Results for "SQL Tuning"
136 / 136 posts
SQL Server Configuration Manager
Introduction Jab hum Microsoft SQL Server install karte hain , tab kuch important tools automatically install ho jate hain. Unme se ek bahut important tool…
Table Partitioning in SQL Server
Table Partitioning एक advanced database concept है जिसका उपयोग बड़े tables को छोटे, manageable हिस्सों (partitions) में बाँटने के लिए किया जाता है। इससे pe…
SQL Server System Databases
Introduction SQL Server me jab hum kaam karte hain, to generally hum tables, queries aur user databases par focus karte hain. Lekin ek hidden backbone hota…
SQL Server Index Optimization Automation (Missing & Unused Index Management)
Got it! Yeh lo plain content — seedha copy karo apne blog mein. Pehle workflow diagram, phir poora blog content.Pehle workflow diagram — screenshot leke blog m…
Implementing Transactions,Error Handling, and Dynamic SQL in SQL
Think of a transaction as a complete package deal. It's like when you buy something from a store. You give them money, and in return, you expect to get the…
SQL Interview Q&A
...onding answers extracted from the provided context: What is SQL? SQL stands for Structured Query Language. I…
TempDB in SQL Server
Introduction SQL Server me ek aisa database hai jo har query, har process aur almost har operation me involve hota hai. Ye ek temporary w…
SQL Server Administration – Management Tools Overview
Is section me hum mainly SQL Server ke management tools aur system databases ko samjhenge. SQL Server Management Tools Jab aap Microsoft SQL Server install…
Master Database in SQL Server
Introduction SQL Server me agar koi ek database sabse zyada critical hai, to wo hai: Master Database Ye SQL Server ka core brain hai. Agar master database …
Added columns in a table by dynamic ways
IF OBJECT_ID('AddedDynamicColumn','P') IS NOT NULL BEGIN DROP PROC AddedDynamicColumn END GO CREATE PROCEDURE AddedDynamicColumn AS BEGIN SELECT ED.empid,E…
Comparison of WHERE Clause Operators in MSSQL vs PostgreSQL
...of how operators in the WHERE clause are used in Microsoft SQL Server (MSSQL) vs PostgreSQL : Operator Purpose Used in MSSQL Used in Po…
SQL SQL Server Agent: Automation Ka Powerhouse in SQL ServerServer Agent
Agar aap production environment me kaam kar rahe ho, to aapko pata hoga ki kuch tasks aise hote hain jo baar-baar karne padte hain — jaise daily backup len…
MSDB Database in SQL Server
SQL Server me ek aur powerful system database hai jo automation + scheduling ka backbone hai: MSDB Database
SQL Server Management Studio (SSMS) – Complete Beginner Guide
SQL Server Management Studio Kya Hai? SQL Server Management Studio (SSMS) ek graphical interface (GUI tool) hai jisse aap SQL Server ke almost saare operat…
SQL Server Agent Alerts, Operators, Database Mail & Job Activity Monitor
Production environment me sirf jobs schedule karna hi kaafi nahi hota. Hume monitoring aur notification system bhi chahiye hota hai taaki agar koi job fail…
Understanding SQL Query for Identifying and Analyzing Default Values and Constraint in a Database
Default constraints in SQL are used to assign a default value to a column when no value is provided during data insertion. However, managing and auditing t…
What is Blocking in SQL, How to solve blocking, and Kill Session
What is Blocking in SQL? Blocking occurs in SQL Server when one query or transaction holds a lock on a resource (like a row or table) and prevents other qu…
SQL Server Deadlock & Performance Monitoring Made Easy
Learn how to detect SQL Server deadlocks and monitor performance with ready-to-use stored procedures for faster troubleshooting and optimization.
