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Articles by Hardik Gupta
Page 4 of 5
Commonly asked DBMS Interview Questions
To familiarize you with the kind of questions that may be asked during a job interview pertaining to the Database Management System, we will explore the most crucial DBMS Interview Questions in this post (DBMS). Q1)What are some uses for DBMS? The acronym DBMS, or database management system, stands for an application system whose primary function is around data. This system enables the user to design, save, retrieve, and update data as well as information about the data as it is stored in the database. Q2)What does the term "database" refer to? Simply said, a database is a collection of ...
Read MoreCommercial Data Mining Tools
These days, businesses have a wide range of tools at their disposal to use business intelligence software to transform raw data into actionable next actions. Some data mining technologies use machine learning techniques to accelerate this process. Modern data mining goes beyond basic analysis to more efficiently and effectively extract usable information from massive data volumes. Top 5 Data Mining tools in the Market RapidMiner Studio Data preparation, blending, visualization, and exploration are made easier using RapidMiner Studio, a visual data science workflow builder. Its predictive modeling and data mining initiatives are powered by machine-learning techniques Features Visual Workflow ...
Read MoreCombining Operations Using Pipelining
In a DSS workflow, a SQL pipeline is a procedure that mixes numerous subsequent recipes (each using the same SQL engine). Then, a single job activity containing these integrated recipes—which may be both visual and "SQL query" recipes—can be executed. Typically, a SQL query will be converted into an expression in relational algebra, which is a series of relational operations. If we do one operation at a time, we incur too much cost because we need to create temporary files on a disc to store the outcomes of these temporary operations. Large temporary files must be created and stored on ...
Read MoreCombine Rows into Strings in SQL, Server
In SQL Server, there are a number of different techniques to combine records into strings. Different methods to combine rows into a string which we will study in this tutorial − COALESCE XML PATH STRING_AGG First approach: COALESCE To combine many rows into a single string using the COALESCE method, first, create a variable of type varchar to hold the coalesced strings, then use a comma to separate each row's string values. Finally, apply the COALESCE to the variable. Syntax Select column_name1, column_name2, .. from table_name Declare @variable1 Varchar(MAX), @variable2 Varchar(MAX), ..; Select @variable1 = COALESCE(@variable1 ...
Read MoreColumnar Data Model of NoSQL
There is a rising trend toward using unconventional database types in an effort to efficiently accommodate the variety of data and fulfill the growing need for data storage. Relational databases have been the standard for many years. However, as markets evolve and storage costs decline, non-relational databases are becoming popular. Columnar databases are appropriate for this. These NoSQL databases were designed for challenging, intricate queries. Columnar databases, in contrast to relational databases, store data in columns instead of rows. Subgroups are created by combining these columns. This kind of database has movable keys and column names. The amount of rows ...
Read MoreClausal Form in Deductive Databases
A deductive database in SQL or any other database system is a tool that can draw conclusions about new facts based on the rules and information already present in the database. In deductive databases, datalog is the language commonly used to express facts, rules, and queries. The formula, when expressed in clausal form, consists of a number of clauses, each of which is made up of a number of literals joined exclusively by logical connectives marked with the OR symbol. The following quantifiers are possible in a formula − Universal quantifier − It may be read as "For all x, ...
Read MoreQuery Statistics in MySQL
The important statistics collected for a performed query, including time, temporary tables, indexes, joins, and more, are gathered in the Query Stats SQL editor results tab (see the following two figures). Requirements Enabled query, and collect performance schema statistics. The performance_schema has statement instrumentation enabled. SQL Editor: Query Stats Visual Explain Plan By utilizing the additional data included in the enhanced JSON format, the visual explain feature creates and presents a visual depiction of the MySQL EXPLAIN statement. All EXPLAIN formats, including the standard format, the raw extended JSON, and the visual query plan, are available in ...
Read MorePerformance Report Controls in Mysql Workbench
The controls listed below can be used to examine and export performance report data (see the following figure) − Export − Export all entries from the current performance report, including all queries and values, together with any associated data (including column headings). opens an export file dialogue. Copy Selected − Copies a single entry from the current performance report together with any related data (and column titles). the system's clipboard is saved. a case in point Query Copy − This function copies the SQL statement that produced the performance report. the system clipboard is saved. Refresh − The performance ...
Read MoreHow to Display System Variables of MySQL Server?
The MySQL system variable values are displayed using SHOW VARIABLES. There is no privilege required for this statement. Only the ability to connect to the server is necessary. Syntax SHOW [GLOBAL | SESSION] VARIABLES [LIKE 'pattern' | WHERE expr] A LIKE clause, if present, tells SHOW VARIABLES which variable names to match. To choose rows based on broader criteria, use a WHERE clause. An optional global or session variable scope modification is accepted by SHOW VARIABLES − The statement displays values for global system variables when GLOBAL is used as a modifier. For new connections ...
Read MoreHow do I disable Strict Mode in MySQL?
The handling of missing or incorrect values in queries that change the data is governed by MySQL Strict Mode. This contains the CREATE TABLE, UPDATE, and INSERT statements. When attempting to process the query with MySQL Strict Mode enabled, which is the default setting, invalid or missing data may result in warnings or failures. When Strict Mode is turned off, the identical query would have its missing or incorrect data modified and would result in a straightforward warning. This could appear to be the desired outcome, but with Strict Mode turned off, certain activities might have unanticipated effects. For instance, ...
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