Transaction Management Overview
... (except with CONNECT) and terminated with either a COMMIT or a ...
... (except with CONNECT) and terminated with either a COMMIT or a ...
Concurrency Control Chapter Handbook of Database Technology
... that an error occurred in the concurrent execution of H1', and that this error was caused by Interference in concurrent access to the data: It occurs because P2 remembers the value of A as 100, even after P1 had already added 30 to make it 130, P2 then performs an update that wipes out P1's effect. ...
... that an error occurred in the concurrent execution of H1', and that this error was caused by Interference in concurrent access to the data: It occurs because P2 remembers the value of A as 100, even after P1 had already added 30 to make it 130, P2 then performs an update that wipes out P1's effect. ...
Transactions
... Let S and S´ be two schedules with the same set of transactions. S and S´ are view equivalent if the following three conditions are met: 1. For each data item Q, if transaction Ti reads the initial value of Q in schedule S, then transaction Ti must, in schedule S´, also read the initial value of Q. ...
... Let S and S´ be two schedules with the same set of transactions. S and S´ are view equivalent if the following three conditions are met: 1. For each data item Q, if transaction Ti reads the initial value of Q in schedule S, then transaction Ti must, in schedule S´, also read the initial value of Q. ...
CSc-340 10a
... Thus serial execution of a set of transactions preserves database consistency. A (possibly concurrent) schedule is serializable if it is equivalent to a serial schedule. Different forms of schedule equivalence give rise to the notions of: 1. conflict serializability 2. view serializability ...
... Thus serial execution of a set of transactions preserves database consistency. A (possibly concurrent) schedule is serializable if it is equivalent to a serial schedule. Different forms of schedule equivalence give rise to the notions of: 1. conflict serializability 2. view serializability ...
26-Mar - University of Pennsylvania
... Means of Handling Failures There are many (especially, financial) applications where we want to create atomic operations that either commit or roll back This is one of the most basic services provided by database management systems, but we want to do it in a broader sense Part of “ACID” semant ...
... Means of Handling Failures There are many (especially, financial) applications where we want to create atomic operations that either commit or roll back This is one of the most basic services provided by database management systems, but we want to do it in a broader sense Part of “ACID” semant ...
Concurrent Control
... concurrently, the nonserial schedule is called serializable if it produces the same results as a serial schedule. ...
... concurrently, the nonserial schedule is called serializable if it produces the same results as a serial schedule. ...
Chapter 15
... transactions. S and S´ are view equivalent if: 1. For each data item Q, if transaction Ti reads the initial value of Q in schedule S, then transaction Ti must, in schedule S´, also read the initial value of Q. 2. For each data item Q if transaction Ti executes read(Q) in schedule S, and that value w ...
... transactions. S and S´ are view equivalent if: 1. For each data item Q, if transaction Ti reads the initial value of Q in schedule S, then transaction Ti must, in schedule S´, also read the initial value of Q. 2. For each data item Q if transaction Ti executes read(Q) in schedule S, and that value w ...
transaction
... different tradeoffs between the amount of concurrency they allow and the amount of overhead that they incur. • Serializability Tests help us understand why a concurrency control protocol is correct. ...
... different tradeoffs between the amount of concurrency they allow and the amount of overhead that they incur. • Serializability Tests help us understand why a concurrency control protocol is correct. ...
Document
... • We can flip ri(X); wj(Y), as long as X≠Y • That is, ri(X); wj (X) wj(X); ri (X) – In the RHS, Ti reads the value of X written by Tj, whereas it is not so in the LHS. ...
... • We can flip ri(X); wj(Y), as long as X≠Y • That is, ri(X); wj (X) wj(X); ri (X) – In the RHS, Ti reads the value of X written by Tj, whereas it is not so in the LHS. ...
ch15
... transaction may not be serializable – it may find some records inserted by a transaction but not find others. Read committed — only committed records can be read, but ...
... transaction may not be serializable – it may find some records inserted by a transaction but not find others. Read committed — only committed records can be read, but ...
Overview of Transaction Processing Systems
... devices to protect against media failure • Architecture of mass storage devices affects type of media failures that can be tolerated • Related to Availability: extent to which a (possibly distributed) system can provide service despite failure • Non-stop DBMS (mirrored disks) • Recovery based DBMS ( ...
... devices to protect against media failure • Architecture of mass storage devices affects type of media failures that can be tolerated • Related to Availability: extent to which a (possibly distributed) system can provide service despite failure • Non-stop DBMS (mirrored disks) • Recovery based DBMS ( ...