Statistics in SQL Server
Statistics SQL Server ke “mind” jaise hote hain. Ye SQL Server ko batate hain ki table me data kis tarah se distribute hai — jaise kitne values unique hain…
Database Backup in SQL Server
In SQL Server, taking a database backup is crucial for data recovery and protection. Here’s a basic guide on how to perform a database backup and restore i…
SQL Server Optimization Q&A
1. What is SQL Server Optimization? Answer: SQL Server Optimization ka matlab hota hai database ka performance better banana — jaise queries fast chalna, k…
Model & Resource Database in SQL Server
Introduction SQL Server ke system databases me kuch aise hidden heroes hote hain jo directly dikhte nahi, lekin bahut powerful role play karte hain. Aaj hum 2…
What is an Index? Explain its different types in SQL
✅ Index in SQL Server (इंडेक्स इन SQL सर्वर): Index SQL Server में एक database object (डेटाबेस ऑब्जेक्ट) है जो टेबल के डेटा को जल्दी से प्राप्त करने के लिए…
Pivoting and Unpivoting Data in SQL
Pivoting Data : Pivoting is the process of converting rows of data into columns, effectively changing the orientation of your data. It's useful when you ha…
Dynamic CREATE TABLE Script in SQL Server
DECLARE @TableName NVARCHAR(100) = 'Employee'; DECLARE @SQL NVARCHAR(MAX) = ''; DECLARE @PKCols NVARCHAR(MAX) = ''; -- Get Primary Key Column(s) SELECT @PK…
Understanding Stored Procedures in MSSQL
...hat is a Stored Procedure? A stored procedure is a group of SQL statements that are compiled and saved in the database. Instead of writing the same SQL qu…
The ALTER TABLE statement in Microsoft SQL Server (MSSQL) and PostgreSQL
The ALTER TABLE statement in Microsoft SQL Server (MSSQL) and PostgreSQL is used to modify the structure of an existing table. It allows you to: Add, drop,…
SQL Server Agent Jobs & Schedules – Complete Practical Guide (Step-by-Step)
Agar aap SQL Server me automation samajh chuke ho, to next logical step hai SQL Server Agent Jobs aur Schedules ko practically use karna . Is blog me hum d…
What are System Tables, File Tables, External Tables and Graph Tables in SQL Server
...bles Definition : System tables are internal tables used by SQL Server to store information about the database and server itself. These are met…
Understanding Data Types and Variables in MSSQL vs PostgreSQL
📊 Data Types Comparison Table 🚩 Category 🟦 MSSQL 🟨 PostgreSQL Integer Types INT , BIGINT , SMALLINT INTEGER , BIGINT , SMALLINT , SERIAL Decimal Types …
What difference between between MySQL and MSSQL
Feature MySQL MSSQL Ownership Oracle Corporation Microsoft Licensing Open-source (GPL) and commercial versions Commercial with free Express Edition Operati…
SQL Server Data type
SQL Server provides a variety of data types to store different kinds of data efficiently. Here are some commonly used SQL Server data types: CHAR(size): A …
JSON Data – Complete Conceptual Guide (SQL Server Perspective)
🔹 JSON kya hota hai? (Quick recap) JSON (JavaScript Object Notation) ek lightweight text format hota hai data exchange ke liye. Example: { "empId…
Filtering the data with TOP and OFFSET-FETCH In SQL
TOP: SELECT TOP (5) productid, unitprice FROM Production.Products WHERE categoryid = 1 ORDER BY unitprice DESC; SELECT TOP (5) WITH TIES productid, unitpri…
Index Rebuilding vs. Reorganization in SQL Server
As a database grows, maintaining optimal performance becomes crucial. One of the key contributors to performance degradation over time is index fragmentati…
Spark session vs Spark context
In Apache Spark, SparkSession and SparkContext are both essential components, but they serve different purposes and have different scopes. Here's a detaile…
Logical Query Processing Phases in SQL
SQL query processing consists of several logical phases, which describe the order in which SQL statements are evaluated. These phases help in understanding…
What is Functions and Difference between Functions and Stored Procedures in SQL Server
What is a Function in sql : A function is a set of SQL Statements that perform a specific task. Basically, it is a set of SQL statements that accept only i…
Triggers in SQL server
A trigger in SQL is a special type of stored procedure that runs automatically when certain actions happen in a table or view . A trigger cannot be explici…
What is a SQL Statement and types of SQL statements
A SQL (Structured Query Language) statement is a query or command used to perform various operations on data stored in a relational database. SQL statement…
Understanding Cursors in +SQL Server: A Complete Guide
When working with databases, most SQL operations are designed to handle large sets of data at once. However, there are cases where you may need to process …
What is the difference between DELETE and TRUNCATE statements in SQL?
