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Oracle Tutorial - How to add virtual column in oracle 11g
 
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Hello friends in this video i'm going to demonstrate you how to add virtual column in ORACLE 11g step by step. Oracle 11g supports virtual columns which are derived from the other columns in the table. You can use the virtual columns in your queries, you can index them, you can collect the statistics, etc. There are few restrictions on the virtual columns. You cannot write/insert the data into virtual columns. There is no support for index_organized, external, object, cluster, temporary tables.
Views: 1298 OCP Technology
Which Order Should Columns Go in an Index?: Finding All the Red Sweets Part 4
 
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When you create an index on multiple columns there's an important question you need to answer: In which order should you list the columns? This video looks at some of the factors you should consider to help answer this question. ============================ The Magic of SQL with Chris Saxon Copyright © 2015 Oracle and/or its affiliates. Oracle is a registered trademark of Oracle and/or its affiliates. All rights reserved. Other names may be registered trademarks of their respective owners. Oracle disclaims any warranties or representations as to the accuracy or completeness of this recording, demonstration, and/or written materials (the “Materials”). The Materials are provided “as is” without any warranty of any kind, either express or implied, including without limitation warranties or merchantability, fitness for a particular purpose, and non-infringement.
Views: 3775 The Magic of SQL
Database Design 39 - Indexes (Clustered, Nonclustered, Composite Index)
 
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This video covers the basics of indexes. Indexing is an extremely important step of database design. Without Indexes database queries can take a substantial amount of time and hog system resources. The main two classifications of indexes are clustered and non-clustered indexes. Clustered indexes are usually the primary key and determine how the data is actually stored in the table. These are the fastest and most effective. Non-clustered indexes sort a reference to data that is still fast but doesn't actually determine how the data is structured. The best tip I can give you is to use indexes but don't over use them. Having loads of indexes on columns that are barely ever in a where clause or join can bog down the database. This is because every time the table is updated the index must also be updated! When a database looks through a table for certain where conditions on a column that does not have an index, it does an entire table scan. This is not a good practice for large databases (or even small databases but not as bad). With an index the database will do an index seek and quickly find the data you are looking for. Composite indexes consist of two or more columns within one index. Use these when you plan on using the two columns together for a database query WHERE clause. Learn more about indexes here: https://www.calebcurry.com/blogs/database-design/introduction-to-indexes Donate!: http://bit.ly/DonateCTVM2. Courses for Download: http://www.udemy.com/u/calebcurry/ (Use the coupon code "YouTubeDiscount" without the quotes) Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://Twitter.com/calebCurry Subscribe (it's free!): https://www.youtube.com/channel/UCZUyPT9DkJWmS_DzdOi7RIA?sub_confirmation=1 Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 88690 Caleb Curry
Multiple Indexes on the Same Set of Columns
 
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This video demonstrates how you can use invisible indexes to allow multiple indexes on the same set of columns. Multiple indexes on the same column set is a new feature in Oracle 12c. For more information see: https://oracle-base.com/articles/12c/multiple-indexes-on-same-set-of-columns-12cr1 Website: https://oracle-base.com Blog: https://oracle-base.com/blog Twitter: https://twitter.com/oraclebase Cameo by Scott Spendolini Blog: http://spendolini.blogspot.co.uk/ Twitter: https://twitter.com/sspendol Website: http://www.sumnertech.com/ Cameo appearances are for fun, not an endorsement of the content of this video.
Views: 1211 ORACLE-BASE.com
SQL 12c Tutorial 20 : SQL 12c Creating Multiple Indexes on column
 
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SQL 12c Tutorial 20 : SQL 12c Creating Multiple Indexes on column SQL 12c New Features SQL 12c Tutorial for beginners Oracle 12c Tutorial for beginners Creating Multiple indexes on column
Views: 484 TechLake
Alter database table columns without dropping table   Part 67
 
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In this video, we will discuss, altering a database table column without having the need to drop the table. Let's understand this with an example. Text version of the video http://csharp-video-tutorials.blogspot.com/2013/08/part-67-alter-database-table-columns.html Slides http://csharp-video-tutorials.blogspot.com/2013/09/part-67-alter-database-table-columns.html All SQL Server Text Articles http://csharp-video-tutorials.blogspot.com/p/free-sql-server-video-tutorials-for.html All SQL Server Slides http://csharp-video-tutorials.blogspot.com/p/sql-server.html All Dot Net and SQL Server Tutorials in English https://www.youtube.com/user/kudvenkat/playlists?view=1&sort=dd All Dot Net and SQL Server Tutorials in Arabic https://www.youtube.com/c/KudvenkatArabic/playlists We will be using table tblEmployee for this demo. Use the sql script below, to create and populate this table with some sample data. Create table tblEmployee ( ID int primary key identity, Name nvarchar(50), Gender nvarchar(50), Salary nvarchar(50) ) Insert into tblEmployee values('Sara Nani','Female','4500') Insert into tblEmployee values('James Histo','Male','5300') Insert into tblEmployee values('Mary Jane','Female','6200') Insert into tblEmployee values('Paul Sensit','Male','4200') Insert into tblEmployee values('Mike Jen','Male','5500') The requirement is to group the salaries by gender. To achieve this we would write a sql query using GROUP BY as shown below. Select Gender, Sum(Salary) as Total from tblEmployee Group by Gender When you execute this query, we will get an error - Operand data type nvarchar is invalid for sum operator. This is because, when we created tblEmployee table, the "Salary" column was created using nvarchar datatype. SQL server Sum() aggregate function can only be applied on numeric columns. So, let's try to modify "Salary" column to use int datatype. Let's do it using the designer. 1. Right click on "tblEmployee" table in "Object Explorer" window, and select "Design" 2. Change the datatype from nvarchar(50) to int 3. Save the table At this point, you will get an error message - Saving changes is not permitted. The changes you have made require the following tables to be dropped and re-created. You have either made changes to a table that can't be re-created or enabled the option Prevent saving changes that require the table to be re-created. So, the obvious next question is, how to alter the database table definition without the need to drop, re-create and again populate the table with data? There are 2 options Option 1: Use a sql query to alter the column as shown below. Alter table tblEmployee Alter column Salary int Option 2: Disable "Prevent saving changes that require table re-creation" option in sql server 2008 1. Open Microsoft SQL Server Management Studio 2008 2. Click Tools, select Options 3. Expand Designers, and select "Table and Database Designers" 4. On the right hand side window, uncheck, Prevent saving changes that require table re-creation 5. Click OK
Views: 86451 kudvenkat
SQL with Oracle 10g XE - Using ALTER TABLE to Modify Table Columns
 
