Database System Concepts
... Failures may leave database in an inconsistent state with partial updates carried out Example: Transfer of funds from one account to another should either complete or not happen at all Concurrent access by multiple users Uncontrolled concurrent accesses can lead to inconsistencies Example: T ...
... Failures may leave database in an inconsistent state with partial updates carried out Example: Transfer of funds from one account to another should either complete or not happen at all Concurrent access by multiple users Uncontrolled concurrent accesses can lead to inconsistencies Example: T ...
Database System Concepts - Department of Systems Engineering
... Failures may leave database in an inconsistent state with partial updates carried out Example: Transfer of funds from one account to another should either complete or not happen at all Concurrent access by multiple users Uncontrolled concurrent accesses can lead to inconsistencies Example: T ...
... Failures may leave database in an inconsistent state with partial updates carried out Example: Transfer of funds from one account to another should either complete or not happen at all Concurrent access by multiple users Uncontrolled concurrent accesses can lead to inconsistencies Example: T ...
Discovering Robust Knowledge from Databases that Change
... address the issue of database changes. This paper formalizes the notion of robustness of a rule r in a given db state d as The robustness estimation approach estimates probabilities of rule invalidating transactions in a relational db environment. This approach decomposes the probability of a tr ...
... address the issue of database changes. This paper formalizes the notion of robustness of a rule r in a given db state d as The robustness estimation approach estimates probabilities of rule invalidating transactions in a relational db environment. This approach decomposes the probability of a tr ...
CS206 --- Electronic Commerce
... Isolation Level Is Personal Choice Your choice, e.g., run serializable, affects only how you see the database, not how others see it. Example: If Joe Runs serializable, but Sally doesn’t, then Sally might see no prices for Joe’s Bar. i.e., it looks to Sally as if she ran in the middle of Joe’s ...
... Isolation Level Is Personal Choice Your choice, e.g., run serializable, affects only how you see the database, not how others see it. Example: If Joe Runs serializable, but Sally doesn’t, then Sally might see no prices for Joe’s Bar. i.e., it looks to Sally as if she ran in the middle of Joe’s ...
Database Projects in Visual Studio
... Entity containing all of the MSSQL database and instance objects, such as tables, views, etc DAC provides: ...
... Entity containing all of the MSSQL database and instance objects, such as tables, views, etc DAC provides: ...
Practical Database Design and Tuning
... attributes from two or more tables are frequently needed together. →For the given set of tables, there may be alternative design choices, all of which achieve 3NF or BCNF. One may be replaced by the other. →A relation of the form R(K, A, B, C, D, …) that is in BCNF can be stored into multiple tables ...
... attributes from two or more tables are frequently needed together. →For the given set of tables, there may be alternative design choices, all of which achieve 3NF or BCNF. One may be replaced by the other. →A relation of the form R(K, A, B, C, D, …) that is in BCNF can be stored into multiple tables ...
Preventing Transaction Logs From Filling Up
... essential to keeping the database in working order. Not only does the database need to be backed up but the accompanying transaction log needs to be backed up as well. Failure to back up the transaction log can cause the database to become inoperable due to the file growing too large. This document ...
... essential to keeping the database in working order. Not only does the database need to be backed up but the accompanying transaction log needs to be backed up as well. Failure to back up the transaction log can cause the database to become inoperable due to the file growing too large. This document ...
17_backup
... • Mirroring is the practice of replicating transactions onto two different storage systems as they occur • Some DBMS will automatically implement mirroring • Can also be implemented at the application level – Create two connection objects to different DB – Execute each Update/Insert/Delete against b ...
... • Mirroring is the practice of replicating transactions onto two different storage systems as they occur • Some DBMS will automatically implement mirroring • Can also be implemented at the application level – Create two connection objects to different DB – Execute each Update/Insert/Delete against b ...
Performance evaluation of parallel transaction processing in shared
... Manipulation Language) statements submitted to the back-end system may originate directly from the end-user (ad-hoc queries) or from application programs running on workstations or mainframes. Some database machines (e.g. EDS) support the management of application programs (consisting of multiple DM ...
... Manipulation Language) statements submitted to the back-end system may originate directly from the end-user (ad-hoc queries) or from application programs running on workstations or mainframes. Some database machines (e.g. EDS) support the management of application programs (consisting of multiple DM ...
Logical Design of Audit Information in Relational Databases
... mechanisms to achieve these objectives. In addition to the actual recording of all events that take place in the database, a logical structure needs to be imposed on audit data. An audit trail requires mechanisms for a complete reconstruction of every action taken against the database [BJOR75, BONY8 ...
... mechanisms to achieve these objectives. In addition to the actual recording of all events that take place in the database, a logical structure needs to be imposed on audit data. An audit trail requires mechanisms for a complete reconstruction of every action taken against the database [BJOR75, BONY8 ...