...is the difference between DELETE and TRUNCATE statements in SQL? --DELETE and TRUNCATE are both SQL commands that can be used to remove data from a …
What are Constraints in SQL?
SQL में constraints डेटाबेस टेबल में डेटा को सुरक्षित और सही बनाए रखने के लिए उपयोग किए जाते हैं। ये टेबल में डेटा की वैधता (validity) और अखंडता (integrity…
Spark SQL useful command
Spark SQL provides a variety of commands for managing databases, tables, and performing SQL operations. CREATE DATABASE IF NOT EXISTS demo; SHOW DATABASES;…
What is View in SQL server
A view is a virtual table based on the result-set of an SQL statement. A view contains rows and columns, just like a real table. IF OBJECT_ID('ViewTable','…
SQL MERGE statement
CREATE DATABASE SqlShackMergeDemo GO USE SqlShackMergeDemo GO CREATE TABLE SourceProducts( ProductID INT, ProductName VARCHAR(50), Price DECIMAL(9,2) ) GO …
ANY and ALL operators used in SQL
The ANY operator: returns a boolean value as a result returns TRUE if any of the sub-query values meet the condition Any means that the condition will be t…
How to find table column information by using SQL query
...prehensive Guide to Fetching Table and Column Metadata with SQL Server Stored Procedures When working with databases, understanding the structure of tab…
How to comma separate value by using XML in SQL server
Before SQL Server 2017 (14.x), you can achieve the comma-separated values using the XML method. Here's an example of how you can achieve this: DECLARE @Sta…
XML Data – Complete Conceptual Guide (SQL Server Perspective)
How insert data on table from XML in SQL server, example: There are two method for insert data in table from XML. DECLARE @XMLInput VARCHAR(MAX); SET @XMLI…
SYS and INFORMATION_SCHEMA
sys In Microsoft SQL Server, the sys schema is a special schema that contains system views and stored procedures that provide metadata about the SQL Server…
Window Aggregate Functions in SQL
What is window function: Imagine you have a dataset with many rows, and you want to perform some calculations on each row based on a group of rows related …
SQL Logical Operators with Examples
SQL logical operators are used to filter data by combining multiple conditions in SQL queries. These operators help in refining queries to fetch specific r…
Understanding Locking Hints in SQL Server: NOLOCK, ROWLOCK, and UPDLOCK
...? Locking hints are special options you can include in your SQL queries to tell SQL Server how to handle locks on the data being quer…
Use of Apply(Cross and Outer) operator in SQL server
APPLY operator joins two table expressions. Also, I'll show how it differs from regular JOINs. Operator: CROSS APPLY Similar: INNER JOIN When to Use: Use a…
Table Types Comparison: SQL Server vs PostgreSQL
Table Type SQL Server PostgreSQL Scope / Lifetime Usage Notes Permanent Table CREATE TABLE Employee (...) CREATE TABLE Employee (...) Permanent in DB until…
Insert <br> tag in SQL text string
CREATE or ALTER FUNCTION dbo.Fn_InserBRtag(@inputString NVARCHAR(MAX)) RETURNS NVARCHAR(MAX) AS BEGIN DECLARE @resultString NVARCHAR(MAX) = ''; DECLARE @st…
UNION, UNION All, INTERSECT, EXCEPT used in SQL Server
UNION : The UNION operator is used to combine the result sets of two or more SELECT statements into a single result set. It removes duplicate rows from the…
Understanding Default Size of VARCHAR in SQL Server
Introduction When working with SQL Server, developers often use the VARCHAR data type to store variable-length character data. However, many overlook a cri…
How to use Magic (virtual) table INSERTED and DELETED in SQL server
...ual tables that are automatically created and maintained by SQL Server for each data modification operation performed on a table. They…
How to Two series with comma separate(any Delimiter) value split into in rows respectively
If we have two series with comma separate(any Delimiter) value and we want split into in rows, I have create function for that: IF OBJECT_ID('TF_SplitTwoSe…
How to get first date of given date or month.
