Database Design Phases & Models
This initial phase of database design involves interviewing domain experts to produce an implementation-neutral blueprint of user requirements.
What is the Conceptual Design Phase?
This sub-component enforces integrity constraints and ensures only authorized users have access rights to the database.
What is the Authorization & Integrity Manager?
This component is responsible for parsing Data Definition Language statements and recording those schema definitions directly into the data dictionary.
What is the DDL Interpreter?
This transaction property mandates an "all-or-nothing" execution, meaning a transaction either completes in full or has no effect at all.
What is Atomicity?
In this architectural mode, multiple CPUs exploit parallel processing while sharing a single, common pool of memory on a single server.
What is a Centralized (or Shared-Memory) Architecture?
This graphical method is one of two principal approaches used to capture enterprise entities and their relationships.
What is the Entity-Relationship (ER) Model?
This component fetches data pages from disk into main memory and manages the cache, allowing the DBMS to handle datasets far larger than the system's actual RAM.
What is the Buffer Manager?
This component translates Data Manipulation Language queries into low-level evaluation plans and selects the lowest-cost option from equivalent alternatives.
What is the DML Compiler?
This property guarantees that once a transaction successfully commits, its effects will permanently persist in the system, even through sudden hardware or system failures.
What is Durability?
This architecture pattern scales to large volumes and high throughput by running across a cluster of machines, distributing both storage and query processing across nodes.
What are Parallel Databases?
This algorithmic approach takes all attributes as an input to derive well-structured tables and eliminate data redundancy.
What is Normalization?
To allow rapid lookup of records by value without scanning entire data files, the storage manager maintains these structures, which are analogous to a book's index.
What are Indices?
This is the core task performed by the DML compiler to choose the absolute most efficient, lowest-cost execution plan for a query.
What is Query Optimisation?
This property ensures the database is moved cleanly from one valid state to another, allowing temporary inconsistencies only within the transaction boundary itself.
What is Consistency?
This type of deployment spans geographically separated machines, requiring extra mechanisms to maintain atomicity and concurrency control across different physical sites.
What are Distributed Databases?
This specific phase is responsible for mapping an approved conceptual schema to the specific data model supported by the chosen DBMS, such as the relational model.
What is the Logical Design Phase?
This physical data structure contains the metadata that describes the overall schema and structure of the database.
What is the Data Dictionary?
This specific engine is tasked with executing the low-level instructions produced by the DML compiler.
What is the Query Evaluation Engine?
This specialized manager prevents data corruption by coordinating multiple transactions that are executing simultaneously.
What is the Concurrency-Control Manager?
In this older, simpler architectural pattern, the application runs directly on the client machine and communicates straight to the database server, leading to lower scalability and security.
What is a Two-Tier Architecture?
This design phase specifies storage-level details like file organization and internal storage formats to optimize actual disk performance.
What is the Physical Design Phase?
This sub-component controls disk space allocation and manages the physical, on-disk data structures.
What is the File Manager?
The query processor as a whole frees users from having to worry about this level of the database system.
What is the physical level?
This specialized manager is responsible for restoring the database to its exact pre-failure state if a system crash occurs.
What is the Recovery Manager?
Considered the modern standard, this pattern introduces an application server between a thin client and the database to centralize business logic.
What is a Three-Tier Architecture?