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View Serializable is a correctness criterion in database management systems that ensures that the final result of executing concurrent transactions is the same as if they were executed one after the other. This property helps maintain data consistency and ensures that the database remains in a consistent state despite concurrent transaction execution. Transactions are said to be view serializable if their interleaved execution produces the same results as if they were executed sequentially.
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What are three types of dbms?
Hierarchical DBMSNetwork DBMSRelational DBMS
Show the difference bw 3-levels of data abstraction in DBMS?
The three levels of data abstraction in a DBMS are physical, logical, and view. Physical level: Describes how data is stored in the database, including details like data storage and access paths. Logical level: Focuses on the structure of the data in the database, including schemas, tables, and relationships. View level: Represents how users view the data, providing a customized and simplified representation of the data to different user groups.
What is data integration in dbms?
Data integration in DBMS refers to the process of combining data from different sources and formats into a unified view for analysis and decision-making. It involves mapping and transforming data to ensure compatibility and consistency across multiple systems. Data integration helps organizations make better informed decisions by providing a comprehensive and accurate view of their data assets.
What is view of data in dbms?
In a database management system (DBMS), a view is a virtual table derived from one or more base tables. It allows users to query or manipulate data without directly accessing the underlying tables, providing a layer of abstraction and security. Views can simplify complex queries, hide sensitive information, and provide a consistent interface to the data.
What is the fullform of DBMS?
The full form of DBMS is Database Management System.
Serial schedule differs serializable schedule in dbms?
Serial schedules are the schedules during which all statements in a transaction are executed consecutively. Serializable schedule is a schedule that is equivalent to a serial schedule
What is the difference between conflict equivalence and view equivalence of dbms?
Conflict equivalence- Two schedules are conflict equivalent if the order of any two conflicting operations is same in both the two schedules. View equivalence- Two schedules are view equivalent if - 1) Both the schedules have same set of transactions. 2) If in a schedule a read operation r1[X] of transaction T1 reads the value of X written by a write operation w2[x] of transaction T2 or reads the original value of x,then this must also be the case in the other schedule. 3)If operation w3[Y] of a transaction is the last operation to write the value of Y in schedule S then it must also be the last transaction in the other schedule to do so. All conflict serializable schedules are view serializable. But all view serializable schedules are not conflict serializable.
What in java is not serializable?
Objects that do not implement Serializable.
What is a snapshot IN DBMS?
A DBMS snapshot in Oracle can also be referred to as a materialized view. Basically a snapshot is a refreshable view that can be refreshed on command or commit.
Can you serialize the ArrayList class in Java?
The ArrayList class itself is serializable and will serialize if it contains only serializable objects.If, however, you add non-serializable objects into the list then it will not serialize, but will throw a NotSerializableException.
What is serializable class in JAVA?
The serializable interface is used to perform the serialization action. Serialization is the process by which the contents of an object are written to any form of storage - say a flat file. This data stored in the flat file can be de-serialized at any time to create the object. Ex: public class Test implements Serializable { … //lots of code }
What are highlights of DBMS?
NA_ what are highlights of advanced DBMS what are highlights of advanced DBMS what are highlights of advanced DBMS
Is java DBMS?
no, Java is not dbms.. Java is a programming language Dbms is database
Is SQL DBMS or RDBMS?
dbms
What are three types of dbms?
Hierarchical DBMSNetwork DBMSRelational DBMS
Will view drop if table drop?
If the dropped table is a base table for a view , then dbms like oracle invalidates these dependent views but does not drop them. But you cannot use these unless you re-create the table.
Mapping in DBMS architecture?
We know that three view-levels are described by means of three schemas. These schemas are stored in the data dictionary. In DBMS, each user refers only to its own external schema. Hence, the DBMS must transform a request on. a specified external schema into a request against conceptual schema, and then into a request against internal schema to store and retrieve data to and from the database. The process to convert a request (from external level) and the result between view levels is called mapping. The mapping defines the correspondence between three view levels. The mapping description is also stored in data dictionary. The DBMS is responsible for mapping between these three types of schemas. There are two types of mapping. (i) External-Conceptual mapping (ii) Conceptual-Internal mapping External-Conceptual Mapping An external-conceptual mapping defines the correspondence between a particular external view and the conceptual view. The external-conceptual mapping tells the DBMS which objects on the conceptual level correspond to the objects requested on a particular user's external view. If changes are made to either an external view or conceptual view, then mapping must be changed accordingly. Conceptual-Internal Mapping The conceptual-internal mapping defines the correspondence between the conceptual view and the internal view, i.e. database stored on the physical storage device. It describes how conceptual records are stored and retrieved to and from the storage device. This means that conceptual-internal mapping tells the DBMS that how the conceptual! records are physically represented. If the structure of the stored database is changed, then the mapping must be changed accordingly. It is the responsibility of DBA to manage such changes.