Get First date of month: SELECT DATEFROMPARTS(YEAR(GETDATE()), MONTH(GETDATE()), 1) AS FirstDayOfCurrentMonth Create function for that IF NOT EXISTS (SELEC…
Database Permissions in SQL Server
In SQL Server, database permissions control what actions users can perform on specific database objects (like tables, views, and stored procedures). Permis…
WAITFOR in sql server
The WAITFOR statement in SQL Server is used to introduce a delay or wait period in the execution of a batch, transaction, or query. WAITFOR DELAY '00:00:05…
Find column in the whole database in sql server
To find a specific column in the whole database in SQL Server, you can query the information schema views. Here's a query you can use: SELECT table_name, c…
Order by index number in SQL
SELECT empid, lastname FROM HR.Employees ORDER BY 1 DESC --order by first column SELECT empid, lastname FROM HR.Employees ORDER BY 2 DESC --order by second…
SQL Server Multi-Level Approval Workflow with Auto Skip Logic
In many enterprise applications like HRMS, Travel Requests, Expense Approval, Purchase Approval , we need a multi-level approval workflow . But real system…
PySpark SQL Date and Timestamp Functions
🔧 Setup First (Optional for Reference) from pyspark.sql import functions as F from pyspark.sql import types as T data = df = spark.createDataFrame(data, )…
DBA
..., laptop, or workstation with Windows 10 installed. Install SQL S…
Variables In MySQL
...re used to store values temporarily during the execution of SQL queries. There are two main types of variables in MySQL: Session Variables : Ses…
Schema and Handling Corrupt data in PySpark
A schema in PySpark (and generally in data processing) defines the structure of a DataFrame, including the names and data types of each column. It serves a…
What is SQL and what is it used for?
SQL stands for Structured Query Language , and it is a standard programming language used for managing and manipulating data within relational databases. S…
Data archive in SQL Server
A data archive refers to the process of moving inactive or less frequently used data from an operational system to a storage system , typically in a separa…
Log Shipping (Ship Log) in SQL Server
Log Shipping in SQL Server is a high-availability feature that allows you to automatically send transaction log backups from a primary database on one serv…
How to use GOTO statement in SQL server
If you want to jump to a specific point in your SQL code, you can use the GOTO statement. The GOTO statement is used to exit a loop or a nested block of co…
What is Power BI
Power BI is a suite of business analytics tools developed by Microsoft that allows you to visualize and share insights from your data. Power BI consists of…
What is “CREATE TABLE TYPE” in SQL Server?
Ye ek User-Defined Table Type (UDTT) hota hai. Aap SQL Server me ek custom table ka design bana lete ho, jise aap baad me Stored Procedures, Functions, aur…
Applying Functions in PySpark
PySpark, the Python API for Apache Spark, provides multiple ways to apply functions to DataFrame columns. This flexibility allows data engineers and analys…
Data Import from text/CSV file in SQL Server
Step-by-Step Explanation 1. Checking and Dropping Existing Temporary Tables Before creating the temporary tables, the script ensures that any previously ex…
Store Error Logs In SQL
Create Table for Error log: CREATE TABLE [dbo].[ErrorLog]( [ErrorLogID] [int] IDENTITY(1,1) NOT NULL, [ErrorTime] [datetime] …
Split full name into first name and last name in SQL
Split full name into first name and last name : SELECT EmployeeName, CASE WHEN CHARINDEX(' ', EmployeeName) > 0 -- Check if there is a space (indicating…
All Date Components in SQL
We get First Date , Last date ,month number, month Name,Year, Financial Year(Finyear), and Month Year from Date (Date Range of each single date). SET DATEF…
PySpark Built-in Functions
These functions are commonly used with groupBy() , agg() , or select() to compute things like sum, average, max, min, count, etc. PySpark functions come fr…
How to one series with comma separate(any Delimiter) value split into in rows
If we have one series with comma separate(any Delimiter) value and we want split into in rows, I have create function for that: IF OBJECT_ID('TF_SplitSerie…
Functions in MySQL
In MySQL, a Function is similar to a Stored Procedure but with some key differences. Functions are used to perform calculations or operations and return a …
What are Data warehouse, Data Lake ,data mining and DataMart and MetaData
...panies ka data multiple sources me store hota hai, jaise: • SQL Server da…
Complex Data(StructType, ArrayType, and MapType) Types in PySpark
Great! Let’s break down PySpark's complex data types— StructType , ArrayType , and MapType —in a simple and clear way. We'll go over: What they are When to…
Database trigger to audit (Transaction logs) all of the DDL changes made to the Database
Create table DatabaseLog: CREATE TABLE [dbo].[DatabaseLog]( [DatabaseLogID] [int] IDENTITY(1,1) NOT NULL, [PostTime] [datetim…
Window Functions in PySpark
Window functions in PySpark allow you to perform operations across a set of rows that are somehow related to the current row. They are useful for tasks lik…
What is the Replication in MS SQL server
Replication is a way to copy data from one database to another and keep them in sync. This is useful when you want the same data available in multiple plac…
What difference between the DATEPART() and DATENAME() functions?
