AI-Mock-Interviewer/PDF_Extracted_Data huggingface dataset:
Question: 14. What do normalization and denormalization mean?
Answer: Normalization is breaking up data into numerous tables to reduce duplication. Normalization allows for more efficient storage space and makes maintaining database integrity . Denormalization is the reversal of normalization, in which tables that have been normalized are combined into a single table to speed up data retrieval. By reversing the normalization,  the JOIN operation allows us to produce a denormalized data representation.
Question: 1. What are the various characteristics of a relational database management system (RDBMS)?
Answer: Name: Each relation should have a distinct name from all other relations in a relational database. Attributes: An attribute is a name given to each column in a relation. Tuples: Each row in a relation is referred to as a tuple. A tuple is a container for a set of attribute values.
Question: 2. What is the E-R Model, and how does it work?
Answer: The E-R model stands for Entity-Relationship. The E-R model is based on a real-world environment that consists of entities and related objects. A set of characteristics is used to represent entities in a database.
Question: 3. What does an object-oriented model entail?
Answer: The object-orien ed paradigm is built on the concept of collections of items. Values are saved in instance variables within an object and stored. Classes are made up of objects with the same values and use the same methods.
Question: 4. What are the three different degrees of data abstraction?
Answer: Physical level: This is the most fundamental level of abstraction, describing how data is stored. Logical level: The logical level of abstraction explains the types of data recorded in a database and their relationships. View level: This is the most abstract level, and it describes the entire database.
Question: 5. What are the differ ences between Codd's 12 Relational Database Rules?
Answer: Edgar F. Codd presented a set of thirteen rules (numbered zero to twelve) that he called Codd's 12 rules. Codd's rules are as follows: Rule 0: The system must meet Relational, Database, and Management Systems requirements. Rule 1: The information rule: Every piece of data in the database must be represented uniquely , most notably name values in column locations inside a distinct table row . Rule 2: The second rule is the assured access rule, which states that all data must be ingressive. Every scalar value in the database must be correctly/logically addressable. Rule 3: Null values must be treated consistently: The DBMS must allow each tuple to be null. Rule 4: Based on the relation al paradigm, an active online catalog (database structure): The system must provide an online, relational, or other structure that is ingressive to authorized users via frequent queries. Rule 5: The sublanguage of complete data: The system must support at least one relational language that meets the following criteria:1. That has a linear syntax 2. That can be utilized interactively as well as within application applications. 3. Data definition  (DDL), data manipulation (DML), security and integrity restri ctions, and transaction management activities are all supported (begin, commit, and roll back). Rule 6: The view update rule: The system must upgrade any views that theoretically improve. Rule 7: Insert, update, and delete at the highest level: The system must support insert, update, and remove operators at the highest level. Rule 8: Physical data independence: Changing the physical level (how data is stored, for example, using arrays or linked lists) should not change the application. Rule 9: Logical data independence: Changing the logical level (tables, columns , rows, and so on) should not need changing the application. Rule 10: Integrity independence: Each application program's integrity restrictions must be recognized and kept separately in the catalog. Rule 11: Distribution independence: Users should not see how pieces of a database are distributed to multiple sites. Rule 12: The nonsubversion rule: If a low-level (i.e., records) interface is provided, that interface cannot be used to subvert the system.
Question: 6. What is the definition of normalization? What, therefore, explains the various normalizing forms?
Answer: Database normalization is a method of structuring data to reduce data redundancy . As a result, data consistency is ensured. Data redundancy has drawbacks, including wasted disk space, data inconsistency , and delayed DML (Data Manipulation Language) searches. Normalization forms include 1NF , 2NF , 3NF , BCNF , 4NF , 5NF , ONF , and DKNF .1.1NF: Each column's data should contain atomic number multiple values separated by a comma. There are no recurring column groupin gs in the table, and the main key is used to identify each entry individually . 2.2NF: – The table should satisf y all of 1NF's requirements, and redundant data should be moved to a separate table. Furthermore, it uses foreign keys to construct a link between these tables. 3.3NF: A 3NF table must meet all of the 1NF and 2NF requirements. There are no characteristics in 3NF that are partially reliant on the main key .
Question: 7. What are primary key, a foreign key, a candidate key, and a super key?
Answer: The main key is the key that prevents duplicate and null values from being stored. A primary key can be specified at the column or table level, and per table, only one primary key is permitted. Foreign key: a foreign key only admits values from the linked column, and it accepts null or duplicate values. It can be classified as either a column or a table level, and it can point to a column in a unique/primary key table. Candidate Key: A Candidate key is the smallest super key; no subset of Candidate key qualities may be used as a super key . A super key: is a collection of related schema characteristics on which all other schema elements are partially reliant. The values of super key attributes cannot be identical in any two rows.