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In this video I use the ALTER TABLE command to modify an existing field column. The command will allow you to change the data types, whether the field can be null, or even the primary key. When using the ALTER TABLE command you would use the keyword MODIFY to make changes to an existing column. Be careful when changing a data type of the null field as existing data may cause an error if not in compliance with the new change. The code I used to alter the Books table is : ALTER TABLE BOOKS MODIFY ISBN_10 VARCHAR(13); This video is part of a series of videos with the purpose of learning the SQL language. For more information visit Lecture Snippets at http://lecturesnippets.com.
Views: 15364 Lecture Snippets
07 04 Index Column Order Matters
 
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ORACLE
Views: 61 oracle ocm
BITMAP  and  BITMAP JOIN INDEX IN ORACLE explained
 
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The video explains BITMAP and BITMAP JOIN INDEX IN ORACLE and when you should create them on a column. BITMAP INDEXES should be dealt with carefully as they can lead to serious performance issues if the table is updated by multiple processes in parallel. Indexing Basics :https://www.youtube.com/watch?v=0X9bbtwTnuE&t=1095s Star and snowflake Schema :https://www.youtube.com/watch?v=Qq4yhhAk9fc&t=17s
Views: 2352 Tech Coach
SQL Tutorial - 13: Inserting Data Into a Table From Another Table
 
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In this tutorial we'll learn to use the INSERT Query to copy data from one table into another.
Views: 234394 The Bad Tutorials
Clustered vs. Nonclustered Index Structures in SQL Server
 
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Clustered and nonclustered indexes share many of the same internal structures, but they're fundamentally different in nature. Watch Microsoft Certified IT Professional Jon Seigel explain the similarities and differences of clustered and nonclustered indexes, using a real-world example to show how these structures work to improve the performance of SQL queries. Blog post on primary key vs. the clustered index: http://voluntarydba.com/post/2012/10/02/The-Primary-Key-vs-The-Clustered-Index.aspx CREATE INDEX statement reference: http://technet.microsoft.com/en-us/library/ms188783.aspx ALTER INDEX statement reference: http://technet.microsoft.com/en-us/library/ms188388.aspx Index navigation internals by example: http://sqlblog.com/blogs/paul_white/archive/2011/08/09/sql-server-seeks-and-binary-search.aspx Sample index data is from the AdventureWorksLT2008R2 sample database: http://awlt2008dbscript.codeplex.com/releases/view/46169 Visit my channel for more database administration videos: https://www.youtube.com/voluntarydba Subscribe to get notified about my latest videos: https://www.youtube.com/voluntarydba?sub_confirmation=1 Read additional content on my blog: http://voluntarydba.com Follow on Twitter: https://twitter.com/voluntarydba Like on Facebook: https://facebook.com/voluntarydba
Views: 273891 Voluntary DBA
11-How to create an index for a column in a table in a SQL Server database
 
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Original high quality video: http://www.dotnetcodecentral.com/Post/130/microsoft-sql-server-quick-learn-how-to/How-to-create-an-index-for-a-column-in-a-SQL-Server-table All high quality videos on SQL Server (FREE to download): http://www.dotnetcodecentral.com/Technology/microsoft-sql-server-quick-learn-how-to Demonstrates the following (using SQL Server Management Studio): -Open a table in design mode (to modify table structure) -Add an index to a column in a table
Views: 16198 Jagadish Pulakhandam
SQL Server 2016 Column Store Index e InMemory Tables
 
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En este video vemos las mejoras de Column Store Index de InMemory Tables en SQL Server 2016 Ing. Eduardo Castro, PhD http://ecastrom.blogspot.com Microsoft SQL Server MVP
Views: 453 Eduardo Castro
Oracle Database11g tutorials 8 || SQL DISTINCT with multiple columns |SQL Distinct with Two columns
 
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This SQL tutorial and Oracle database 11g tutorial for beginners will show how to use SQL DISTINCT keyword with SQL Select clause. This Video is in the continuation of previous video on SQL distinct with one column. In this video we will see How to use SQL distinct with multiple columns and SQL distinct with two columns Tool used in this tutorial is SQL developer. This tutorial series is part of SQL expert exam certification training. If you are preparing for SQL certification you can use my tutorials. This SQL Tutorial is a part of free training. Copy Cloud referral link || Use this link to join copy cloud and get 20GB of free storage https://copy.com?r=j7eYO7 Contacts Email [email protected] Twitter https://twitter.com/rebellionrider Instagram http://instagram.com/rebellionrider Facebook. https://www.facebook.com/imthebhardwaj Linkedin. in.linkedin.com/in/mannbhardwaj/ Thanks for linking, commenting, sharing and watching more of our videos This is Manish From The Code makers
Views: 96499 Manish Sharma
How To Add New Column(Field) in Existing table Using Oracle Database
 