The difference between the DATEPART() and DATENAME() functions lies in their definitions. DATEPART() returns an integer that represents the specified datep…
Azure Data Factory (ADF)
Azure Data Factory (ADF) Kya Hai? Soch le tu ek delivery company chalata hai – jaise Swiggy/Zomato. Restaurant se khana uthaya → pack kiya → raste me check…
Stored Procedure in MySQL
...e_name (IN param1 data_type, OUT param2 data_type) BEGIN -- SQL statements END…
What is RLS (Row-Level Security) in Power BI
...Level Security, which is a feature in Power BI (and also in SQL Server Analysis Services) that allows you to restrict data access at the…
How to get first date From month and Finyear
If we have Finyear and month then we create a date for examples: DECLARE @finyear CHAR(5) = '202425'; DECLARE @month smallint = 5; --Get Year DECLARE @year…
Normalization in Databases
Normalization in a database is the process of organizing the data to reduce redundancy and improve data integrity. The main goal of normalization is to bre…
Database Shrink in SQL Server
Database shrink ka matlab hai database file (ya log file) ke size ko chhota karna by removing unused space . Matlab, agar tumhare DB me data delete ho gaya…
Data Pipeline and ETL (Extract, Transform, Load) Process/Tool and ELT
The ETL (Extract, Transform, Load) process/tool to collect, clean, and store data in a structured format. Extract (निकालना): सबसे पहले, डेटा को विभिन्न स्र…
Common Table Expressions (CTEs) in SQL
The Employee Hierarchy Problem Imagine you are working with an employee database where each employee might report to a manager. Here's a sample table struc…
MDF, NDF, LDF, and Filegroups
🔹 1. Filegroup kya hota hai? 🔸 Definition: Filegroup SQL Server में logical storage unit hota hai, jisme ek ya zyada data files hoti hain. Ye filegroups …
Working with Multiple Grouping Sets in SQL Server
🔍 1. Background - क्यों ज़रूरत पड़ी GROUPING SETS की? जब हमें एक ही query में अलग-अलग तरीके से data को group करके summary चाहिए होती है, तब हम GROUPING SE…
where() & filter() in PySpark
...aFrame by selecting rows that meet a specified condition or SQL expression. Alternatively, the …
PySpark Convert String to Array Column
...PySpark, you can use the split() function from the pyspark.sql.…
What is cluster in Spark
what is cluster : In computing, a cluster refers to a collection of interconnected computers that work together as a single system . These computers, often…
Databricks widgets
Input widgets allow you to add parameters to your notebooks and dashboards. You can add a widget from the Databricks UI or using the widget API. If y…
What is catalog in Spark
In Apache Spark, the catalog refers to the internal management system that keeps track of all the metadata related to tables, databases, functions, and oth…
How to use Window Functions in PySpark
Absolutely! Let’s break it down and explain each PySpark window function with examples using your code and dataset. I’ll categorize the functions into thre…
PaySpark Data manipulation
Select Table into dataframe: df = spark.read.table(tableName="samples.tpch.customer").limit(5) df = spark.table(tableName="samples.tpch.customer").limit(5)…
What is Data Ingestion and DataFrame API
Data ingestion : Data ingestion refers to the process of collecting, importing, and importing data from various sources into a system or storage environmen…
substring() in PySpark
📌 What is substring() ? The substring() function in PySpark is used to extract a portion of a string from a column in a DataFrame. It is part of the PySpa…
concat() and concat_ws() in PySpark
In PySpark, both concat() and concat_ws() are used to combine multiple columns into a single string column. ✅ concat() – Combines columns without any delim…
Azure Databricks command
Here are some common commands used in Databricks: %fs : Allows you to interact with the filesystem. For example, %fs ls lists the files in the current dire…
orderBy() and sort() in PySpark
...red manner. 1. Understanding sort() in PySpark from pyspark.sql.function…
PartitionBy() in PySpark
...ikhne (write) के time par use hota hai. ये function pyspark.sql.DataFrameWriter class ka part hai. �…
Join in PySpark
