CSE 4202: Database Systems Design & Information Management Systems 2 - Session 02

Vocabulary practice flashcards covering database administration, security, transaction management, and recovery based on the CSE 4202 lecture.

Data Administration

The management of the data resource, which includes database planning, development, and maintenance of standards, policies and procedures, and conceptual and logical database design.

Database Administration

The management of the physical realization of a database system, which includes physical database design and implementation, setting security and integrity controls, monitoring system performance, and reorganizing the database, as necessary.

Database Security

The mechanisms that protect the database against unauthorized access, either intentional or accidental threats.

Threat

Any situation or event, whether intentional or accidental, that may adversely affect a system and consequently the organization.

Authorization

The granting of a right or privilege that enables a subject to have legitimate access to a system or a system’s object.

Authentication

A mechanism that determines whether a user is who he or she claims to be.

Discretionary Access Control (DAC)

A method to manage privileges via SQL GRANT and REVOKE, though a weakness is that unauthorized users may trick authorized users into disclosing sensitive data.

Mandatory Access Control (MAC)

Security based on system-wide policies where each database object is assigned a security class and each user is assigned a clearance.

View

A virtual relation that does not actually exist in the database, but is produced upon request by a particular user to hide parts of the database.

Backup

The process of periodically copying the database and log file (and possibly programs) to offline storage media.

Journaling

The process of keeping and maintaining a log file (or journal) of all changes made to the database to enable effective recovery.

Encryption

The encoding of data by a special algorithm that renders the data unreadable by any program without the decryption key.

RAID

A large disk array comprising an arrangement of several independent disks organized to improve reliability and increase performance.

Concurrency Control

Functions that prevent simultaneous database accesses from interfering with one another.

Recovery

The process of restoring the database to a correct state following a failure.

Transaction

A logical unit of work on the database that carries out actions to read or update contents, moving the database from one consistent state to another.

ACID Properties

The four key properties of a transaction: Atomicity, Consistency, Isolation, and Durability.

Lost Update Problem

A concurrency problem where a successfully completed update operation by one user is overridden by another user.

Uncommitted Dependency Problem

Occurs when one transaction is allowed to see the intermediate results of another transaction before it has committed.

Inconsistent Analysis Problem

Occurs when a transaction reads several values but a second transaction updates some of them during the execution of the first.

Serializability

A means of identifying executions of transactions that are guaranteed to ensure consistency by producing the same result as some serial execution.

Schedule

A sequence of operations by a set of concurrent transactions that preserves the order of operations in each individual transaction.

Serial Schedule

A schedule where the operations of each transaction are executed consecutively without interleaved operations from other transactions.

Recoverable Schedule

A schedule in which for each pair of transactions $T1$ and $T2$, if $T2$ reads a data item previously written by $T1$, then the commit of $T1$ precedes the commit of $T2$.

Shared Lock

A lock that allows a transaction to read a data item but prevents it from updating it.

Exclusive Lock

A lock that allows a transaction to both read and update a data item.

Two-phase locking (2PL)

A protocol where all locking operations in a transaction must precede the first unlock operation.

Latch

A type of lock held for a much shorter duration than a normal lock.

Deadlock

An impasse resulting when two or more transactions are each waiting for locks held by the other to be released.

Timestamp

A unique identifier created by the DBMS that indicates the relative starting time of a transaction.

Steal Policy

A buffer management policy that allows the manager to write a buffer to disk before a transaction commits.

Force Policy

A buffer management policy ensuring that all pages updated by a transaction are immediately written to disk when the transaction commits.

Checkpoint

The point of synchronization between the database and the transaction log file where all buffers are force-written to secondary storage.

Deferred Update

A recovery protocol where updates are not written to the database until after a transaction has reached its commit point.

Immediate Update

A recovery protocol where updates are applied to the database as they occur without waiting for the commit point.

Shadow Paging

A recovery technique that maintains two page tables: a current page table and a shadow page table.