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In this video You will learn how to Add new column after creating a new table or existing tables in oracle database , This video help us adding one or more than columns as per project requirement. add a column add a column in a table add a column in sql add a column in table add a column sql add a column to a table add a column to an existing table add a column to sql table add a column to table add a new column add column add column alter table add column in a table add column in a table oracle add column in existing table add column in oracle add column in sql add column in table add column in table oracle add column in table sql add column into table add column ms sql add column oracle add column oracle sql add column oracle table add column pl sql add column sql add column sql oracle add column sql script add column sql server add column sql server 2008 add column sql server 2012 add column table add column table oracle add column to a table add column to a table sql add column to database add column to existing table add column to existing table sql server add column to oracle table add column to sql add column to sql server table add column to sql table add column to table add column to table oracle add column to table sql add column to table sql server add column to table sql server 2008 add column tsql add field sql add field sql server add field to table sql add new column add new column in existing table add new column in oracle database tables add new column in table sql add new column sql add new column to sql table add new column to table add new column to table oracle add new column to table sql add sql column add table column add to table sql alter a table sql alter table alter column sql alter table change column sql alter table column sql alter table command sql table add column sql table alter sql update table add column sql update table column sqlplus alter table table add column table alter table columns add update add column update column oracle update table add column update table add column oracle update table add column sql
Views: 2340 Programming Lifestyle
What is Index Scan ,Index Seek and Table Scan?
 
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An index scan or table scan is when SQL Server has to scan the data or index pages to find the appropriate records. index seek happens when data is searched among the index.Please watch full video for detail.
Views: 16980 SqlIsEasy
07 05 Demo   Index Column Order
 
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ORACLE
Views: 47 oracle ocm
SQL Server 33 - Indexes
 
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Indexes allow us to tell the database that certain columns are columns we want to retrieve commonly. This allows the database to optimize retrieval. Additionally, when we get into the SELECT statement, we will often have to join data from multiple tables. When we correctly add indexes to our tables, we can improve the speed of our SELECT and also our joins. There are two types of Index. One is called clustered and the other is called non-clustered. Clustered indexes determine the actual order of the table. By default this is going to be the primary key column. So when you label a column as PRIMARY KEY, you are also going to be creating an INDEX that is a clustered index. A clustered index is kind of like a telephone book, where the data is right there when you look up a phone number. This means that if you are just making a small database that is only going to store a few things, you may be fine. But more likely than not you are going to want to add additional indexes. When you add a new index, you create a non-clustered index. These things do not actually determine the order of the rows in the table. A way of how you can think of how these work is like an index in the back of a book. The index of the book does not actually contain the data, it just tells you where to find it. What columns do you index? You are going to want every primary key to be indexed. What about foreign keys, are they indexed by default? No, they are not. Of all columns, you are probably going to want to index the foreign keys the most because they are used in joins. Lastly, you will likely want to index columns that you are going to use on a regular basis. You can also make composite indexes just like you can make composite keys. You would want to do this when you are going to constantly being using those columns together. There is a lot to learn on multicolumn indexes. We may explore this concept in more detail and see how SQL Server uses them in a future video, but as of right now it's probably more important that we get a general understanding of all things SQL Server before we deep dive on something like that. In the upcoming videos I'll be teaching you how to create indexes. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Support me! http://www.patreon.com/calebcurry Subscribe to my newsletter: http://bit.ly/JoinCCNewsletter Donate!: http://bit.ly/DonateCTVM2. ~~~~~~~~~~~~~~~Additional Links~~~~~~~~~~~~~~~ More content: http://CalebCurry.com Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://twitter.com/calebCurry Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 7093 Caleb Curry
Indexing in Oracle :B-Tree,Bitmap Indexing
 
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This Video is the 1st tutorial in the video series Indexing in Oracle , The video series explains in detail, What are indexes?It's types, what index should be used in which scenario and other important thing in basic terminology. Note :You may want to watch the video with a higher playback speed(1.25 if it suits you more)
Views: 10094 Tech Coach
Get Table Names with Column Names and Data Types in SQL Server - SQL Server Tutorial
 
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In this video ,we will generate the script that will return us all the table names with column names and data type of those columns. We often need this information. Let's say we are going to prepare mapping document for load the data from Source Database to Destination database. We can get the list of all tables with column names and data types from Source Database and Destination Database and then paste in Excel and map the required input columns to output columns for ETL Process. Blog link with scripts used in video http://sqlage.blogspot.com/2015/02/get-all-tables-with-column-names-and.html
Views: 42172 TechBrothersIT
PL/PDF Oracle table rows and columns in PDF
 
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How to implement the DOCX template for Oracle table printing in PDF. website: http://www.plpdf.com twitter: http://twitter.com/plpdf linkedin: https://www.linkedin.com/company/pl-pdf facebook: http://facebook.com/plpdf
Views: 853 PL/PDF
How to create Virtual Columns in Oracle Database
 