PySpark Join is used to combine two DataFrames and by chaining these you can join multiple DataFrames. # Syntax join(self, other, on=None, how=None) …
Joins in PySpark
They allow us to combine two or more DataFrames based on a common column, enabling efficient data processing and analysis. 1. PySpark Join Types Below are …
What is Data Lake
A data lake is a centralized repository that allows you to store all your structured and unstructured data at any scale. You can store your data as-is, wit…
Calculate and Calculatetable Function in Power BI
CALCULATE : It's used to modify or filter the context in which a calculation is being performed CALCULATE(<expression>, <filter1>, <filter2&…
DAX (Data Analysis Expressions) Operators and Data Type in Power BI
Here's the list of DAX operators in a table format: Arithmetic Operators Operator Description Example + Addition = + - Subtraction = - * Multiplication = *…
What is Data tables(Fact Tables) vs Lookup tables(Dimension Tables)
Data Tables(Fact Tables) Purpose : Store detailed, raw data. Structure : Multiple columns (attributes) and rows (records). Example : A table with order det…
Databricks, Apache Spark, Data Engineering and Science etc.
Azure Databricks is a platform on Microsoft Azure that helps with big data analysis and machine learning. It lets you work with large datasets easily and c…
Application,Job,Stage,Task in Spark
In Apache Spark, the execution of a program is broken down into multiple levels of granularity: applications, jobs, stages, and tasks. Understanding these …
How to Read and Write CSV file into DataFrame by using Pyspark
PySpark Read CSV File into DataFrame: reading CSV files from disk using PySpark offers a versatile and efficient approach to data ingestion and processing.…
Data Warehouse and Data Mining Syllabus
Yeh Data Warehouse and Data Mining ka complete syllabus list format me diya hai, bina explanation ke — sirf topics list: PART 1: Data Warehouse Syllabus Li…
select() Function in PySpark
In PySpark, select() function is used to select single, multiple, column by index, all columns from the list and the nested columns from a DataFrame, PySpa…
Understanding DataFrames in PySpark
DataFrames are an important data structure in PySpark. They help in handling structured and semi-structured data efficiently. DataFrames are like tables in…
How to Read and Write file into DataFrame by using Pyspark
# dataframe reader API.... spark.read.format("") \ .option("key":"value") \ .schema(schemavariable) \ .load() # dataframe write API...... spark.write.mode(…
In-Memory Databases (Data Warehouse Context)
🔹 In-Memory Database kya hoti hai? In-memory database wo database hoti hai jisme: 👉 Data hard disk par store nahi hota 👉 Data directly RAM (memory) me s…
PySpark Pivot and Unpivot DataFrame
✅ What is Pivot and Unpivot? Pivot = Convert rows into columns Unpivot = Convert columns into rows 🌀 Sample DataFrame Let’s start with a small DataFrame t…
union(), unionAll(), and unionByName() in PySpark
Here's the corrected explanation of union() , unionAll() , and unionByName() in PySpark along with appropriate examples. 1. union() The union() method is u…
drop(), dropDuplicates(), and distinct() in PySpark
🔹 1. drop() – Removing Columns The drop() function is used to remove one or more columns from a DataFrame. 👉 Example: Removing a Single Column from pyspa…
withColumn() in Pyspark
PySpark withColumn() is a transformation function of DataFrame which is used to change the value, convert the datatype of an existing column, create a new …
Understanding show() in PySpark
In PySpark, the .show() function is used to display DataFrame content in a tabular format. Syntax of show() DataFrame.show(n=20, truncate=True, vertical=Fa…
Seaborn
Seaborn is a powerful and easy-to-use data visualization library in Python built on top of Matplotlib. It's great for creating attractive and informative s…
What is Big Data
Big Data refers to extremely large datasets that are too complex and voluminous to be processed and analyzed using traditional data processing tools and te…
What is Managed and External table in Spark
In Apache Spark, both Managed and External tables are used to store the data. However, there are significant differences in how Spark manages the data for …