Database System Architectures
... Implementation Issues for Distributed Databases Atomicity needed even for transactions that update data at multiple sites The two-phase commit protocol (2PC) is used to ensure atomicity Basic idea: each site executes transaction until just before commit, and the leaves final decision to a coordinat ...
... Implementation Issues for Distributed Databases Atomicity needed even for transactions that update data at multiple sites The two-phase commit protocol (2PC) is used to ensure atomicity Basic idea: each site executes transaction until just before commit, and the leaves final decision to a coordinat ...
cs440outline - Computer Science Home
... and the concept of data independence. b) Describe the theories including functional dependencies and normalization and their consequences in database design. c) Analyze major data models including the entity-relationship, the relational, and objectoriented models. d) Explain top-down database planni ...
... and the concept of data independence. b) Describe the theories including functional dependencies and normalization and their consequences in database design. c) Analyze major data models including the entity-relationship, the relational, and objectoriented models. d) Explain top-down database planni ...
part 1 - Faculty
... Commit protocols are used to ensure atomicity across sites a transaction which executes at multiple sites must either be committed at all the sites, or aborted at all the sites. not acceptable to have a transaction committed at one site and aborted at another ...
... Commit protocols are used to ensure atomicity across sites a transaction which executes at multiple sites must either be committed at all the sites, or aborted at all the sites. not acceptable to have a transaction committed at one site and aborted at another ...
Distributed Database Systems
... funcuonal again) to see if any transactions were in progress at the time of the failure. If there was such a transaction, all operations in that transacUon that were executed prior to the crash are "undone", so that the database is returned to the (consistent) state it was in at the time the transac ...
... funcuonal again) to see if any transactions were in progress at the time of the failure. If there was such a transaction, all operations in that transacUon that were executed prior to the crash are "undone", so that the database is returned to the (consistent) state it was in at the time the transac ...
Slide 1
... – Transaction log backup is created on the primary server – File is copied to the secondary server • Log is restored on the secondary server – NORECOVERY (database remains offline) – STANDBY (database is read-only) ...
... – Transaction log backup is created on the primary server – File is copied to the secondary server • Log is restored on the secondary server – NORECOVERY (database remains offline) – STANDBY (database is read-only) ...
download
... Media failures that affect datafiles can be divided into two categories: read errors and write errors. In a read error, Oracle discovers it cannot read a datafile and an operating system error is returned to the application, along with an Oracle error indicating that the file cannot be found, cannot ...
... Media failures that affect datafiles can be divided into two categories: read errors and write errors. In a read error, Oracle discovers it cannot read a datafile and an operating system error is returned to the application, along with an Oracle error indicating that the file cannot be found, cannot ...
Chapter 19: Distributed Databases
... A network is said to be partitioned when it has been split into two or more subsystems that lack any connection between them – Note: a subsystem may consist of a single node ...
... A network is said to be partitioned when it has been split into two or more subsystems that lack any connection between them – Note: a subsystem may consist of a single node ...
Database - UTRGV Faculty Web
... The GUI wizard (similar to Access) Choose the name of the fields Set the type of the fields Set possible constraints (“allow nulls”) Define the primary key Define possible foreign keys ...
... The GUI wizard (similar to Access) Choose the name of the fields Set the type of the fields Set possible constraints (“allow nulls”) Define the primary key Define possible foreign keys ...
Database Systems
... • Distributed databases make it possible for transaction to access data at several sites • Final COMMIT is issued after all sites have committed their parts of transaction • Requires that each DP’s transaction log entry be written before database fragment updated • DO-UNDO-REDO protocol with write-a ...
... • Distributed databases make it possible for transaction to access data at several sites • Final COMMIT is issued after all sites have committed their parts of transaction • Requires that each DP’s transaction log entry be written before database fragment updated • DO-UNDO-REDO protocol with write-a ...
Here - NYU Computer Science Department
... • The payroll department can see salaries but cannot see diseases. • The health department can see diseases but cannot see salaries. Users may prefer to look at different aspects of the information. ...
... • The payroll department can see salaries but cannot see diseases. • The health department can see diseases but cannot see salaries. Users may prefer to look at different aspects of the information. ...
Database
... • data warehouse, OLAP - analysis, decision making • real-time, active databases - industrial processes • deductive databases - combination of inference and ...
... • data warehouse, OLAP - analysis, decision making • real-time, active databases - industrial processes • deductive databases - combination of inference and ...
Chapter 14: Concurrency Control
... The value of Q that Ti is producing was needed previously, and the system assumed that that value would never be produced. Hence, the write operation is rejected, and Ti is rolled back. ...
... The value of Q that Ti is producing was needed previously, and the system assumed that that value would never be produced. Hence, the write operation is rejected, and Ti is rolled back. ...