ITSS CH10

Requires that all operations (SQL requests) to be completed; if not the transaction is aborted

Propert that requires all parts of a transaction to be treated as a single, logical unit of work in which all operations must completed to produce a consistent database

Lock that has only two states: locked (1) and unlocked (0)

Shared, reserved memory area that stores the most recently accessed data blocks in RAM.

Transaction management, an operation in which the database management system writes all of its updated buffers to disk

DBMS feature that coordinates the simultaneous execution of transactions in a multiprocessing database system

Database condition in which all data integrity constraints are satisfied.

Database state in which all data integrity constraints are satisfied

Type of lock that restricts database access to the owner of the lock and allows only one user at a time to access the database.

Process of restoring a database to a previous consistent state

The equivalent of a single SQL statement in application program or transaction

Condition in which two or more transaction wait indefinitely for the other to release the lock on previously locked data

is another name for deadlock

Transaction management, a condition in which transaction operations do not immediately update a physical database

is another name for deffered update

Permanent storage, the equivalent of a disk block, which can be describes as a directly addressable selction of a disk.

Transaction property that indicated the permanence of a database's consistent state.

Lock that is reserved by a transaction. Lock is issued when a transaction requests permission to update a data item.

Lock that allows concurrent transactions to access the same roww as long as they require the use of different fields within that row

Database update that is performed immediately during a transaction's execution, even before the transaction reaches its commit point

Concurrency control problem that arises when a transaction-calculating summary functions over set of data while other transaction are updating the data

Property of a database transaction in which a data item used by one transaction is not available to other transaction until the first one ends.

Device that gurantees unique use of a data item in a particular transaction opertaion.

The Level of lock use. Locking can take place at the following levels: database, table, page, row, and field.

A DBMS component that is responsible for assigning and releasing locks

Concurrency control problem in which data updates are lost during the concurrent execution of transactions.

Quality that ensures that timestamp values always increase.

A condition in which only one transaction at a time can own an exclusive lock on the same object

Occurs when a transaction reads the same row twice but gets different data each time

Transaction management, a concurrency control technique based on the assumption that most database operations do not conflict

In permanent storage, the equivalent of a disk block, which can be described as a directly addressable section of a disk.

The database managment system locks an entire dispage, ore section of a disk

the use of locks based on the assumption that conflict between transaction is likely

In transaction management, when a transaction executes a query at time t1, then runs the same query at time t2, yielding additional rows that satisfy the query.

isolation level uses shared locks for read operations on each statement. This default isolation level prevents dirty reads, but allows non-repeatable and phantom reads.

An ANSI SQL transaction isolation level that allows transactions to read uncommitted data from other transactions, and which allows nonrepeatable reads and phantom reads. The least restrictive level defined by ANSI SQL.

Multiple copies of the transaction log kept by database management systems to ensure that the physical failure of a disk will not impair the DBMS's ability to recover data

An ANSI SQL transaction isolation level that uses shared locks to ensure that other transactions do not update a row after the original query updates it. However, phantom reads are allowed.

Less restrictive database lock in which the DMBS allows concurrent transactions to access different rows of the same table, even when the rows are on the same page

DBMS component that establishes the order in which concurrent transaction operations are executed.

A schedule of operations in which the interleaved executation of the transaction yields the same result as if they were executed in a serial order

Property in which the selected order of transaction operations creates the same final database state that would have been produced if the transaction has been execcuted

Lock that is issued when a transaction requests permission to read data from a database and no exclusive locks are held on the data by another transaction

Locking scheme that allows only one transaction at a time to access a table

Technique used in scheduling concurrent transactions that assigns a global unique timestamp to each transaction

Sequence of database requests that accesses the database.

Feature used by the DBMS to keep track of all transaction operations that update the database

Set of rules that governs how transaction acquire and relinquish locks. Two phase locking protocol is divided into two phases: growing and shrinking phase

When you are trying to achieve concurrency control, uncommitted data cause problems with data integrity and consistency.

Property of timestamping that ensures no equal timestamp values can exist

Concurrency control scheme in which an older transaction must wait for the younger transaction to complete and release the locks before requesting the locks itself

Concurrency control scheme in which an older transaction can request the lock, preempt the younger transaction, and reschedule it.

Process that ensures transaction logs are written to permanent storage before any database data are actually updated.

Process that ensures a database is immediately updated by operations during the transaction's execution, even before the transaction reaches its commit point