Table of Contents
31) How Can you communicate with an RDBMS?
You have to use SQL to communicate with the RDBMS using queries of
SQL to provide the input to the Database. After processing the queries, the Database will provide us with the required output.
32) When does a checkpoint occur in DBMS?
A checkpoint is a snapshot of the DBMS’s current state. The DBMS uses checkpoints to limit the amount of work required during a restart in the event of a subsequent crash.
Mainly, the log-based recovery solution employs checkpoints, so we won’t have to execute the transactions from the beginning.
33) What integrity rules are in the DBMS?
Two important integrity rules exist in the DBMS:
Entity Integrity: This states an essential rule that the value of a Primary key can’ be a NULL value.
Referential Integrity: This rule pertains to the foreign key, which may either have a NULL value or maybe the primary key for another relation.
34) What is Indexing?
Indexing is a data structure method that helps you quickly retrieve records from a database file. An index is a small table with only two columns. The first column comprises a table’s primary or candidate key.
The second column includes a set of pointers for holding the address of the disk block where a particular key value is stored.
35) What is Data Independence?
Data independence is a technique that helps you access data strategy.”
It allows you to modify the schema definition in one level and should not affect it in the next higher level.
36) What is ER Diagram?
Entity Relationship Diagram, also called ERD, displays the relationship of entity sets stored in a database. This diagram using in DBMS to help to explain the logical structure of databases. These DBMS diagrams are created based on three basic concepts: entities, attributes, and relationships.
37) What is Hashing in DBMS?
In a DBMS system, hashing is a method to directly find the location of requested data on the disk need to use an index structure. A shorter hashed critical value is used in place of the original critical value when indexing and retrieving items in the Database.
38) What is Transparent DBMS?
Transparencies in DBMS means a DBMS system should offers a transparent distribution to the user. In other words, it hides implementation detail from the user. There are 4 kinds of transparency: distribution transparency, transaction transparency, performance transparency, and the DBMS transparency itself.
39) What is Conceptual Design in DBMS?
Conceptual Design is the primary stage in the Database design process.
The main goal at this stage is to design a database independent of database software and physical details. A conceptual data model describes this process’s main data entities, attributes, relationships, and constraints.
40) What is Data Mining?
Data mining is a step-by-step process of sorting through a large amount of data that allows you to identify trends and patterns.
It uses complex statistical and mathematical Algorithms to segment data to predict likely outcomes. There are numerous tools for data mining, like RapidMiner, Teradata, Solver, Silences, etc.
41) What is Query Optimization?
Query optimizations is a process of identifying an execution plan with the least estimated cost and time for evaluating and executing every query in the DBMS system.
42) Define the term ‘Store Procedure’.
The concept of a stored procedure is quite similar to that of a function, as it contains a series of coordinated operations. It includes a set of processes frequently used in applications to perform database activities.
43) What is Timestamp-based Protocols?
Timestamp-based Protocol in DBMS is an algorithm that uses the System Time or Logical Counter as a timestamp. It helps to serialize the execution of concurrent transactions. This protocol ensures that every conflicting read and write operation is executed in timestamp order.
Or
Timestamp-based protocols in dbms are used to order the transaction in ascending order of their creation time. The creation time is the system time or a logical counter. The transaction which is created first or you can say older transactions are given high priority over new transactions.
44) What is Durability in DBMS?
In a DBMS system, Durability guarantees that once a transaction is committed to the Database, it will be stored in non-volatile memory to be safe against system failure.
45) What is a Catalog?
A catalog is a table containing information like each file’s structure, the type and storage format of all the data items, and various constraints on the data. The information stored in the catalog is known as metadata.
46) What is Storage Manager?
Storage Manager is a software module that provides the interface between the low-level data stored in the Database and application applications and queries submitted to the DBMS system.
47) What is Buffer Manager?
Buffer Manager is a program module responsible for fetching data from disk storage into main memory and determining what data to cache in memory.
48) What is QBE?
Query-by-example represents a graphical approach for accessing information in a database using query templates called skeleton tables.
QBE is used by entering example values directly into a query template to represent what is to be achieved.
49) What is Identity?
Identity is a column that automatically generates numeric values. It is also known as an auto number. A start and increment value can be set.
However, most DBMS leave these at 1.
50) What is a Trigger?
It is a code associated with insert, update or delete operations. It is executed automatically whenever the associated query is executed on a table. This code helps maintain integrity in the Database.
Correlated subqueries are executed for each row of the outer query. It is also known as a nested query, that is, a query that is embedded within another query.
52) What is a non-clustered index?
Non-clustered indexes store the data at one location and the indices at another. It contains pointers to the location of that data. There can be many non-clustered indexes within a single table since an index in a non-clustered index is stored in different locations.
53) What is a Clustered index?
Cluster indexes sort the rows of data in the table according to their fundamental values. In the DBMS system, there is only one clustered index per table.
A clustered index helps the DBMS system to define the order in which data is stored in the table. Therefore, there can be only a single clustered index for every table.
54) What is a Unique Key?
A unique key consists of a group of one or more fields or columns of a table that uniquely identifies each record in a database.
It is the same as a primary key but can accept one null value for a table column. It does not have identical values. There are some tables whose foreign keys refer to unique constraints.
55) What is Static SQL?
Static SQL is the SQL (Structure query language) statements embedded or hardcoded in the application, and they do not change at runtime. The process for data access is predetermined, hence swifter and more efficient.
56) What is Dynamic SQL?
In a Dynamic SQL database, SQL statements are generated by the application at runtime, where the user is empowered to create queries.
You can build your query at runtime. It is slower than static SQL as the query is compiled at runtime.
57) What is Relational Calculus?
Relational Calculus is a non-procedural query language. It uses mathematical predicate calculus. Therefore, its main focus is on what to do with the relations (tables) rather than how to do it.
58) What is BI?
Business Intelligence refers to processes, architectures, and technologies that transform raw data into meaningful information. As a result, profitable business actions are driven. It is a software suite to transform data into actionable intelligence and knowledge.
59) What is Network Model in DBMS?
The Network Model helps each child to have multiple parents. You can use it to model more complex relationships, such as the many-to-many relationship between orders and parts. In this DBMS model, entities are organized in a graph that can be accessed through several paths.
60) What are Temporary Tables? When are they useful?
Temporary tables exist for a particular session, or their data persists throughout the transaction. These tables are commonly used to support specialized rollups and specific application processing requirements.
Initially, no space is allocated to a temporary table, but as rows are inserted, space will be dynamically allocated.