Question: 8. What ar e the various types of indexes?
Answer: The following are examples of indexes: Clustered index: This is where data is physically stored on the hard drive. As a result, a database table can only have one clustered index. Non-clustered index: This index type does not define physical data but defines logical ordering. B-Tree or B+ trees are commonly used for this purpose.
Question: 9. What are the benefits of a relational database management system (RDBMS)?
Answer: Controlling Redundancy is the answer . Integrity is something that can be enforced. •It is possible to prevent inconsistency . •It's possible to share data. •Standards are enforceable.
Question: 10. What are some RDBMS subsystems?
Answer: RDBMS subsystems are Language processing, Input-output, security , storage managem ent, distribution control,  logging and recovery , transaction control, and memory management.
Question: 11. What is Buffer Manager , and how does it work?
Answer: The Buffer Manager collects data from disk storage and chooses what data should be stored in cache memory for speedier processing. MYSQL MySQL is a relational database management system that is free and open- source (RDBMS ). It works both on the web and on the server . MySQL is a fast, dependable , and simple database, and it's a free and open-source program. MySQ L is a database management system that runs on many systems and employs standard SQL. It's a SQL database management system that's multithreaded and multi-user . Tables are used to store information in a MySQL database. A table is a set of columns and rows that hold linked information. MySQL includes standalone clients that allow users to communicate directly with a MySQL database using SQL. Still, MySQL is more common to be used in conjunction with other programs to create applications that require relational database functionality. Over 11 million people use MySQL.
Question: 1. What exactly is MySQL?
Answer: MySQL is a scalable web server database management system, and it can expand with the website. MySQL is by far the most widely used open- source SQL database management system, developed by Oracle Corporation.
Question: 2. What are a few of the benefits of MySQL?
Answer: •MySQL is a flexible database that operates on any operating system. •MySQL is focused on performance. •SQL at the Enterprise Level MySQL had been deficient in sophisticated functionality like subqueries, views, and stored procedures for quite some time. •Indexing and Searching of Full-T ext Documents •Query Caching: This significantly improves MySQL's performance. •Replication: A MySQL server may be copied on another , with many benefits. •Security and configuration
Question: 3. What exactly do you mean when you say "databases"?
Answer: A databa se is a structured collec tion of data saved in a computer system and organized to be found quickly . Information may be quickly found via databases.
Question: 4. What does SQL stand for in MySQL?
Answer: SQL stands for Structured Query Language in MySQL. Other databases, such as Oracle and Microsoft SQL Server , also employ this language. To submit queries from a database, use instructions like the ones below: It's worth noting that SQL doesn't care about the case. However , writing SQL keywords in CAPS and other names and variables in a small case is agood practice.
Question: 5. What is a MySQL database made out of?
Answer: A MySQL database comprises one or more tables, each with its own set of entries or rows. The data is included in numerous columns or fields inside these rows.
Question: 6. What ar e your options for interacting with MySQL?
Answer: You may communicate with MySQL in three dif ferent ways: Via a web interface, Using a command line, Through a programming language.
Question: 7. What are MySQL Database Queries, and How do I use them?
Answer: An inquiry is a request or a precise question. A database may be queried for specific information, and a record returned.
Question: 8. In MySQL, what is a BLOB?
Answer: The abbreviation BLOB denote s a big binary object, and its purpose is to store a changeable amount of information. There are four dif ferent kinds of BLOBs: TINYBLOB, MEDIUMBLOB, BLOB, LONGBLOB. A BLOB may store a lot of information. Documents, photos, and even films are examples. If necessary , you may save the whole manuscript as a BLOB file.
Question: 9. What is the procedure for adding users to MySQL?
Answer: By executing the CREATE command and giving the required credentials, you may create a User . Consider the following scenario: CREATE USER 'testuser' WITH' sample password' AS IDENTIFIER.
Question: 10. What exactly are MySQL's "Views"?
Answer: A view in MySQL is a collection of rows that are returned when a certain query is run. A 'virtual table' is another name for this. Views make it simple to find out how to make a query available via an alias. Views provide the following advantages: Security, Simplicity, Maintainability
Question: 11. Define MySQL Triggers?
Answer: A trigger is a job that runs in reaction to a predefined database  event, such as adding a new record to a table. This event entails entering, altering, or removing table data, and the action might take place before or immediately after any such event. Triggers serve a variety of functions, including: •Validation •Audit T rails •Referential integrity enforcement
Question: 12. In MySQL, how many triggers are possible?
Answer: There are six triggers that may be used in the MySQL database: After Insert, Before Insert, Before Delete, Before Update, After Update, After Delete.
Question: 13. What exactly is a MySQL server?
Answer: The server, mySQLd, is the heart of a MySQL installation; it handles all database and table management.
Question: 14. What are the different types of MySQL relationships?
