Diagram 2.0 displays the overall activity of the database. The diagram is explained below. • User request is accepted in the form of XMLs. Command XML and Data XML. • Command XML consists of commands that the database needs to carry out. It also contains user name and password for authentication purpose. • Once the user is authenticated, the Data XML is read. The location of Data XML is specified in Command XML. • The Data XML contains the data that needs to be added/updated to/deleted from the Database. • The Data XML might also contain queries that user wants the data from database. • The TestExec package will process the Data XML and depending upon the command, sends the XML object to Item Factory or Item Editor. • If the data is to be added …show more content…
into Database, Item Factory will generate keys. The keys generated are unique. • If the data needs to be updated to/deleted from Database, Item Editor will request TestExec to fetch data from database.
TestExec will in turn request the data from DBEngine. DBEngine will try to find the keys, metadata from IndexEngine. Then DBEngine will try to fetch the data from either in memory or from shards. • Once the data is received by Item Editor, it edits the data and sends it to DBEngine via TestExec. • The data is then added/updated to/deleted from database depending upon the request. • If the request is to fetch data from database, the TestExec will send the request to QueryEngine. • The QueryEngine will query the database for the data that is being asked for. • If the data requested is to fetch value of the particular key, then DBEngine requests for metadata from Index Engine. Once the metadata is received, the DBEngine will try to find the value from either Shard or from database. This information is stored in the metadata that is received from Index Engine. • If the data requested is to fetch keys from specified pattern. DBEngine will request keys from Index Engine and the same is being displayed to the user. • If the data requested is to fetch child keys, the DBEngine requests for metadata from Index Engine. The metadata contains the child key list. The data is then displayed to
user. • If the query sent is complex, then QueryEngine will split the query into simple queries and will execute one by one and will filter out the data which does not match the requested query. • User, Database, Scheduler can request for Sharding. Sharding is a mechanism of storing huge data into multiple smaller chunks so that the data retrieval is faster. • Once DBEngine gets a request for Sharding, it fetches keys and metadata from Index Engine and Data from database and shards (if available). • DBEngine checks for the data, if the data is new or needs to be updated or deleted. • If the data is new, then the new keys are added to Index Engine with their metadata. The actual data with keys and metadata is written to xml file with the help of PersistEngine. • If the data needs to be updated, the metadata will get updated in Index Engine. The data is then updated to shard with the help of PersistEngine. • If the data needs to be deleted, the key gets removed from Index Engine and a soft delete of the data is carried out.
The first database systems were based on the network and hierarchical models. A database can be defined as a collection of non-redundant data which can be shared by different application systems. A database implies separation of physical storage from use of the data by an application program to achieve program/data independence. Using a database system, the user or programmer or application specialist need not know the details of how the data are stored and such details are usually "transparent" to the user. .
Data provisioning manages the inventory of data and information, using relational database management systems and a data dictionary and data catalog. Transaction processing stores only the current data necessary to provide the status of current operations. Data provisioning receives, stores, and manages all validated transaction data from transaction processing. It also provides data back to transaction processing and information-to-information delivery when requested. Data dictionary and data catalog keep way of what data exists, where it is stored, what it means, and who has authority to access it. That helps data provisioning to protect the data and to provide access to data and information to those who need it.
Every application in the real world needs to interact with databases. Java Database Connectivity (JDBC) is the Application Programming Interface (API) used to build Java applications that can interact with relational databases. There are many relational databases such as Oracle, My SQL, DB2, Java DB, Dbase, Sybase, Ingress, Informix, FoxPro and so on. The researcher will be able to use the four types of JDBC drivers to interact with any kind of database in the world.
meta data - data about the data itself, such as logical database design or data dictionary definitions
Document database—taking the key-value concept and adding more complexity, each document in this type of database has its own data, and its own unique key, which is used to retrieve it. Examples: MongoDB, CouchDB.
Now that I know what I'm using to create my database I need to know
There is a database functionalities that perform consistency and efficiency of database. This function can be achieved by using the DBMS. First and foremost is DBMS as a data dictionary management that consist of definition for each data element and the relationship that been stored in a data dictionary. Means that all programs that access the data into database will work through the DBMS. The data dictionary will be used by DBMS to the require data component structure and its relationship.
Since its advent, databases have been among the most researched knowledge domains in computer science. Database is a generic term used to connote the collection of similar or related information/data in an organized and integrated manner such that can be easily accessed managed and updated. Kroenke 2010 refers to database as a collection of tables plus relationships among rows in those tables, plus special data (metadata) that describes the structure of the database. From the above we can simply define database as a repository of data meant to facilitate efficient and effective data storage, retrieval, maintenance and dissemination.
The script builds an SQL query by concatenating hard-coded strings together with a string entered by the user. The interpreter will execute the command based on the inputs received for the username and password fields. The code is not filtered for escape characters and the query is then passed into a SQL statement. The single and double quotes and the concatenation allow SQL injection. The code is vulnerable to SQL injection because the user is free to input anything they want in the form fields. A well crafted query string can manipulate the back-end database and log the user in even if they've not registered. Amending the query string can potentially delete or modify records in the database.
There are many functions a Database Management System (DBMS) serves that are key components to the operation of database management. When decide to perform a DBMS in business, first we must decide what type of DBMS we want. These are the ability to update and get back the data, Support Concurrent Updates, Recovery of Data, Security, ...
Like HTML, XML incorporates tags that bracket words and attributes. XML, however, uses these tags to define the data leaving the task of interpretation up to the application employing the data. This undefined vocabulary feature allows extensibility in that industry specific terminology is no longer a programming hurdle as in the past (Bos, 1999). XML applications can easily be tailored to plug in and bridge the communication between once stand-alone software. Resource intensive new software investments can be avoided by making use of existing databases and familiar programs.
Database management system is a computer program designed to manage a large set of structured data.
Well formed XML needs an additional step in order to properly validate the structure and vocabulary of the document. One method of this validation is using and XML schema, also known as the XML Schema Definition (XSD). (Barnette et al., 2004) Does this format for validation use the best structural methods to express vocabulary and properties in XML markup or could other options such as the DTD specification have provided similar benefits. The XSD structure and components should be discussed in detail in order to provide the best answer to this query.
Databases have been in use since the earliest days of electronic computing, but the vast majority of these were custom programs written to access custom databases. Unlike modern systems which can be applied to widely different databases and needs, these systems were tightly linked to the database in order to gain speed at the price of flexibility.
In order to access information from a database, it is required to have a database management system (DBMS). These systems are computer software applications that, in order to analyze the data, interact with the user and the database itself. The best known are [6]: