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2024년 12월 13일 (금)

• 01:402024년 12월 13일 (금) 01:40 차이 역사 +3,490‎ 새글 Multiversion Concurrency Control ‎ Created page with "'''Multiversion Concurrency Control (MVCC)''' is a concurrency control method used in database systems that allows multiple versions of a data item to exist simultaneously. It ensures consistent reads without locking and provides high concurrency by maintaining transaction isolation. ==Key Concepts== *'''Data Versioning:''' MVCC creates a new version of a data item for every write operation, enabling transactions to access consistent snapshots. *'''Timestamps:''' Each tr..." 최신 태그: 시각 편집
• 01:392024년 12월 13일 (금) 01:39 차이 역사 +3,700‎ 새글 Timestamp-Based Protocol ‎ Created page with "'''Timestamp-Based Protocol''' is a concurrency control mechanism in database systems that uses timestamps to order transactions, ensuring serializability. Each transaction is assigned a unique timestamp when it begins, and the protocol uses these timestamps to determine the execution order of conflicting operations. ==Key Concepts== *'''Timestamp:''' A unique identifier (usually based on the system clock or a counter) assigned to each transaction when it starts. *'''Rea..." 최신 태그: 시각 편집
• 01:352024년 12월 13일 (금) 01:35 차이 역사 +3,804‎ 새글 Lock-Based Protocol ‎ Created page with "'''Lock-Based Protocol''' is a concurrency control mechanism in database systems that ensures transaction isolation by managing access to data items through locks. Locks prevent simultaneous transactions from interfering with each other, ensuring data consistency and serializability. ==Key Concepts== *'''Lock:''' A mechanism that restricts access to a data item for concurrent transactions. *'''Lock Modes:''' **'''Shared Lock (S):''' Allows multiple transactions to read a..." 최신 태그: 시각 편집
• 01:332024년 12월 13일 (금) 01:33 차이 역사 +3,740‎ 새글 Two-Phase Locking ‎ Created page with "'''Two-Phase Locking (2PL)''' is a concurrency control protocol used in database systems to ensure serializability of transactions. It operates in two distinct phases where locks are acquired and released in a specific order, preventing conflicts between concurrent transactions. ==Key Concepts== *'''Locking Protocol:''' Transactions acquire locks on data items before accessing them and release locks when no longer needed. *'''Serializability:''' 2PL guarantees that the r..." 최신 태그: 시각 편집
• 01:312024년 12월 13일 (금) 01:31 차이 역사 +3,880‎ 새글 Concurrency Control ‎ Created page with "'''Concurrency Control''' is a mechanism in database management systems (DBMS) that ensures correct and consistent transaction execution in a multi-user environment. It prevents issues such as data inconsistencies and anomalies by managing simultaneous access to the database. ==Key Concepts== *'''Transaction:''' A sequence of database operations that are executed as a single logical unit of work. *'''Isolation:''' Ensures that each transaction is executed independently w..." 최신 태그: 시각 편집
• 01:282024년 12월 13일 (금) 01:28 차이 역사 +472‎ Isolation Level (Database) ‎편집 요약 없음 최신
• 01:282024년 12월 13일 (금) 01:28 차이 역사 +3,623‎ 새글 Isolation Level (Database) ‎ Created page with "'''Isolation Level''' is a property in database transaction management that defines the extent to which transactions are isolated from each other. It determines how and when changes made by one transaction are visible to other concurrent transactions, affecting the trade-off between consistency and concurrency. ==Key Concepts== *'''Transaction Isolation:''' Ensures that concurrent transactions do not interfere with each other inappropriately. *'''Anomalies:''' Lower isol..." 태그: 시각 편집
• 01:262024년 12월 13일 (금) 01:26 차이 역사 +22‎ Non-Repeatable Read ‎편집 요약 없음 최신 태그: 시각 편집
• 01:262024년 12월 13일 (금) 01:26 차이 역사 +3,763‎ 새글 Non-Repeatable Read ‎ Created page with "'''Non-Repeatable Read''' is a concurrency problem in database systems that occurs when a transaction reads the same data twice and gets different results due to modifications made by another transaction in the meantime. This inconsistency arises when isolation levels do not guarantee stability for repeated reads of the same data. ==Key Concepts== *'''Unstable Reads:''' The data read by a transaction changes during its execution because another transaction modifies it. *..." 태그: 시각 편집
• 01:262024년 12월 13일 (금) 01:26 차이 역사 +3,626‎ 새글 Dirty Read (Database) ‎ Created page with "'''Dirty Read''' is a concurrency problem in database systems that occurs when a transaction reads uncommitted changes made by another transaction. This can lead to inconsistent or incorrect data being used in the reading transaction, especially if the changes are later rolled back. ==Key Concepts== *'''Uncommitted Data:''' Data modified by a transaction that has not yet been committed to the database. *'''Concurrency Issue:''' Dirty reads are a type of Database Anomal..." 최신 태그: 시각 편집
• 01:232024년 12월 13일 (금) 01:23 차이 역사 +2,874‎ 새글 Precedence Graph ‎ Created page with "'''Precedence Graph''', also known as a '''Serializability Graph''', is a directed graph used in database systems to determine the serializability of a transaction schedule. The graph represents the order of operations across transactions and helps identify potential conflicts that could prevent a schedule from being equivalent to a serial schedule. ==Key Concepts== *'''Nodes:''' Represent individual transactions in the schedule. *'''Edges:''' Indicate a precedence (or d..." 최신 태그: 시각 편집