Answer: In MySQL, there are three types of relationships:•One-o-One: When two things have a one-to-one relationship, they are usually included as columns in the same table. •One-to-Many: When one row in one database is linked to many rows in another table, this is known as a one-to-many (or many -to-one) connection. •Many-to-Many: Many rows in one table are connected to many rows in another table in a many-to-many connection. Add a third table with the same key column as the other tables 29 to establish this link.
Question: 15. What is MySQL Scaling?
Answer: In MySQL, scaling capacity refers to the system's ability to manage demand, and it's helpful to consider load from a variety of perspectives, including: Quantity of information, Amount of users, Size of related datasets, User activity
Question: 16. What is SQL Sharding?
Answer: Sharding divides huge tables into smaller portions (called shards) distributed acros s different servers. The benefit of sharding is that searches, maintenance, and other operations are quicker because the shard ed database is typically much smaller than the original.
Question: 1. What are constraints?
Answer: A constraint is an attribute of a table column that conducts data validation. Constraints help to ensure data integrity by prohibiting the entry of incorrect data.
Question: 2. What do you mean when you say "data integrity"?
Answer: The consistency and correctness of data kept in a database are data integrity .
Question: 3. Is it possible to add constraints to a table that alr eady contains data?
Answer: Yes, but it also depends on the data. For example, if a column contains null values and adds a not-null constraint, you must first replace all null values with some values.
Question: 4. Can a table have more than one primary key?
Answer: No table can only have one primary key
Question: 5. What is the definition of a foreign key?
Answer: In one table, an FK refers to a PK in another . It prohibits any operations that might break the linkages betwee n tables and the data values they represent. FKs are used to ensure that referential integrity is maintained.
Question: 6. What is the difference between primary and unique key constraints?
Answer: A null value will be allowed if the constraint is unique. A unique constraint will allow just one null value if a field is nullable. SQL Server allows for several unique constraints per table, but MySQL only allows for a single primary key .
Question: 7. Is it possible to use Unique key restrictions across multiple columns?
Answer: Yes! Unique key constraints can be imposed on a composite of many fields to assure record uniqueness. Example: City + State in the StateList table.
Question: 8. When you add a unique  key constraint, which index does the database construct by default?
Answer: A nonclustered index is constructed when you add a unique key constraint.
Question: 9. What does it mean when you say "default constraints"?
Answer: When no value is supplied in the Insert or Update statement, a default constraint inserts a value in the column.
Question: 10. What kinds of data integrity are there?
Answer: There are three types of integrity in relational databases. Entity Integrity (unique constraints, primary key), Domain Integrity (check constraints, data type).
Question: 1. What exactly is an index?
Answer: An index is a database object that the SQL server uses to improve query performance by allowing query access to rows in the data table. We can save time and increase the speed of database queries and applications by employing indexes. When construct ing an index on a column, SQL Server creates a second index table. When a user tries to obtain data from an existin g table that relies on the index table, SQL Server goes straight to the table and quickly retrieves the data. 250 indexes may be used in a table. The index type describes how SQL Server stores the index internally .
Question: 2. Why are indexes required in SQL Server?
Answer: Queries employ indexes to discover data from tables quickly . Tables and views both have indexes. The index on a table or view is quite similar to the index in a book. If a book doesn't contain an index and we're asked to find a certain chapter , we'll have to browse through the whole book, beginning with the first page. If we have the index, on the other hand, we look up the chapter's page number in the index and then proceed to that page number to find the chapter . Table and View indexes can help the query discover data fast in the same way. In reality , the presence of the appropriate indexes may significantly enhance query performance. If there is no index to aid the query , the query engine will go over each row in the table from beginning to end. This is referred to as a T able Scan, and the performance of a table scan is poor .
Question: 3. What are the different types of indexes in SQL Server?
Answer: Clustered Index Non-Clustered Index
Question: 4. What is a Clustered Index?
Answer: In the case of a clustered index,  the data in the index table will be arranged the same way as the data in the real table. The index, for example, is wher e we discover the beginning of a book. The term "clustered table" refers to a table that has a clustered index. The data rows in a table witho ut a clustered index are kept unordered. A table can only have one clustered index, which is constructe d when the table's main key constraint is invoked. A clustered index determines the physical order of data in a table. As a result, a table can only have one clustered index.
Question: 5. What is a non-clustered index?
Answer: In a non-clustered index, the data in the index table will be organized differently than the data in the real database. A non-cluster ed index is similar to a textbook index. The data is kept in one location, while the index is kept in another . The index will contain references to the data's storage place. A table can contain more than one non-clustered index since the non- clustered index is kept independently from the actual data, similar to how a book can have an index by chapters at the beginning and another index by common phrases at the conclusion. The data is stored in the index  in ascending or descending order of the index key, which  has no bearing on data storage in the table. We can define a maximum of 249 non clustered indexes in a database.