A Closer Look
... devices to protect against media failure • Architecture of mass storage devices affects type of media failures that can be tolerated • Related to Availability: extent to which a (possibly distributed) system can provide service despite failure • Non-stop DBMS (mirrored disks) • Recovery based DBMS ( ...
... devices to protect against media failure • Architecture of mass storage devices affects type of media failures that can be tolerated • Related to Availability: extent to which a (possibly distributed) system can provide service despite failure • Non-stop DBMS (mirrored disks) • Recovery based DBMS ( ...
A Closer Look
... devices to protect against media failure • Architecture of mass storage devices affects type of media failures that can be tolerated • Related to Availability: extent to which a (possibly distributed) system can provide service despite failure • Non-stop DBMS (mirrored disks) • Recovery based DBMS ( ...
... devices to protect against media failure • Architecture of mass storage devices affects type of media failures that can be tolerated • Related to Availability: extent to which a (possibly distributed) system can provide service despite failure • Non-stop DBMS (mirrored disks) • Recovery based DBMS ( ...
On the complexity of nested relational operations
... e.g. only the employees named Smith, or the join of the employee subrelation with a children relation, and the likes. Therefore, not all projections can be linear. This is the reason why we use the term single pass rather than the classical single table operation. One possible restriction is that on ...
... e.g. only the employees named Smith, or the join of the employee subrelation with a children relation, and the likes. Therefore, not all projections can be linear. This is the reason why we use the term single pass rather than the classical single table operation. One possible restriction is that on ...
National Academy for Software Development
... • Lock and unlock requests are handled by the lock manager, stored in the “lock table” • Lock table entries store: • Number of transactions currently holding a lock • Type of lock held (shared or exclusive) • Pointer to queue of lock requests ...
... • Lock and unlock requests are handled by the lock manager, stored in the “lock table” • Lock table entries store: • Number of transactions currently holding a lock • Type of lock held (shared or exclusive) • Pointer to queue of lock requests ...
11 Scalability Concepts Every Architect Should Understand
... hands-on coding. Bill is a Windows Azure MVP, an active speaker, blogger (blog.codingoutloud.com), and tweeter (@codingoutloud) on technology matters and soft skills for technologists, a member of Boston West Toastmasters, and has a day job as a .NET-focused ...
... hands-on coding. Bill is a Windows Azure MVP, an active speaker, blogger (blog.codingoutloud.com), and tweeter (@codingoutloud) on technology matters and soft skills for technologists, a member of Boston West Toastmasters, and has a day job as a .NET-focused ...
transaction
... Active – the initial state; the transaction stays in this state while it is executing Partially committed – after the final statement has been executed. Failed -- after the discovery that normal execution ...
... Active – the initial state; the transaction stays in this state while it is executing Partially committed – after the final statement has been executed. Failed -- after the discovery that normal execution ...
Transactions Transactions Transaction Concept Example of Fund
... In case transaction fails, old consistent copy pointed to by db_pointer can be used, and the shadow copy can be deleted. ...
... In case transaction fails, old consistent copy pointed to by db_pointer can be used, and the shadow copy can be deleted. ...
Slides
... • In production environments, it is unlikely that we can limit our system to just one user at a time. – Consequently, it is possible for multiple queries or transactions to be submitted at approximately the same time. • If all of the queries were very small (i.e., in terms of time), we could probabl ...
... • In production environments, it is unlikely that we can limit our system to just one user at a time. – Consequently, it is possible for multiple queries or transactions to be submitted at approximately the same time. • If all of the queries were very small (i.e., in terms of time), we could probabl ...
+ Database Consistency
... of mass storage devices affects type of media failures that can be tolerated ...
... of mass storage devices affects type of media failures that can be tolerated ...
4_sql_recovery_1
... A useful way to view the read committed and serializable isolation levels in Oracle is to consider the following scenario: Assume you have a collection of database tables (or any set of data), a particular sequence of reads of rows in those tables, and the set of transactions committed at any partic ...
... A useful way to view the read committed and serializable isolation levels in Oracle is to consider the following scenario: Assume you have a collection of database tables (or any set of data), a particular sequence of reads of rows in those tables, and the set of transactions committed at any partic ...
transaction
... Database consists of objects (X, Y, Z), each of them is an integer Transactions are labeled T1, T2 etc. Each transaction has a set of local variables (not accessible by other transactions) in main memory. ...
... Database consists of objects (X, Y, Z), each of them is an integer Transactions are labeled T1, T2 etc. Each transaction has a set of local variables (not accessible by other transactions) in main memory. ...