019-06-01.
  • For Order item 123, a Retail price of 12.00 was valid from 2019-06-01 to 2020-01-01.

Alternate key is an attribute or a group of attributes whose values uniquely identify every record in an entity, but which is not the primary key

Candidate key

A candidate key consists of one or more attributes and meets the following requirements:

  • Unique: The value of the key defines uniquely one instance of a concepts. There are no double values.
  • Non-volatile: (Almost) doesn't change.
  • Minimal: Contains only the elements needed.

There are two kinds of candidate keys:

  • primary key
  • alternative key

Normalization is the process of decomposing tables in a database in order to reduce data redundancy and improve data integrity.

A strongly typed model is a model in which each all attributes have a predefined data type, for example: integers, doubles, date.

Surrogate Key A surrogate key is a system generated unique identifier that does not have any contextual or business meaning.

Business Key

A business key is an unique identifier that has business meaning and exists in the real world outside of the database. It consists of a column or a set of columns that already exists in a table. A business key is also known as a natural key

A Key Root Hub is an integration concept that must be used when the exact same business concept or independent business key occurs in different models. The Hubs for this independent business key in the different UAM models are all subtypes of the Keyroot Hub.

A relationship shows how two entities are related to one another. For example, a customer can place an order, and a order can have a customer.

Every Attribute has an atomic type (data type) which is linked to the attribute type of that attribute.

The cardinality shows how many instances of an entity can take place in a relationship.

The cardinality shows how many instances of an entity can take place in a relationship.

An enumeration consists of the list of values that a given attribute should adhere to.

{example} An order can have different statuses, such as shipped,packing,created anddone. Other statuses are not allowed.

Foreign Key

A foreign key is an attribute or a set of attributes that refers to the primary key of another entity. The original entity containing the primary key is called the 'parent' entity and the entity containing the foreign key is called the 'child' entity.

A natural key is an unique identifier that has business meaning and exists in the real world outside of the database. It consists of an column or a set of columns that already exists in a table. A natural key is also known as a business key

The primary key is an assigned key that consists of a minimal set of attributes to uniquely specify an instance of a record. The attribute or a combination of attributes should meet the following characteristics:

  • Unique: The attribute values of the key uniquely identify one instance of a concept. There are no duplicate instances.
  • Non-volatile: The key does not change.
  • Mandatory: All values are filled; there are no NULL values.

It is good practice to choose a primary key that also meet the following characteristic:

  • Safe: Doesn't contain private or sensitive information, such as a social security number.

Constraints are related to the other elements depending of the type of the constraint. Certain constraints are associated to attributes, entities, helper entities, unique keys or relationships between entities.

An attribute may be assigned to one or more entities (ex: acm_exists_ind) and an entity may have several attributes

Each layer may have one or more interfaces. The amount of interfaces depend on how many tenants and delivery agreements have been configured.

Namespace is what in the terminology of SQL Server is called database schema.|

A Delivery is a container that holds the specification of what is actually pushed to the i-refactory platform. This specification consists of a list of entities.

A Delivery is a container that holds the specification of what is actually pushed to the i-refactory platform. This specification consists of a list of entities.

Key Root A Key Root is a central repository for Business Keys. A Key Root ensures that similar records out of different data sources are identified by both the same Business Key as the Surrogated Key.

Context

A Context is a temporal table with a transaction start and end date. The Context tracks all changes of the context attributes related to a business key in the transaction time. This means that every change of an attribute value in a source system leads to a new record in the Context. The old record is end dated with the load date and the new record is start dated with the load date.

Hyponym is a term that denotes a subcategory of a more general class. For example: 'cat' and 'dog' are a hyponyms of 'animal'.

A mapping establishes relationships between concepts of separate data models. It creates a link between entities and attributes from a source model to related entities and attributes in the target model. A source model should precede the target model in the i-refactory architecture.

oasi_bk is an abbreviation for One Attribute Set Interface (OASI) with business keys. A normal view in the generic data access layer (GDAL) consists of the surrogate key, foreign key and attributes. The oasi_bk-view in the GDAL is a view where the business key(s) are also shown.

A subtype is a subgroup of an entity. You can create a subtype if a group of instances share some attributes and relationships that only exist for that group. For example, entity Customer can have a subtype Company and a subtype Person. They share the common attribute customer number, and can have some attributes of their own. Such as birth date for a Person. The entity Customer is called a supertype.

A subtype:

  • inherits all attributes of the supertype
  • inherits all relationships of the supertype
  • usually has one or more own attributes
  • can have subtypes of its own

Anchor: Independent Entity

An Independent Entity is an entity that implements an Anchor for a Business Key that ‘stands alone’ e.g. that does not contain a reference to another Entity.

Anchor: Dependent Entity

A Dependent Entity is an entity that implements an Anchor for a Business Key that ‘depends’ in its existence on another Entity.

A domain will help you to identify the types of information in your model. It defines the set of values for which a column is valid. A domain can specify a data type, length, precision, mandatoriness, check parameters, and business rules. It can be applied to multiple columns, which makes it easier to standardize data characteristics for columns in different tables.

Each interface may have one or more entities and one entity belongs to only one interface. An entity belongs to an i-refactory data model.

Each interface may have one or more entities and one entity belongs to only one interface. An entity belongs to an i-refactory data model.

A helper entity creates a derived entity and can be used when you need to transform, filter, or calculate data. The purpose of a helper differs per model:

  • Technical model: a helper is used to transform data.
  • Logical validation model: a helper is an implementation of a set constraint (Set Constraint Helper).
  • Central facts model: a helper is used for a set-based calculation of derived facts (Business Rule Helper).

HSTGIN is the abbreviation of Historical STaging IN. It is an older term to indicate the Logical Validation Model or Logical Validation Layer.

A schema is a set of database objects, such as tables, views, triggers, stored procedures, etc. In some databases a schema is called a namespace. A schema always belongs to one database. However, a database may have one or multiple schema's. A database administrator (DBA) can set different user permissions for each schema.

Each database represents tables internally as <schema_name>.<table_name>, for example tpc_h.customer. A schema helps to distinguish between tables belonging to different data sources. For example, two tables in two schema's can share the same name: tpc_h.customer and complaints.customer.

A Tenant is a delivering party for a dataset or datarecord as agreed in the Delivery Agreement.

TSTGIN is the abbreviation of Technical STaging IN. It is an older term to indicate the Technical Model or Technical Staging Layer.

An index organizes data in a way that improves the speed of data retrieval from a database. To maintain the index data structure, there is a cost of additional writes and storage space.

An index organizes data in a way that improves the speed of data retrieval from a database. To maintain the index data structure, there is a cost of additional writes and storage space.

The acronym CRUD stands for create, read, update, and delete. These are the four basic functions of persistent storage.

OLAP is a acronym for Online Analytical Processing. OLAP is category of software tools which provide analysis of data for business decisions. It uses complex queries to analyze aggregated historical data from OLTP systems.The primary objective is data analysis and not data processing.

OLTP is a acronym for Online transaction processing. OLTP captures, stores, and processes data from transactions in real time. Its primary objective is data processing and not data analysis.

A hub or independent entity is an entity that implements an Anchor for a business key that ‘stands alone’ e.g. that does not contain a reference to another entity. An independent entity contains business key fields, that show up as alternate key (AK), and the primary key (PK) is its surrogate key (ID).

A key is a combination of one or more attributes of an entity that uniquely defines one instance of that entity.