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How to create Virtual Columns in Oracle Database 12c When queried, virtual columns appear to be normal table columns, but their values are derived rather than being stored on disc. The syntax for defining a virtual column is listed below. column_name [datatype] [GENERATED ALWAYS] AS (expression) [VIRTUAL] If the datatype is omitted, it is determined based on the result of the expression. The GENERATED ALWAYS and VIRTUAL keywords are provided for clarity only. The script below creates and populates an employees table with two levels of commission. It includes two virtual columns to display the commission-based salary. The first uses the most abbreviated syntax while the second uses the most verbose form. CREATE TABLE employees ( id NUMBER, first_name VARCHAR2(10), last_name VARCHAR2(10), salary NUMBER(9,2), comm1 NUMBER(3), comm2 NUMBER(3), salary1 AS (ROUND(salary*(1+comm1/100),2)), salary2 NUMBER GENERATED ALWAYS AS (ROUND(salary*(1+comm2/100),2)) VIRTUAL, CONSTRAINT employees_pk PRIMARY KEY (id) ); INSERT INTO employees (id, first_name, last_name, salary, comm1, comm2) VALUES (1, 'JOHN', 'DOE', 100, 5, 10); INSERT INTO employees (id, first_name, last_name, salary, comm1, comm2) VALUES (2, 'JAYNE', 'DOE', 200, 10, 20); COMMIT; Querying the table shows the inserted data plus the derived commission-based salaries. SELECT * FROM employees; ID FIRST_NAME LAST_NAME SALARY COMM1 COMM2 SALARY1 SALARY2 ---------- ---------- ---------- ---------- ---------- ---------- ---------- ---------- 1 JOHN DOE 100 5 10 105 110 2 JAYNE DOE 200 10 20 220 240 2 rows selected. SQL The expression used to generate the virtual column is listed in the DATA_DEFAULT column of the [DBA|ALL|USER]_TAB_COLUMNS views. COLUMN data_default FORMAT A50 SELECT column_name, data_default FROM user_tab_columns WHERE table_name = 'EMPLOYEES'; COLUMN_NAME DATA_DEFAULT ------------------------------ -------------------------------------------------- ID FIRST_NAME LAST_NAME SALARY COMM1 COMM2 SALARY1 ROUND("SALARY"*(1+"COMM1"/100),2) SALARY2 ROUND("SALARY"*(1+"COMM2"/100),2) 8 rows selected. SQL Notes and restrictions on virtual columns include: 1)Indexes defined against virtual columns are equivalent to function-based indexes. 2)Virtual columns can be referenced in the WHERE clause of updates and deletes, but they cannot be manipulated by DML. 3)Tables containing virtual columns can still be eligible for result caching. 4)Functions in expressions must be deterministic at the time of table creation, but can subsequently be recompiled and made non-deterministic without invalidating the virtual column. In such cases the following steps must be taken after the function is recompiled: a)Constraint on the virtual column must be disabled and re-enabled. b)Indexes on the virtual column must be rebuilt. c)Materialized views that access the virtual column must be fully refreshed. d)The result cache must be flushed if cached queries have accessed the virtual column. e)Table statistics must be regathered. 5)Virtual columns are not supported for index-organized, external, object, cluster, or temporary tables. 6)The expression used in the virtual column definition has the following restrictions: a.It cannot refer to another virtual column by name. b.It can only refer to columns defined in the same table. c.If it refers to a deterministic user-defined function, it cannot be used as a partitioning key column. e.The output of the expression must be a scalar value. It cannot return an Oracle supplied datatype, a user-defined type, or LOB or LONG RAW.
Views: 415 OracleDBA
mysql tutorial for beginners (6/8) : Indexes
 
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mysql tutorial for beginners (6/8) : Indexes As things stand, the table students works and can be searched without problem by MySQL—until it grows to more than a couple of hundred rows, At that point, database accesses will get slower and slower with every new row added, because MySQL has to search through every row whenever a query is issued. This is like searching through every book in a library whenever you need to look something up. Of course, you don’t have to search libraries that way, because they have either a card index system or, most likely, a database of their own. The way to achieve fast searches is to add an index, either when creating a table or at any time afterward. But the decision is not so simple. For example, there are different index types such as a regular INDEX, PRIMARY KEY, and FULLTEXT. Also, you must decide which columns require an index, a judgment that requires you to predict whether you will be searching any of the data in that column. And even when you’ve decided that, you still have the option of reducing index size by limiting the amount of each column to be indexed. If we imagine the searches that may be made on the students table, it becomes apparent that all of the columns may need to be searched. Anyway, go ahead and add an index to each of the columns, using the commands: ALTER TABLE students ADD INDEX(name(3)); An alternative to using ALTER TABLE to add an index is to use the CREATE INDEX command. They are equivalent, except that CREATE INDEX cannot be used for creating a PRIMARY KEY CREATE INDEX surname ON students (surname(5)); DESCRIBE students; These commands create indexes on both the name and surname columns, limiting name index to only the first 3 characters, and surname index to the first 5 characters. For instance, when MySQL indexes the following name: SAFAA It will actually store in the index only the first 3 characters: SAF This is done to minimize the size of the index, and to optimize database access speed. DESCRIBE command shows the key MUL for each column. This key means that multiple occurrences of a value may occur within that column, which is exactly what we want, as name or surname may appear many times. You don’t have to wait, until after creating a table to add indexes. In fact, doing so can be time-consuming, as adding an index to a large table can take a very long time. Therefore, let’s look at a command that creates the table students with indexes already in place. CREATE TABLE students ( Id_studnet SMALLINT UNSIGNED NOT NULL AUTO_INCREMENT, name VARCHAR(10) NOT NULL, surname VARCHAR(20) NOT NULL, email VARCHAR(30) NOT NULL, INDEX(name(3)), INDEX(surname(5)), ,PRIMARY KEY(id_studnet),UNIQUE(email)); Another important index, PK, its single unique key for each student to enable instant accessing of a row. The importance of having a key with a unique value for each row will come up when we start to combine data from different tables. You can add PK, while you create the table at the first time, or later by issuing the following command: ALTER TABLE students ADD PRIMARY KEY(id_student); The last important index, FULLTEXT index Unlike a regular index, MySQL’s FULLTEXT allows super-fast searches of entire columns of text. It stores every word in every data string in a special index that you can search using “natural language,” in a similar manner to using a search engine. It’s not strictly true that MySQL stores all the words in a FULLTEXT index, because it has a built-in list of more than 500 words that it chooses to ignore because they are so common that they aren’t very helpful for searching anyway. This list, called stopwords, includes the, as, is, of, and so on. The list helps MySQL run much more quickly when performing a FULLTEXT search and keeps database sizes down. FULLTEXT indexes can be created for CHAR, VARCHAR, and TEXT columns only. A FULLTEXT index definition can be given in the CREATE TABLE statement when a table is created, or added later using ALTER TABLE (or CREATE INDEX). Adding a FULLTEXT index to the table students for the columns name and surname ALTER TABLE classics ADD FULLTEXT(name,surname); this index is in addition to the ones already created and does not affect them You can now perform FULLTEXT searches across this pair of columns. If you find that MySQL is running slower than you think it should be when accessing your database, the problem is usually related to your indexes. Either you don’t have an index where you need one, or the indexes are not optimally designed. Tweaking a table’s indexes will often solve such a problem. In the next tutorial, we will learn about, using FOREIGN KEY Constraints and how to join tables together. Subscribe for more: ---------------------------------------------------------------------------- https://www.youtube.com/subscription_center?add_user=saf3al2a SWE.Safaa Al-Hayali - saf3al2a
Views: 25020 Safaa Al-Hayali
Oracle SQL Tutorial 14 - Column-Level and Table-Level Constraints
 
