Different companies have a different approach to their interviewing process.

Dp alt mode android

Some would be concentrating on work experience and knowledge; others might focus on personality, while the rest fall somewhere in between. Therefore, finding and learning from different interview questions and answers can help see different perspectives of what might be most important in different marketplaces. Moreover, a table can have multiple non-cluster indexes, but only 1 single clustered one. This happens when the character is unknown or unavailable.

Another thing worth noting is that the command can be used on various platforms. Que What are variables of SQL? Explanation: In SQL, there are two different variables:. Explanation: A recursive stored procedure is a procedure that will make the code calls itself until specific boundary condition is reached.

This is a productivity type of thing, that allows programmers to use the same code a number of times. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below. Writing code in comment? Please use ide. Explanation: Indexes help retrieve information from the database faster and with higher efficiency. Check out this Author's contributed articles.

Load Comments.DBMS is a collection of programs that facilitates users to create and maintain a database.

advanced dbms important questions

In other words, DBMS provides us an interface or tool for performing different operations such as the creation of a database, inserting data into it, deleting data from it, updating the data, etc.

DBMS is a software in which data is stored in a more secure way as compared to the file-based system. Using DBMS, we can overcome many problems such as- data redundancy, data inconsistency, easy access, more organized and understandable, and so on. A Database is a logical, consistent and organized collection of data that it can easily be accessed, managed and updated.

Databases, also known as electronic databases are structured to provide the facility of creation, insertion, updating of the data efficiently and are stored in the form of a file or set of files, on the magnetic disk, tapes and another sort of secondary devices.

Database mostly consists of the objects tablesand tables include of the records and fields. Fields are the basic units of data storage, which contain the information about a particular aspect or attribute of the entity described by the database. DBMS is used for extraction of data from the database in the form of the queries.

The collection of database and DBMS software together is known as a database system. Through the database system, we can perform many activities such as. The data can be stored in the database with ease, and there are no issues of data redundancy and data inconsistency. The data will be extracted from the database using DBMS software whenever required. So, the combination of database and DBMS software enables one to store, retrieve and access data with considerate accuracy and security.

The Checkpoint is a type of mechanism where all the previous logs are removed from the system and permanently stored in the storage disk. There are two ways which can help the DBMS in recovering and maintaining the ACID properties, and they are- maintaining the log of each transaction and maintaining shadow pages.

So, when it comes to log based recovery system, checkpoints come into existence. Checkpoints are those points to which the database engine can recover after a crash as a specified minimal point from where the transaction log record can be used to recover all the committed data up to the point of the crash. A checkpoint is like a snapshot of the DBMS state.

Using checkpoints, the DBMS can reduce the amount of work to be done during a restart in the event of subsequent crashes. Checkpoints are used for the recovery of the database after the system crash. Checkpoints are used in the log-based recovery system. When due to a system crash we need to restart the system then at that point we use checkpoints. So that, we don't have to perform the transactions from the very starting.Here are some complex SQL interview problems that are for people who are looking for more advanced and challenging questions, along with the answers and complete explanations.

Try to figure out the answer to the questions yourself before reading the answers. We want to retrieve the names of all salespeople that have more than 1 order from the tables above. You can assume that each salesperson only has one ID. If that is the case, then what if anything is wrong with the following SQL? There is definitely something wrong with the SQL above, and it is probably something that most beginner SQL programmers may not notice.

The problem is that the SQL Standard says that we can not select a column that is not part of the group by clause unless it is also contained within an aggregate function. The most important thing you should take out of this discussion is understanding exactly why we get that error, and how to avoid it. There is a good reason for the error — read on to understand why.

As the error above suggests, we can fix the error by either wrapping the Name column inside an aggregate function or adding it to the Group By clause. So if we want to write SQL that complies with the standard, then we could write something like this by adding the Name column to the Group By:.

We could also fix the problem by putting the Name column in any aggregate function, and then simply make that a part of our select statement.

Lg stylo 4 firmware download

We chose to use the MAX aggregate function, but any other aggregate would work just fine as well:. So, now you understand how to fix the error — but do you understand why it is a problem in the first place? Well, you should — because that is the most important thing to understand! You probably know what aggregate functions in SQL are — we used one in the example above.

In case you forgot, aggregate functions are used to perform a mathematical function on the values inside a given column, which is passed into the aggregate function.