Question: 6. In SQL Serv er, what is the difference between a clustered and a non- clustered index?
Answer: One of the most common SQL Server Indexes Interview Ques tions is this one. Let's look at the differences. There can only be one clustered index per table, although several non-clustered indexes can be. The Clustered Index is quicker  than the Non-Clustered Index by a little margin. When a Non-Clustered Index is used, an extra lookup from theNon-Clustered Index to the table is required to retrieve the actual data. A clustered index defines the row storage order in the database and does not require additional disk space. Still, a non-clustered index is kept independently from the table and thus requires additional storage space. A clustered index is a sort of index that reorders the actual storage of entries in a table. As a result, a table can only have one clustered index. A non- clustered index is one in which  the logical order of the index differs from the physical order in which the rows are written.
Question: 7. What is a SQL Server Unique Index?
Answer: If the "UNIQUE" option is used to build the index, the column on which the index is formed will not allow duplicate values, acting as a unique constraint. Unique clustered or unique non-clustered constraints are both possible. If clustered or non-clustered is not provided when building an index, it will be non-clustered  by default. A unique index is used to ensure that key values in the index are unique.
Question: 8. When does SQL Server make use of indexes?
Answer: SQL Server utilizes a table's indexes if the select, update, or delete statement includ ed a "WHERE" condition and the where condition field was an indexed column. If an "ORDER BY" phrase is included in the select statement, indexes will be used as well. Note:  When SQL Server searches the database for information, it first determines the optimum execu tion plan for retrieving the data and then employs that plan, a full-page scan or an index scan.
Question: 9. When should a table's indexes be created?
Answer: If a table column is regularly used in a condition or order by clause, we must establish an index on it. It is not recommended that an index be created for each column since many indexes might reduce database performance. Any change to the data should be reflected in all index tables.
Question: 10. What is the maximum number of cluster ed and non-clustered indexes per table?
Answer: Clustered Index:  Each table has only one Clustered Index. A clustered index stores all of the data for a single table, ordered by the index key. The Phone Book exemplifies the Clustered Index. Non-Cluster ed Index:  Each table can include many Non-Clustered Indexes. A Non-Clustered Index is an index found in the back of a book. 1 Clustered Index + 249 Nonc lustered Index = 250 Index in SQL Server 2005 1 Clustered Index + 999 Nonc lustered Index = 1000 Index in SQL Server 2008.
Question: 11. Clustered or non-clustered index, which is faster?
Answer: The Clustered Index is quicker  than the Non-Clustered Index by a little margin. When a Non-Clustered Index is used, an extra lookup from the Non-Clustered Index to the table is required to retrieve the actual data.
Question: 12. In SQL Server, what is a Composite Index? What are the benefits of utilizing a SQL Server Comp osite Index? What exactly is a Covering Query?
Answer: A composite index is a two-or -more-column index, and composite indexes can be both clustered and non-clustered. A covering query is one in which all of the information can be acquired from an index. A clustered index always covers a query if chosen  by the query optimizer because  it contains all the data in a table.
Question: 13. What are the various index settings available for a table?
Answer: One of the following index configurations can be applied to a table: There are no indexes. A clustered index, Many non-clustered indexes and a clustered index, A non-clustered index, Many non-clustered indexes.
Question: 14. What is the table's name with neither a Cluster nor a Noncluster Index? What is the purpose of it?
Answer: Heap or unindex ed table Heap is the name given to it by Microsoft Press Books and Book On-Line (BOL). A heap is a table that does not have a clustered index and does not have pointers connecting the pages. The only structures that connect the pages in a table are the IAM pages. Unindexed table s are ideal for storing data quickly . It is often preferable to remove all indexes from a table  before doing a large number of inserts and then to restore those indexes.
Question: 1. What is data integrity?
Answer: The total correctness, completeness, and consistency of data are known as data integrity . Data integrity also refers to the data's safety and security in regulatory compliance, such as GDPR compliance. It is kept up-to-date by a set of processes, regulations, and standards that were put in place during the design phase. The information in a database will stay full, accurate, and dependable no matter how long it is held or how often it is accessed if the data integrity is protected. The importance of data integrity in defending oneself against data loss or a data leak cannot  be overstated: you must first guarantee that internal users are handling data appropriately  to keep your data secure from harmful outside influences. You can ensure that sensitive data is never miscategorized or stored wrongly by implementing suitable data validation and error checking, therefore exposing you to possible danger .
Question: 2. What ar e data Integrity Types?
Answer: There must be a proper understanding of the two forms of data integrity , physical and logical, for mainta ining data integrity . Both hierarchical andrelational databases are collections of procedures and methods that maintain data integrity .