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In the previous video we talked about adding constraints at the column-level. We made it nice and simple by only requiring a few keywords, but the problem we were having is that we could not assign a name to the constraint, which many people like to do so we can reference easily if we need to at a later time. To do this, it requires a little bit more typing, but it will give us extra flexibility and many consider it to be the higher quality approach to adding constraints. Let's go though a simple example. Let's say we have a users table with a user_id column that we want to make a primary key. We will create the table like this: CREATE TABLE( user_ id NUMBER PRIMARY KEY ) Instead of adding the PRIMARY KEY keywords after the data type, we add: CONSTRAINT user_pk PRIMARY KEY Now, we have assigned the name user_pk to this constraint. You can do the same with other constraints, such as UNIQUE. The syntax would be CONSTRAINT username_un UNIQUE. The other way to create constraints requires to put all of our constraints at the bottom of our table creation rather than inline with the column. This type of constraint is known as a table-level constraints. To make a column a primary key using table-level constraints, we add it to the CREATE TABLE command as if it is another row and use the CONSTRAINT keyword to tell Oracle that what is coming is a constraint, not a column in our table. CREATE TABLE users( user_id NUMBER, username VARCHAR2(50 CHAR), CONSTRAINT username_un UNIQUE (username), CONSTRAINT users_pk PRIMARY KEY (user_id) ) The primary differences here is that you have to put the column you are talking about in parenthesis after the PRIMARY KEY keyword. That's because it's at the end of the table and you need a way to tell it what column you are talking about. The option of putting it at the end of the table has the added benefit in this situation because if we needed to have a primary key that is the combination of multiple columns, we can do that by just adding the other column in the PRIMARY KEY parenthesis right after a comma. In summary, there are three ways to make constraints. The first is at the column level, unnamed. The second is at the column level, named. The third is at the table level, also named. In the next video we are going to create a named constraint in Oracle SQL Developer, so stay tuned and be sure to subscribe! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Support me! http://www.patreon.com/calebcurry Subscribe to my newsletter: http://bit.ly/JoinCCNewsletter Donate!: http://bit.ly/DonateCTVM2. ~~~~~~~~~~~~~~~Additional Links~~~~~~~~~~~~~~~ More content: http://CalebCurry.com Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://twitter.com/calebCurry Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 13039 Caleb Curry
SQL: pseudo columns (Rowid/Rownum)
 
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In this tutorial, u'll learn the difference between rowid & rownum..
Views: 29750 radhikaravikumar
002 Virtual Columns
 
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Views: 293 Kartik Mundhra
SQL tutorial 23: Rename and Modify Column Using Alter Table By Manish Sharma (RebellionRider)
 
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How to Rename a column of a table using alter table and How to modify a column of a table using alter table Modify means How to change datatype of a column and how to change size/width of a column Web Article link http://bit.ly/sql-tutorial23 Tutorial 21 How to rename a table : http://bit.ly/sql-tutorial-21 Tutorial 22 How to add/ delete column: http://bit.ly/sql-tutorial-22 YouTube Video on How to create database http://bit.ly/create-database-using-DBCA Tool used in this tutorial is SQL Developer. This tutorial series is part of SQL expert exam certification training. if you are preparing for SQL certification you can use my tutorials. This SQL Tutorial is a part of free training. Copy Cloud referral link || Use this link to join copy cloud and get 20GB of free storage https://copy.com?r=j7eYO7 Contacts E-Mail [email protected] Twitter https://twitter.com/rebellionrider Instagram http://instagram.com/rebellionrider Facebook. https://www.facebook.com/imthebhardwaj Linkedin. http://in.linkedin.com/in/mannbhardwaj/ Thanks for liking, commenting, sharing and watching more of our videos This is Manish from RebellionRider.com
Views: 43436 Manish Sharma
What Impact Do Indexes Have on Inserts?: Finding All the Red Sweets Part 0
 
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Creating indexes can improve query performance. Oracle must maintain the indexes however. This increases the work it must do whenever you modify data in indexed columns. In this video Chris looks at this overhead using a real world analogy - recording the color of all the candies stored in party bags! ============================ The Magic of SQL with Chris Saxon Copyright © 2015 Oracle and/or its affiliates. Oracle is a registered trademark of Oracle and/or its affiliates. All rights reserved. Other names may be registered trademarks of their respective owners. Oracle disclaims any warranties or representations as to the accuracy or completeness of this recording, demonstration, and/or written materials (the “Materials”). The Materials are provided “as is” without any warranty of any kind, either express or implied, including without limitation warranties or merchantability, fitness for a particular purpose, and non-infringement.
Views: 2542 The Magic of SQL
Oracle tutorial : How to create Id with AUTO INCREMENT in Oracle PL SQL
 