DBMS Interview Questions

Here are some of the commonly used aggregate functions:. Subscribe to our newsletter for more free interview questions. Since we group by city, will it return the highest hourly rate for each city? Will it return the hourly rate as a distinct list, so those 2 guys making 11 dollars an hour will have the 11 returned only once? The problem here is that we do not know what will be returned because we are not specific enough with what we are asking for in the SQL!

If what we are asking for is not specific enough, then the SQL processor will not know what to return.What are the disadvantages of File processing? What is DBMS? Explain advantages and disadvantages of DBMS. What are the different components of DBMS? Explain different types of databases.

Explain Data anomalies. What are the functions of DBMS? Data Models.

New issue on github

Explain the importance of Database models. Explain Hierarchical Data Model. Explain Network Data Model. Explain Relational Database Model. Explain Entity Relationship Model. Explain The Object Oriented Model. Explain Data abstraction or 3 schema architecture. Relatio nal Database Model. What is a Table and explain its characteristics?

Commonly asked DBMS interview questions | Set 1

Explain different types of keys available in Relational Model. Explain Database Integrity rules. Explain different Relational set operators. Explain different types of joins. Explain basic notations of ER diagram. What are the different types of Entities? Explain different types of Attributes. Explain degree of relationships. What are the database design challenges? What is an entity supertype and subtype, and why is it used?

What is a specialization hierarchy? What is a subtype discriminator?Database management system DBMS is one of the key software in the IT industry for managing or creating any databases in the system. DBMS mainly provides a big utility to the programmer or specific user for creating, updating, deleting or storing data by using some systematic way. It is true that every interview is different as per the different job profiles.

These interview questions are divided into two parts are as follows:. One of the key purposes of using the application system revolves with varieties of data available in the industry. This is one of the key systems which helps users for storing multiple kinds of data in a systematic way, define the characteristics of data, retrieve smoothly whenever require an update that specific data on that corresponding database properly.

Answer: The database can be defined in varieties approach. In a simple way, we can say the database is mainly handling the collection of multiple types of data, storing the same in define organize way, give key facility for the user for retrieving the same smoothly. It also can able to manage proper accessing of a specific user on the data and ensuring uploading critical data in a proper manner.

Normalization is one of the key properties specifically for the relational database management system RDBMS. It is one of the important processes for analyzing multiple relational schemas where they have some dependency based on their different functional point of view and have to maintain one primary key for defining some of the key properties. Properties are defining below:.

Answer: SQL is basically called the structured query language. One of the main purposes of using the same is to interact with one of the specifically define the relational database in some form of inserting, deleting or updating data from the defined database. Answer: Primary key and Foreign key is mainly using for any kind of relational database management system.

The primary key is basically ensuring the integrity of one specific table entire data security, ensuring one unique identification of that specific record in that database table. Whereas foreign key is mainly maintaining one relation of one specific column of that table with one another table specific column where another table specific column will be the primary key of that table.

Answer: Some of the key differences between primary key and a unique key are defined below:. Some popular test cases in the current IT industry. A subquery is one of the concepts of writing query inside some other query. It also has one popular name called inner query which actually belonging under some outer query. Differences are:.

advanced dbms important questions

Truncate : truncating entire data available in the database, but not deleting the structure of the table. You may also look at the following articles to learn more —.

advanced dbms important questions

Your email address will not be published. Forgot Password? Popular Course in this category. Course Price View Course. Leave a Reply Cancel reply Your email address will not be published.

Free Data Science Course. By continuing above step, you agree to our Terms of Use and Privacy Policy. Login details for this Free course will be emailed to you. Please provide your Email ID.A prearranged collection of figures known as data is called database. Database Management Systems DBMS are applications designed especially which enable user interaction with other applications. Edgar F. Codd proposed the relational model in A database language may also incorporate features like: DBMS-specific Configuration and management of storage engine Computations to modification of query results by computations, like summing, counting, averaging, grouping, sorting and cross-referencing Constraint enforcement Application Programming Interface 7 What do database languages do?

As special-purpose languages, they have: Data definition language Data manipulation language Query language 8 Define database model. A data model determining fundamentally how data can be stored, manipulated and organised and the structure of the database logically is called database model.

The various relationships of database are: One-to-one: Single table having drawn relationship with another table having similar kind of columns. One-to-many: Two tables having primary and foreign key relation.

