Shared lock (s lock ):If transaction t adds a shared lock to data a, other transactions can only add a shared lock to data a, but cannot apply an exclusive lock until all shared locks are released. Transactions authorized to share locks can only read data and cannot modify data.Exclusive lock (x lock ):If transaction t adds an exclusive lock to data a, other transactions cannot add any type of lock to aunti
Document directory
Getting started
Working with CVS in Eclipse
Sending files to the server
Retrieving a former version of a file
Don't forget to UPDATE!
Importing an existing project
Setting up CVS in Adobe Flex
ThisTutorial will show you how to get started using CVS (ConcurrentVersions System) and how you use it. CV
For forum discussion, please see: http://community.csdn.net/Expert/topic/3492/3492097.xml?temp=.1520502
The idea of CVS is the most powerful and best CVS client I have ever seen, and the integration of the project is almost seamless. If a team uses idea uniformly, it will greatly reduce the learning burden of team members in the CVS tool alone. Idea's
Optimistic locks and pessimistic locks, optimistic locks pessimistic locks
Locking)
This concept has been touched upon when we learned multithreading. In fact, the lock here and the concurrent lock processing in multithreading are a truth. They all violently classify resources as their own. Here, we use
It is difficult to use pserver-based Remote Authentication in CVS. You need to define the server and user group, user name, and password,
Common login formats are as follows:CVS-D: pserver: cvs_user_name@cvs.server.address:/path/to/cvsroot LoginExample:CVS-D: pserver: cvs@samba.org:/cvsroot Login
It is not safe, so it is generally used as an anonymous read-only CVS
How the CVS client is used in eclipseBasic situation: In Eclipse has been self-contained CVS client plug-in, directly can link to the CVS server, but need to pay attention to the link information, must be with the previous on the CVS server, set the information consistent;How do I link a
When you build your Java Automation Test integration environment, whatever you do, you will choose a source control tool, such as SVN,CVS,VSS, etc. but if you use the Eclipse tool, it is recommended that you use the CVS Source Control tool because it comes with the CVS client plugin itself. can be used directly (for specific usage, refer to: Java Automation Test
Update lost: New changes to overwrite first, the development of three ways to solve
1, raise the transaction level to the highest level transaction_serializable
Both sides of the operation should raise the level; The query uses the shared lock; updates use the update lock; one query, one update, the shared lock and the update lock conflict; When both sides update the lock and a deadlock occurs, the program automatically rolls back one side of the operation to avoid the loss of the update
2, p
CVS User ManualKeywords: CVs Cvsweb cvstrac wincvs cvsroot
Summary:
CVS is a C/S system. Multiple developers use a central version control system to record file versions to ensure file synchronization. The working mode is as follows:
CVS server (file version Library)
/|/
(Same step for Version)
/|/
Developer 1 develope
Page Level: Engine BDB.Table-level: Engine MyISAM, which is interpreted as locking the entire table and reading at the same time.Row-level: Engine INNODB, locking a single row of records
At the table level, the entire table is locked directly. During the lock period, other processes cannot perform write operations on the table. If you are writing a lock, other processes are not allowed to read it.Row-level, which only locks specified records, so that
In computer science, a lock is a synchronization mechanism used to forcibly restrict access to resources in the execution of multiple threads, which is used to guarantee the satisfaction of mutex requirements in concurrency control.
In the DBMS, database locks can be divided into row-level locks (InnoDB engines), table-level locks (MyISAM engines), and page-leve
MySQL row-level lock, table-level lock, page-level lock details page-level: engine BDB.
Table-level: engine MyISAM, which is interpreted as locking the entire table and reading at the same time.
Row-level: engine INNODB, locking a single row of records
At the table level, the entire table is locked directly. during the lock period, other processes cannot perform write operations on the table. If you are writing a lock, other processes are not allowed to read it.Row-level, which only
Page level: Engine BDB.Table level: Engine MyISAM, understood to lock the entire table, can be read at the same time, write notRow level: Engine INNODB, separate one-line record lock
Table level, locking the entire table directly, and other processes cannot write to the table while you are locked out. If you are writing a lock, then the other processes are read and not allowedRow level, which locks only the specified record, so that other processes c
Overview of the LockWhy should I introduce a lock?Multiple users at the same timeThe concurrency of a database causes the following data inconsistencies:Missing updatesA,b two users read the same data and make changes, one of the user's changes to destroy the result of another change, such as booking systemDirty ReadA the user modified the data, then B users read out the data, but a user for some reason to cancel the modification of the data, data restore the original value, at this time the dat
Original address: http://hi.baidu.com/xublog/blog/item/6d090c22ffe227f5d6cae22b.html
5.4.3 CVS Annotate view
The CVS annotate view uses the same interface space as the CVS repositories view in the CVS Repository exploring perspective. The CVS annotate view is used to identif
An error occurred when submitting the statement using CVS today:
The specific prompt is as follows: CVS server: C:/Windows/temp/cvsc7.tmp: no such file or directory CVS [server aborted]: Error diffing test.txt.
According to the information on the Internet, there may be the following reasons: 1. after the cvsnt is installed, it is not restarted. 2. the path sett
MySQL row-level locks, table-level locks, page-level locks, mysql details
Page Level: Engine BDB. Table-level: Engine MyISAM, which is interpreted as locking the entire table. It can be read at the same time but cannot be written at the row level. Engine INNODB locks a single row of records and directly
CVS is a C/S system. Multiple developers use a central version control system to record file versions to ensure file synchronization. The working mode is as follows:
CVS server (file version Library)/| \(Same step for Version)/| \Developer 1 developer 2 Developer 3
As a general developer, you can select, And the CVS administrator needs to understand more. Fin
CVS is a C/S system. Multiple developers use a central version control system to record file versions to ensure file synchronization. The working mode is as follows:
CVS server (file version Library)/| \(Same step for Version)/| \Developer 1 developer 2 Developer 3
As a general developer, you can select, And the CVS administrator needs to understand more. Fin
operation by acquiring a lock to do the same data operation, which is similar to the Java synchronized, so pessimistic lock takes more time. In addition to the optimistic lock corresponding to the pessimistic lock is implemented by the database itself, to use, we directly call the database of related statements can be.Here, the two other lock concepts involved in the pessimistic lock come out, and they are shared locks and exclusive
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