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Oracle tutorial: How to create Id with AUTO INCREMENT in Oracle oracle tutorial for beginners sequence in oracle identity key in sql In this Oracle tutorial , we can create an auto increment field using ‘sequence’ object that can be assigned as primary keys. Using Oracle ‘sequence’ object, you can generate new values for a column. An Oracle sequence is an object like a table or a stored procedure. Examples CREATE SEQUENCE SYSTEM.MYSEQ START WITH 1 MAXVALUE 999999999999999999999999999 MINVALUE 1 NOCYCLE CACHE 20 NOORDER; CREATE OR REPLACE TRIGGER TR_CITY BEFORE INSERT ON CITY FOR EACH ROW BEGIN SELECT LPAD(LTRIM(RTRIM(TO_CHAR(myseq.NEXTVAL))),10,'0') INTO :NEW.id FROM DUAL; END; / Subscribe on youtube: https://www.youtube.com/channel/UCpiyAesWNYOXSz5GPq8lbkA For more tutorial please visit #techquerypond https://techquerypond.wordpress.com https://twitter.com/techquerypond
Views: 8477 Tech Query Pond
Oracle SQL Tutorial 11 - CREATE TABLE
 
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The way you create a table is to use the CREATE TABLE command. CREATE TABLE users() So in this situation, the name comes right after the TABLE keyword. The next thing we do is put all of the columns on a line that we want to put in our table. CREATE TABLE users( user_id, username, first_name, last_name ) Notice the naming conventions here. For this series we are going to make columns with what is known as snake casing. This is where each individual word is separated by an underscore. if you have more than one column, all of them have to have commas except the last one. The comma is a way to say that another column is coming, so you don't need to do it on the last one. Now you would think we were done, but we also have to say what data type each column is. Later we will extensively discuss data types so we can focus on them exclusively. For now, here are the data types we are going to use: CREATE TABLE users( user_id NUMBER, username VARCHAR2(50), first_name VARCHAR2(50), last_name VARCHAR2(50) ) Now, inside of the parenthesis for varchar2, we pass in a number... This is the max length of the string. But the question is, what is it measured in? The default is actually in bytes, not characters. For example if we have the string hello, it is 5 characters, but it might take up a total of 10 bytes of storage. So I would recommend adding the keyword char right after the number so it defaults to 50 characters, not bytes. CREATE TABLE users( user_id NUMBER, username VARCHAR(50 CHAR), first_name VARCHAR2(50 CHAR), last_name VARCHAR2(50 CHAR) ) This will work to create a table, but it's really missing a lot of information… which column is the primary key? Are we adding any indexes? Is there any thing else we need to say about these columns? So as you can tell, we are making progress, but there is still so much to learn. The biggest gotcha to remember from this video is that the data type VARCHAR ends in a 2, stupid, right? who would end the name of something with a 2? Once again, this is Caleb from CalebTheVideoMaker2, and we will catch you in the next one! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ HELP ME! http://www.patreon.com/calebcurry Subscribe to my newsletter: http://bit.ly/JoinCCNewsletter Donate!: http://bit.ly/DonateCTVM2. ~~~~~~~~~~~~~~~Additional Links~~~~~~~~~~~~~~~ More content: http://CalebCurry.com Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://twitter.com/calebCurry Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 27972 Caleb Curry
SQL Server Tutorial 23: Partitioning Tables and Indexes
 
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How to partition a table and an index using SSMS, or T-SQL. For more info, or a copy of the scripts used in this tutorial, please email me at [email protected]
Views: 19051 Johnny Deluca
Oracle Pseudo Column, Virtual Column , Invisible Column and Unused Column
 
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More Details at, Pseudo Column @ https://www.youtube.com/edit?o=U&video_id=GIGmZwShGh4 Virtual Column @ https://www.youtube.com/edit?o=U&video_id=qUALFDzLDJw Invisible Column @ https://www.youtube.com/edit?o=U&video_id=nz48CdgDCt4 Unused Column @ https://www.youtube.com/edit?o=U&video_id=GWo4VcNZo6Y
Views: 85 Siva Academy
Indexes in sql server   Part 35
 
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In this video we will learn about What are indexes Why do we use indexes Advantages of indexes These concepts are applicable to sql server 2000, 2005 and 2008 Text version of the video http://csharp-video-tutorials.blogspot.com/2012/09/indexes-in-sql-server-part-35.html Slides http://csharp-video-tutorials.blogspot.com/2013/08/part-35-indexes.html All SQL Server Text Articles http://csharp-video-tutorials.blogspot.com/p/free-sql-server-video-tutorials-for.html All SQL Server Slides http://csharp-video-tutorials.blogspot.com/p/sql-server.html All Dot Net and SQL Server Tutorials in English https://www.youtube.com/user/kudvenkat/playlists?view=1&sort=dd All Dot Net and SQL Server Tutorials in Arabic https://www.youtube.com/c/KudvenkatArabic/playlists
Views: 356693 kudvenkat
Clustered and nonclustered indexes in sql server   Part 36
 
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In this video we will learn about 1. Different types of indexes in sql server 2. What are clustered indexes 3. What are NonClustered indexes 4. Difference between clustered and non clustered indexes Text version of the video http://csharp-video-tutorials.blogspot.co.uk/2012/09/clustered-and-non-clustered-indexes.html Slides http://csharp-video-tutorials.blogspot.com/2013/09/part-36-clustered-nonclustered-indexes.html All SQL Server Text Articles http://csharp-video-tutorials.blogspot.com/p/free-sql-server-video-tutorials-for.html All SQL Server Slides http://csharp-video-tutorials.blogspot.com/p/sql-server.html All Dot Net and SQL Server Tutorials in English https://www.youtube.com/user/kudvenkat/playlists?view=1&sort=dd All Dot Net and SQL Server Tutorials in Arabic https://www.youtube.com/c/KudvenkatArabic/playlists
Views: 438173 kudvenkat
Oracle tutorial : Pseudo columns in Oracle PL SQL (pseudo column)
 
