metadata cleaner

Introduction to meta-data The most common definition of metadata (metadata) is "structural data about data," or, more simply, "information about data," which can be viewed as metadata in everyday life, such as illustrations, library catalogs, and business cards. In relational database management system (DBMS), metadata

What is MDLMdl,meta data lock, a metadata lock, is generally called a dictionary lock. The dictionary lock corresponds to a data lock. Dictionary lock is to protect the data object is changed, usually some DDL will change the Dictionary object, such as two things, things 1 query the table first, then the thing 2 to try to alter, which first need to wait for the end of things 1 (commit or rollback), at this time the state is waiting for table

meta-data management is essential in the process of data processing and warehouse construction, OEMM can address a variety of key business and technical challenges in the metadata management process, including how to manage metadata, understand the downstream impact of change data, and OEMM stand out in the browser from a business perspective. In the report, you can display the complete

Metadata (metadata): A series of special data tables that describe what is defined in the module and which are used to indicate what the managed module refers to. The purpose of the meta data: 1. At compile time, the metadata eliminates the need for the header and library files because all information related to the referenced type/member is included in the

Reading directory: 1. Introduction 2. Relationship between Model and View data context DataContext and View presentation) 3. Metadata-driven design how to use intermediate layer Metadata to drive final behavior) 4. How does ASP. NETMVC ModelMetadataModelMetadata metadata support the composite relationship between Model and View) 1. Introduction In this artic

ASP. NET MVC Model metadata (II)PrefaceIn the previous article, to leave an impression of the model metadata, there is no excessive explanation of the model metadata, and in this article does not explain the model metadata itself, but for its generation process, so that you can clearly understand when the system framew

Mysql metadata lock (2), mysqlmetadatalock The previous article mysql metadata lock (1) introduced some typical scenarios of MDL, MDL, and blocking caused by MDL locks. At last, the article left a small question. This article will introduce MDL in more detail, focusing on the Principle and Implementation of MDL. In general, commercial database systems implement locks. Generally, locks are divided into read

This article mainly introduces the metadata-sharing mode in the JavaScript design mode. If you are interested in the JavaScript design mode, refer to it. I. Definition The flyweight mode is a mode used for performance optimization. The core is to use the sharing technology to effectively support a large number of small scale objects.In JavaScript, browsers, especially mobile browsers, do not allocate much memory. It makes sense to save memory.The enj

Java Design Pattern modeling and implementation of cainiao series (21) enjoy metadata Pattern Flyweight: uses the sharing technology to effectively support a large number of fine-grained objects. The main purpose is to share objects, that is, the shared pool. When there are many objects in the system, the memory overhead can be reduced. To some extent, You can regard a singleton as a special case of Yuan-sharing.I. uml modeling: Ii. Code Implementa

The secret of metadata exchange bindingsWCF provides a special endpoint-the metadata exchange endpoint (MEX endpoint) through which services can publish metadata. In addition, it specializes in providing a meta data Exchange service contract interface IMetadataExchange:[ServiceContract]public interface IMetadataExchange{[OperationContract]Message Get (message req

There are two ways to publish service metadata: one is to provide metadata based on the Http-get protocol, which is a simple text-based protocol that is supported by most platforms, and the other is the metadata exchange endpoint.1. Based on the Http-get protocol2. Metadata Exchange Endpoint　　How C # WCF publishes

Yesterday I encountered a problem in the MySQL replication experiment: Database Version: 5.5.21-logOperating System: windows xp For master/slave replication, autocommit = 0 binlog-format = mixed tx-isolation = read-committed Experiment process:1.Create a table on the master:Create table t1 (a int) engine = innodb;2.Query on slave:Select * from t1;Empty set...Normal execution3.Delete a table on the master:Drop table t1;4.Query on slave:Select * from t1;Empty set...The results at this time are con

An error occurred while accidentally deleting the domain controller. Therefore, this error occurs when you rename the domain:Cannot connect and bind to the domain naming FSMO. cannot continue.: specified directoryThe Service property or value does not exist. 8202There is no way. You can only try to completely delete the domain controller metadata deleted by mistake:The procedure is as follows: 1. Click Start and point toProgram", Poin

Label:The last article, "MySQL metadata lock (i)," describes the reasons why the introduction of MDL,MDL action and the MDL lock lead to blocking several typical scenarios, the end of the article left a little doubt. This article will introduce the MDL in more detail, focusing mainly on the principle and implementation of MDL. In general, the business database system implements the lock, generally divides the lock into a read lock (shared lock) and a

The model metadata is a description of the data type itself and its property members, and the metadata has recursion (if the data is a complex type , the properties of the corresponding metadata describe the attributes of its properties).Purpose: Model of HTML rendering, model binding, model validation.Modelmetadata CustomHTML is rendered based on the properties

Tags: style color data for question CPresumably played MySQL to waiting for table metadata lock is certainly not unfamiliar, generally is the alter operation was blocked, resulting in the show processlist when we see the state of the thread is waiting for metadata lock. This article will make a small summary of MySQL metadata lock, hope to help you.The MDL was in

Since EF codefirst ctp4 has been used before, it is supported in the OEA framework on the third day of ef4.1 release. In addition, we are going to gradually replace the existing large-scale ORM framework and use the metadata system in EF to completely act as the ORM metadata in OEA, so that you can use the ing information to perform more operations. Since we have no time to take down the entire EF msdn, we

In many cases, many problems can be avoided or solved in theory or management, but when it comes to reality because management or coordination or the implementation of the standard is not enough, there will be a variety of problems that should not arise, usually in the production environment does not appear, But the reality is that no matter in any part, you have to find a solution, many times the reason is part, the preventive action is also a part, but the solution is also necessary, because i

Meta-Information for the database:First, let's introduce the meta-information of the database (metadata):Metadata (Metadata) is data about the data.Metadata is the data that describes the structure of data in a data warehouse and how to build it.What types of data are stored, what drives, etc., the data that describes the data is

This article is mainly for you in detail how Python preserves the metadata of the decorated function, hoping to help everyone. Case: The metadata for some functions is stored in the function object, such as: Name of f.__name__ function f.__doc__ function Documentation f.__moudle__ function belongs to module name f.__dict__ Property Dictionary f.__defaults__ Default parameter groups ...... When you access t