Querying a DB in pgAdmin is quite straightforward. Locate your DB in the Servers dropdown on the left, and extend its dropdown, till you see the Schemas dropdown.Once you click on Schemas, the black button on the top, with the DB symbol and the play arrow will become clickable.Click on that button, and you will see a Query Tab open up. That’s it, you can type your queries for this particular DB in that box, and click the play arrow button to execute the queries.The output will be seen on the bottom, in the ‘Data Output’ section.Read More

Both Magnetic Tape and Magnetic Disk are the type of non-volatile magnetic memory and used to store the data. On the basis of architecture and features we can distinguish between both Magnetic Tape Memory and Magnetic Disk Memory. Following are the important differences between Magnetic Tape Memory and Magnetic Disk Memory.Sr. No.KeyMagnetic Tape MemoryMagnetic Disk Memory1DefinitionMagnetic tape is type of non-volatile memory uses thin plastic ribbon is used for storing data and as data use to be stored on ribbon so data read/write speed is slower due to which is mainly used for data backups.On other hand Magnetic Disk is ... Read More

Unix PipesUnix Pipes are used in inter-process communication. A pipe as name suggests provides a unidirectional flow of information. Data flows from one end to another.Message QueuesMessage queue allows to share messages by a sender process to another process (es). A message queue is implemented as a linked list of messages and stored within kernel. Each message has a unique message queue identifier. The kernel keeps a record of message queues present in the system.The following are some of the important differences between Unix Pipes and Message Queues.Sr. No.KeyPipeMessage Queue1ConceptThe pipe is the Unix IPC form to provide a flow ... Read More

When we surf the Internet, the webpages that we see and the contents that we download generally come from the "surface web". This is the part of the world wide web that is accessible to all with an Internet connection. The Surface Web is huge, but in reality, it covers only 10% of the whole Internet.Beside the Surface Web that is transparent and accessible to all, there are two more levels of the Internet that remain hidden in the background. These two are known as the Deep Web and the Dark Web.The deep web contains the web content that is ... Read More

Memory and Storage are two terms that are often used interchangeably, but they refer to different things. Memory is used to store data that is being actively used by the CPU, while Storage is used to store long-term data that needs to be accessed on a regular basis. Read this tutorial to learn more about Memory and Storage and how they are different from each other. What is Memory? Memory allows storing data on a short term basis. A memory normally is made up using registers. Each register has a location called memory location or storage location. Each memory location ... Read More

Both basic disk and dynamic disk are disk configurations available in Windows Operating System. A basic disk is from initial days of DOS, Windows to till date. Dynamic Disk is available from Window 2000 onwards.Basic DiskBasic Disk Configuration works on the concept of partition, partition table, and logical drives. A disk can have up to four partitions or three partitions and one extended partition with multiple logical drives. The following operations can be performed in basic disk configuration.Create/Delete primary/extended partition.Create/Delete logical drives within an extended partition.Format a partition and mark as active.Dynamic DiskDynamic Disk Configuration works on the concept of ... Read More

Primary KeyPrimary Key is a column that is used to uniquely identify each tuple of the table.It is used to add integrity constraints to the table. Only one primary key is allowed to be used in a table. Duplicate and NULL (empty) values are not valid in the case of the primary key. Primary keys can be used as foreign keys for other tables too.Let’s take an example, We have a table name employee which stores data of employees of a company. The below table shows the contents of the table.Emp_idNamePh_No.PositionSalaryEmp_id here is primary key of the table. As the ... Read More

Along with food, shelter and money internet and smart phone have become our basic necessities. Talking about smart phones along with all other criteria one unspoken necessity we all expect from our phone is front camera for selfies. A selfie for every mood, every moment happy, sad, angry or busy doing nothing.Earlier after taking a selfie limited editing options were available, but thanks to advancement in technology we can make our picture more beautiful or funny just as we want. A new app Lollicam helps us apply cinematic effects in selfies that makes picture more appealing. Pictures give you complete ... Read More

A data warehouse is a repository for structured, filtered data that has already been processed for a specific purpose. It collects the data from multiple sources and transforms the data using ETL process, then loads it to the Data Warehouse for business purpose. An operational database, on the other hand, is a database where the data changes frequently. They are mainly designed for high volume of data transaction. They are the source database for the data warehouse. Operational databases are used for recording online transactions and maintaining integrity in multi-access environments. Read this article to learn more about data warehouses ... Read More

This article helps us to add a new disk to LVM ( Logical Volume Manager), the very best advantage of LVM over normal disk partitions is its support for “dynamic partitions”; you can create and resize (expand or shrink) LVM volumes dynamically as we needed. There is no limit of the physical disk boundary in LVM logical volumes, so you can create a large LVM volume that spans across multiple smaller physical disks. This flexibility partitioning allows you to manage storage space more efficiently as disk usage change from time to time.If you want to add new disks to an ... Read More