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Oracle tutorial : Pseudo columns in Oracle PL SQL ( pseudocolumn ) oracle tutorial for beginners rownum in oracle This video will show you what is Pseudo columns in Oracle PL SQL. Pseudo columns are likes ROWNUM, ROENUM, ROWID, NEXTVAL,SYSDTAE , USER etc. pseudocolumn examples Oracle tutorial : Pseudo columns in oracle Oracle supports several special-purpose data elements that are not actually contained in a table, but are available for use in SQL statements. Here is a partial list of pseudo-columns in Oracle a)CURRVAL : When using Oracle SEQUENCE values, the pseudo-column CURRVAL returns the current value of the sequence. for example: schema.sequence_name.CURRVAL b)NEXTVAL :When using Oracle SEQUENCE values, the pseudo-column NEXTVAL returns the next value of the sequence and causes the sequence to increment by one. for example: schema.sequence_name.NEXTVAL c)ROWNUM:ROWNUM returns a number indicating the order in which a row was selected from a table. d)ROWID: ROWID returns the rowid (binary address) of a row in a database table. e)USER :This pseudo-column will always contain the Oracle username under which you are connected to the database. f)SYSDATE:This pseudo-column will contain the current date and time. This column is a standard Oracle DATE datatype. The value represents the current time on the server not the client. For more tutorial please visit #techquerypond https://techquerypond.com https://techquerypond.wordpress.com https://twitter.com/techquerypond
Views: 1347 Tech Query Pond
Oracle tutorial : What is Virtual column in Oracle PL SQL
 
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This video will show you " Oracle tutorial: What is Virtual column in Oracle PL SQL " sql calculated field computed column oracle-11g-new-feature-virtual-column Oracle tutorial : What is Virtual column in oracle Syntax : column_name [datatype] [GENERATED ALWAYS] AS [expression] [VIRTUAL] 1)The values of the virtual column are not stored in the database. 2)You can not update the values of virtual column. 3)when you try to modify it will give oracle error. 4)These are read only values. 5)Virtual columns used in the WHERE clause of UPDATE and DELETE statement 6)Constraints can be created on them. #techquerypond https://techquerypond.wordpress.com https://twitter.com/techquerypond
Views: 1336 Tech Query Pond
Part 6   Transform rows into columns in sql server
 
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Link for all dot net and sql server video tutorial playlists http://www.youtube.com/user/kudvenkat/playlists Link for slides, code samples and text version of the video http://csharp-video-tutorials.blogspot.com/2014/06/part-6-transform-rows-into-columns-in.html This is another common sql server interview question. We will be using Countries table in this example. SQL to create the table Create Table Countries ( Country nvarchar(50), City nvarchar(50) ) GO Insert into Countries values ('USA','New York') Insert into Countries values ('USA','Houston') Insert into Countries values ('USA','Dallas') Insert into Countries values ('India','Hyderabad') Insert into Countries values ('India','Bangalore') Insert into Countries values ('India','New Delhi') Insert into Countries values ('UK','London') Insert into Countries values ('UK','Birmingham') Insert into Countries values ('UK','Manchester') Here is the interview question. Write a sql query to transpose rows to columns. Using PIVOT operator we can very easily transform rows to columns. Select Country, City1, City2, City3 From ( Select Country, City, 'City'+ cast(row_number() over(partition by Country order by Country) as varchar(10)) ColumnSequence from Countries ) Temp pivot ( max(City) for ColumnSequence in (City1, City2, City3) ) Piv
Views: 179052 kudvenkat
[Creating Indexes] 3 - Creating an index on computed column
 
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Creating Indexes Given a SQL Server table named Customer_Details and Calc_Area in the ABC_Bank database,you will view and practice how to create a unique index on a computed column using Transact-SQL. 1 - Creating an unique index 2 - Creating composite index 3 - Creating an index on computed column Learn more at : http://www.tutorialspoint.edu.vn/sql-server/162-types-of-indexes/12610-workshop-types-of-indexes.html
Views: 346 little fire
Oracle Virtual Column vs pseudo column
 
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Oracle Virtual Column vs pseudo column Details on pseudo column @ https://youtu.be/GIGmZwShGh4 Details on Virtual Column @ https://youtu.be/qUALFDzLDJw
Views: 23 Siva Academy
Oracle Database 12c demos: In-Memory Column Store Architecture Overview
 
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The demonstration provides an overview of the architecture of the In-Memory Column Store feature introduced in Oracle Database 12c Release 1 patchset 1.
How to use partitioning to improve performance of large tables
 
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In this video we cover in much more detail the improvement in performance that can be achieved by using partitioning. MS SQL server databases can scale well using this feature. We cover how partitioning a table gives similar performance as a single table with a clustered index, we then explore how adding NC index improve performance of the heap table as well as the partitioned table.
Views: 17319 Jayanth Kurup
SQL: Delete Vs Truncate Vs Drop
 