Many-to-many: Junction table having many tables related to many tables. Organized data void of inconsistent dependency and redundancy within a database is called normalization. Advantages of normalizing database are: No duplicate entries Saves storage space Boasts the query performances. Boosting up database performance, adding of redundant data which in turn helps rid of complex data is called denormalization. Manipulating data in a database such as inserting, updating, deleting is defined as Data Manipulation Language.

DROP: It destroys an existing database, index, table or view. Its syntax is: DROP objecttype objectname. Full recordings of two tables is Union All operator. A distinct recording of two tables is Union. A database object which helps in manipulating data row by row representing a result set is called cursor.

They are: Dynamic: it reflects changes while scrolling. Static: doesn't reflect changes while scrolling and works on recording of snapshot.

Keyset: data modification without reflection of new data is seen.

All movie scripts

They types of cursor are: Implicit cursor: Declared automatically as soon as the execution of SQL takes place without the awareness of the user. A query contained by a query is called Sub-query. Group-clause uses aggregate values to be derived by collecting similar data. Functions which operate against a collection of values and returning single value is called aggregate functions 24 Define Scalar functions. Scalar function is depended on the argument given and returns sole value.

advanced dbms important questions

Restrictions that are applied are: Only the current database can have views. You are not liable to change any computed value in any particular view.Basically, out of my personal experience, there is not any specific way or formula to get through an Interview Process and it totally depends on you and the type of Interviewer. This article includes almost all the important DBMS interview questions, covering the basic concepts in simple terms along with examples for your easy understanding.

This is a system that allows its user to store the data, define it, retrieve it and update the information about the data inside the database. Explain by listing some of its major advantages. Answer: Normalization is the process of analyzing the relational schemas which are based on their respective functional dependencies and the primary keys in order to fulfill certain properties.

Q 7 Explain the concepts of a Primary key and Foreign Key. Answer: Primary Key is used to uniquely identify the records in a database table while Foreign Key is mainly used to link two or more tables together, as this is a particular field s in one of the database tables which are the primary key of some other table.

Example : There are 2 tables — Employee and Department. Q 8 What are the main differences between Primary key and Unique Key? Q 9 What is the concept of sub-query in terms of SQL? Answer: Sub-query is basically the query which is included inside some other query and can also be called as an inner query which is found inside the outer query. These 2 operations cannot be rolled back and so should be used only when necessary. These properties are very helpful in allowing a safe and secure way of sharing the data among multiple users.

Answer: A Subquery is also known as a nested query i. When a Subquery is executed for each of the rows of the outer query then it is termed as a Correlated Subquery. Example of Non-Correlated Subquery is:. Entity is an object, place or thing which has its independent existence in the real world and about which data can be stored in a database.

Top 50 DBMS Interview Questions and Answers - DBMS Interview Preparation - Edureka

Entity Type is a collection of entities that have the same attributes. Entity Set is a collection of entities of the same type. Answer: E-R model is known as an Entity-Relationship model in the DBMS which is based on the concept of the Entities and the relationship that exists among these entities.

Answer: This is basically a constraint which is useful in describing the relationship among the different attributes in a relation. This is the easiest form of the normalization process which states that the d omain of an attribute should have only atomic values. The objective of this is to remove the duplicate columns that are present in the table. Answer: This is used with the SQL queries to fetch specific data as per the requirements on the basis of the conditions that are put in the SQL.

This is very helpful in picking the selective records from the complete set of the records.

Kalmar oem parts

Q 24 How can you get the alternate records from the table in the SQL? Answer: If you want to fetch the odd numbers then the following query can be used:. Q 25 How is the pattern matching done in the SQL? Q 27 What are different types of joins in SQL? Answer: Trigger is one of the very important codes or programs which get executed automatically in response to the events that occur in a table or a view.

Answer: Stored Procedure is a group of SQL statements in the form of a function that has some unique name and is stored in relational database management systems RDBMS and can be accessed whenever required.

Answer: RDBMS is the Relational Database Management System which contains data in the form of the tables and data is accessed on the basis of the common fields among the tables. I hope that this article would have provided you a great insight regarding the questions that can be asked during an interview and by now you should have gained the confidence to handle your interview process.

Last Updated: April 16,

thoughts on “Advanced dbms important questions

Leave a Reply

Your email address will not be published. Required fields are marked *