Distributed Deadlock Detection
... Newly elected coordinator will send STATEREQ message to all participants involved in election to determine how best to continue. If some participant has aborted, then abort. If some participant has committed, then commit. If all participants are uncertain, then abort. If some participant is in PRE-C ...
... Newly elected coordinator will send STATEREQ message to all participants involved in election to determine how best to continue. If some participant has aborted, then abort. If some participant has committed, then commit. If all participants are uncertain, then abort. If some participant is in PRE-C ...
Database System Architectures
... To avoid overhead of interprocess communication for lock request/grant, each database process operates directly on the lock table data structure (Section 16.1.4) instead of sending requests to lock manager process ...
... To avoid overhead of interprocess communication for lock request/grant, each database process operates directly on the lock table data structure (Section 16.1.4) instead of sending requests to lock manager process ...
Database management system Document Notes
... A database is an integrated collection of logically related records or files consolidated into a common pool that provides data for one or more multiple uses. You can think of a database as an electronic filing system. A Database Management System (DBMS) Software that organizes the storage of data. ...
... A database is an integrated collection of logically related records or files consolidated into a common pool that provides data for one or more multiple uses. You can think of a database as an electronic filing system. A Database Management System (DBMS) Software that organizes the storage of data. ...
20InternalDBAspects
... If there are more than about 64000 objects, the bitstrings are divided in so called chunks Abbreviations are used for all 1 or all 0 If a bitmap index is defined for a class automatically an extent bitmap index is maintained: It stores 1 if the Id exists, and 0 if not. ...
... If there are more than about 64000 objects, the bitstrings are divided in so called chunks Abbreviations are used for all 1 or all 0 If a bitmap index is defined for a class automatically an extent bitmap index is maintained: It stores 1 if the Id exists, and 0 if not. ...
Materialy/32/Lectures Oracle
... start and stop the database structuring the database definition of tablespaces file allocation for tablespaces distribution of database files to disks definition of rollback segments (size, count, place, ...) development and implementation of strategies for backup / recovery of the database ...
... start and stop the database structuring the database definition of tablespaces file allocation for tablespaces distribution of database files to disks definition of rollback segments (size, count, place, ...) development and implementation of strategies for backup / recovery of the database ...
Course Name : Database Management Systems
... The actions are listed in the order they are scheduled, and prefixed with the transaction name.If a commit or abort is not shown, the schedule is incomplete; assume that abort/commit must follow all the listed actions. 1. T1:R(X), T2:R(X), T1:W(X), T2:W(X) 2. T1:W(X), T2:R(Y), T1:R(Y), T2:R(X) 3. T1 ...
... The actions are listed in the order they are scheduled, and prefixed with the transaction name.If a commit or abort is not shown, the schedule is incomplete; assume that abort/commit must follow all the listed actions. 1. T1:R(X), T2:R(X), T1:W(X), T2:W(X) 2. T1:W(X), T2:R(Y), T1:R(Y), T2:R(X) 3. T1 ...
ppt - Spatial Database Group
... Consume significant resources Significant cost component Transaction design important ...
... Consume significant resources Significant cost component Transaction design important ...
paper - VLDB Endowment
... level during the execution of that transaction. When a readonly transaction Ti with the freshness requirement of T S wants to access some objects, it first has to acquire freshness locks on these objects. The procedure for acquiring freshness locks is performed in two steps: 1. Ti asks for a freshne ...
... level during the execution of that transaction. When a readonly transaction Ti with the freshness requirement of T S wants to access some objects, it first has to acquire freshness locks on these objects. The procedure for acquiring freshness locks is performed in two steps: 1. Ti asks for a freshne ...
Introduction to Oracle - University of Windsor
... changed block. Since Oracle uses write-ahead logging, DBWR does not need to write blocks when a transaction commits. In the most common case, DBWR writes only when more data needs to be read into the system global area and too few database buffers are free. The least recently used data is written to ...
... changed block. Since Oracle uses write-ahead logging, DBWR does not need to write blocks when a transaction commits. In the most common case, DBWR writes only when more data needs to be read into the system global area and too few database buffers are free. The least recently used data is written to ...
Scalar Aggregation in FD-Inconsistent Databases
... Definition 9. Given a class of databases D, a class of queries L and a class of integrity constraints, the data complexity of computing consistent query answers is defined to be the complexity of (deciding the membership of ) the sets DF,φ = {(D, t̄) : D |=F φ[t̄]} for a fixed φ ∈ L and a fixed fini ...
... Definition 9. Given a class of databases D, a class of queries L and a class of integrity constraints, the data complexity of computing consistent query answers is defined to be the complexity of (deciding the membership of ) the sets DF,φ = {(D, t̄) : D |=F φ[t̄]} for a fixed φ ∈ L and a fixed fini ...