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In this tutorial, you'll learn the difference between delete/drop and truncate. PL/SQL (Procedural Language/Structured Query Language) is Oracle Corporation's procedural extension for SQL and the Oracle relational database. PL/SQL is available in Oracle Database (since version 7), TimesTen in-memory database (since version 11.2.1), and IBM DB2 (since version 9.7).[1] Oracle Corporation usually extends PL/SQL functionality with each successive release of the Oracle Database. PL/SQL includes procedural language elements such as conditions and loops. It allows declaration of constants and variables, procedures and functions, types and variables of those types, and triggers. It can handle exceptions (runtime errors). Arrays are supported involving the use of PL/SQL collections. Implementations from version 8 of Oracle Database onwards have included features associated with object-orientation. One can create PL/SQL units such as procedures, functions, packages, types, and triggers, which are stored in the database for reuse by applications that use any of the Oracle Database programmatic interfaces. PL/SQL works analogously to the embedded procedural languages associated with other relational databases. For example, Sybase ASE and Microsoft SQL Server have Transact-SQL, PostgreSQL has PL/pgSQL (which emulates PL/SQL to an extent), and IBM DB2 includes SQL Procedural Language,[2] which conforms to the ISO SQL’s SQL/PSM standard. The designers of PL/SQL modeled its syntax on that of Ada. Both Ada and PL/SQL have Pascal as a common ancestor, and so PL/SQL also resembles Pascal in several aspects. However, the structure of a PL/SQL package does not resemble the basic Object Pascal program structure as implemented by a Borland Delphi or Free Pascal unit. Programmers can define public and private global data-types, constants and static variables in a PL/SQL package.[3] PL/SQL also allows for the definition of classes and instantiating these as objects in PL/SQL code. This resembles usage in object-oriented programming languages like Object Pascal, C++ and Java. PL/SQL refers to a class as an "Abstract Data Type" (ADT) or "User Defined Type" (UDT), and defines it as an Oracle SQL data-type as opposed to a PL/SQL user-defined type, allowing its use in both the Oracle SQL Engine and the Oracle PL/SQL engine. The constructor and methods of an Abstract Data Type are written in PL/SQL. The resulting Abstract Data Type can operate as an object class in PL/SQL. Such objects can also persist as column values in Oracle database tables. PL/SQL is fundamentally distinct from Transact-SQL, despite superficial similarities. Porting code from one to the other usually involves non-trivial work, not only due to the differences in the feature sets of the two languages,[4] but also due to the very significant differences in the way Oracle and SQL Server deal with concurrency and locking. There are software tools available that claim to facilitate porting including Oracle Translation Scratch Editor,[5] CEITON MSSQL/Oracle Compiler [6] and SwisSQL.[7] The StepSqlite product is a PL/SQL compiler for the popular small database SQLite. PL/SQL Program Unit A PL/SQL program unit is one of the following: PL/SQL anonymous block, procedure, function, package specification, package body, trigger, type specification, type body, library. Program units are the PL/SQL source code that is compiled, developed and ultimately executed on the database. The basic unit of a PL/SQL source program is the block, which groups together related declarations and statements. A PL/SQL block is defined by the keywords DECLARE, BEGIN, EXCEPTION, and END. These keywords divide the block into a declarative part, an executable part, and an exception-handling part. The declaration section is optional and may be used to define and initialize constants and variables. If a variable is not initialized then it defaults to NULL value. The optional exception-handling part is used to handle run time errors. Only the executable part is required. A block can have a label. Package Packages are groups of conceptually linked functions, procedures, variables, PL/SQL table and record TYPE statements, constants, cursors etc. The use of packages promotes re-use of code. Packages are composed of the package specification and an optional package body. The specification is the interface to the application; it declares the types, variables, constants, exceptions, cursors, and subprograms available. The body fully defines cursors and subprograms, and so implements the specification. Two advantages of packages are: Modular approach, encapsulation/hiding of business logic, security, performance improvement, re-usability. They support object-oriented programming features like function overloading and encapsulation. Using package variables one can declare session level (scoped) variables, since variables declared in the package specification have a session scope.
Views: 58996 radhikaravikumar
List Oracle Database Schemas, Tables, Columns and table contents using Angularjs and JSP.
 
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This is a basic dba tutorial about getting contents on Oracle database objects like procedures, functions, package spec, package bodies, triggers and many more. This application dynamically load schemas and load object type when schema selected and object name when object type selected and when object name is selected you get the content of the object. You can even compile the object with a little compile button below, although it might not work properly everytime. Link to source code : https://drive.google.com/open?id=0BznrW3lgX0ozcElkeTVzREdFeUU
Views: 409 Subhroneel Ganguly
Oracle Database Indexes: Myths, Tips and Tricks
 
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In this tutorial, OCM John Watson will - via demonstrations - debunk these myths: Myth #1: Oracle Database does not index NULL Myth #2: A search that includes wildcards can't use an index if the wildcard precedes the string. Myth #3: Oracle will not use a function-based index unless the FBI is coded in the predicate. Myth #4: Indexes always help. The more indexes the better. See http://skillbuilders.com/free-oracle-tutorials for gigabytes of free Oracle video tutorials.
Views: 16071 SkillBuilders
How to create Foreign Key Constraint on Multiple Columns in SQL Server - SQL Server Tutorial Part 67
 
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SQL Server / TSQL Tutorial Scenario: You are working as SQL Server developer, you need to create a table dbo.Customer with composite primary key by using columns FName and SSN. One you are done with creating primary key in dbo.Customer table, you need to create second table dbo.Orders and create foreign key constraint by using Primary Key columns. Link to scripts used in SQL Server / TSQL Tutorial Video http://www.techbrothersit.com/2016/04/how-to-create-foreign-key-constraint-on.html Check out our website for Different SQL Server, MSBI tutorials and interview questions such as SQL Server Reporting Services(SSRS) Tutorial SQL Server Integration Services(SSIS) Tutorial SQL Server DBA Tutorial SQL Server / TSQL Tutorial ( Beginner to Advance) http://www.techbrothersit.com/
Views: 4404 TechBrothersIT

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