6231B_07
... Use the RESTORE DATABASE statement to restore a full database backup of the master database ...
... Use the RESTORE DATABASE statement to restore a full database backup of the master database ...
Data concurrency
... transaction are locked for the duration of that transaction. With this isolation level, any SELECT statement that is issued more than once within the same transaction will always yield the same results; lost updates, dirty reads, nonrepeatable reads, and phantoms cannot occur. Transactions using the ...
... transaction are locked for the duration of that transaction. With this isolation level, any SELECT statement that is issued more than once within the same transaction will always yield the same results; lost updates, dirty reads, nonrepeatable reads, and phantoms cannot occur. Transactions using the ...
Database Recovery
... The minimum unit of collections of operations that form a single logical step of work is called a transaction. Since a transaction is indivisible, it either executes in its entirety or not at all. Transaction and Program ...
... The minimum unit of collections of operations that form a single logical step of work is called a transaction. Since a transaction is indivisible, it either executes in its entirety or not at all. Transaction and Program ...
Database Management System (DBMS) an Introduction
... • Understand why databases are important to modern organizations • Understand how databases work • Understand how organizations can maximize their strategic potential with databases ...
... • Understand why databases are important to modern organizations • Understand how databases work • Understand how organizations can maximize their strategic potential with databases ...
Optimistic Concurrency Control in a Distributed NameNode
... the data rows to in-memory objects used by the name system. Namespace Concurrency Control In the first version of Hop-HDFS [6] (also named as KTHFS), the main task is to migrate the metadata from memory to MySQL Cluster. Therefore, it still depends on the system-level lock in HDFS NameNode (fsLock i ...
... the data rows to in-memory objects used by the name system. Namespace Concurrency Control In the first version of Hop-HDFS [6] (also named as KTHFS), the main task is to migrate the metadata from memory to MySQL Cluster. Therefore, it still depends on the system-level lock in HDFS NameNode (fsLock i ...
Chapter 15 Duplicating Databases and Transporting Data
... auxiliary (destination) instance. You must start the auxiliary instance with the nomount option. You can’t use a standby database as the target database. You’ll need the password file for the auxiliary instance only if you’re using the RMAN client on a different host than the auxiliary host or ...
... auxiliary (destination) instance. You must start the auxiliary instance with the nomount option. You can’t use a standby database as the target database. You’ll need the password file for the auxiliary instance only if you’re using the RMAN client on a different host than the auxiliary host or ...
Introduction to Transaction Processing Concepts and Theory
... • Interleaving of operations occurs in an operating system through some scheduler • Difficult to determine before hand how the operations in a schedule will be interleaved. ...
... • Interleaving of operations occurs in an operating system through some scheduler • Difficult to determine before hand how the operations in a schedule will be interleaved. ...
ppt
... Improve performance by storing a denormalized relation E.g., store join of account and depositor; branch-name and balance information is repeated for each holder of an account, but join need not be computed repeatedly. – Price paid: more space and more work for programmer to keep relation consiste ...
... Improve performance by storing a denormalized relation E.g., store join of account and depositor; branch-name and balance information is repeated for each holder of an account, but join need not be computed repeatedly. – Price paid: more space and more work for programmer to keep relation consiste ...
Structured Query Language
... Create database indexes Explain what a database view is and when it should be used Create a database view Database security Create new users and roles/groups Grant and revoke priveleges for users and groups on database objects Drop user and roles/groups Writing SQL scripts Write and sa ...
... Create database indexes Explain what a database view is and when it should be used Create a database view Database security Create new users and roles/groups Grant and revoke priveleges for users and groups on database objects Drop user and roles/groups Writing SQL scripts Write and sa ...
Database Systems
... data to be used by the transaction; functional characteristics of the transaction; output of the transaction; importance to the users; expected rate of usage. Three main types of transactions: retrieval, update, and mixed. ...
... data to be used by the transaction; functional characteristics of the transaction; output of the transaction; importance to the users; expected rate of usage. Three main types of transactions: retrieval, update, and mixed. ...
Cooperative Query Processing via Knowledge Abstraction and
... One of the best applications of the cooperative query processing approach is probably the responsive online sales support in Web sites. Without intelligent help in conducting searches for a specific item on a Web site, customers are likely to be dissatisfied with their query’s answer set. Unless use ...
... One of the best applications of the cooperative query processing approach is probably the responsive online sales support in Web sites. Without intelligent help in conducting searches for a specific item on a Web site, customers are likely to be dissatisfied with their query’s answer set. Unless use ...