This presentation gives a clear and concise description of joins in sql and several types of sql joins.
These slides also contains the pictorial representation as well as syntax for each type of joins.
YouTube Link: https://youtu.be/f6VWSlnHGCE
** MySQL DBA Certification Training: https://www.edureka.co/mysql-dba **
This Edureka PPT on 'SQL Triggers' will help you understand the concept of triggers in SQL. Below are the topics covered in this SQL Triggers For Beginners.
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MySql Triggers Tutorial - The Webs Academythewebsacademy
A SQL trigger is a set of SQL statements stored in the database catalog. A SQL trigger is executed or fired whenever an event associated with a table occurs e.g., insert, update or delete.
This presentation gives a clear and concise description of joins in sql and several types of sql joins.
These slides also contains the pictorial representation as well as syntax for each type of joins.
YouTube Link: https://youtu.be/f6VWSlnHGCE
** MySQL DBA Certification Training: https://www.edureka.co/mysql-dba **
This Edureka PPT on 'SQL Triggers' will help you understand the concept of triggers in SQL. Below are the topics covered in this SQL Triggers For Beginners.
Follow us to never miss an update in the future.
YouTube: https://www.youtube.com/user/edurekaIN
Instagram: https://www.instagram.com/edureka_learning/
Facebook: https://www.facebook.com/edurekaIN/
Twitter: https://twitter.com/edurekain
LinkedIn: https://www.linkedin.com/company/edureka
Castbox: https://castbox.fm/networks/505?country=in
MySql Triggers Tutorial - The Webs Academythewebsacademy
A SQL trigger is a set of SQL statements stored in the database catalog. A SQL trigger is executed or fired whenever an event associated with a table occurs e.g., insert, update or delete.
ACID properties
Atomicity, Consistency, Isolation, Durability
Transactions should possess several properties, often called the ACID properties; they should be enforced by the concurrency control and recovery methods of the DBMS.
Using and Creating SQL Functions with Ammar Hassan Brohi.
String Functions
Numeric Functions
String / Number Conversion Functions
Group Functions
Date and Time Functions
Date Conversion Functions
Consists of the explanations of the basics of SQL and commands of SQL.Helpful for II PU NCERT students and also degree studeents to understand some basic things.
In DBMS (DataBase Management System), the relation algebra is important term to further understand the queries in SQL (Structured Query Language) database system. In it just give up the overview of operators in DBMS two of one method relational algebra used and another name is relational calculus.
This presentation deals with the fundamentals of SQL, Installation and Database concepts. Presented by our team in Alphalogic Inc: https://www.alphalogicinc.com/
Just about anyone can write a basic SQL query for a table. Not everyone can write a good query though - that takes practice and knowing how to understand what the optimizer is doing with the query. Learn the basics of query optimization so you keep your application engaging the user rather then showing the progress bar as they wait on the database.
ACID properties
Atomicity, Consistency, Isolation, Durability
Transactions should possess several properties, often called the ACID properties; they should be enforced by the concurrency control and recovery methods of the DBMS.
Using and Creating SQL Functions with Ammar Hassan Brohi.
String Functions
Numeric Functions
String / Number Conversion Functions
Group Functions
Date and Time Functions
Date Conversion Functions
Consists of the explanations of the basics of SQL and commands of SQL.Helpful for II PU NCERT students and also degree studeents to understand some basic things.
In DBMS (DataBase Management System), the relation algebra is important term to further understand the queries in SQL (Structured Query Language) database system. In it just give up the overview of operators in DBMS two of one method relational algebra used and another name is relational calculus.
This presentation deals with the fundamentals of SQL, Installation and Database concepts. Presented by our team in Alphalogic Inc: https://www.alphalogicinc.com/
Just about anyone can write a basic SQL query for a table. Not everyone can write a good query though - that takes practice and knowing how to understand what the optimizer is doing with the query. Learn the basics of query optimization so you keep your application engaging the user rather then showing the progress bar as they wait on the database.
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
The Indian economy is classified into different sectors to simplify the analysis and understanding of economic activities. For Class 10, it's essential to grasp the sectors of the Indian economy, understand their characteristics, and recognize their importance. This guide will provide detailed notes on the Sectors of the Indian Economy Class 10, using specific long-tail keywords to enhance comprehension.
For more information, visit-www.vavaclasses.com
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
2. The Setting
• Database systems are normally being
accessed by many users or processes at
the same time.
– Both queries and modifications.
• Unlike operating systems, which support
interaction of processes, a DMBS needs
to keep processes from troublesome
interactions.
3. Example: Bad Interaction
• You and your domestic partner each take
$100 from different ATM’s at about the
same time.
– The DBMS better make sure one account
deduction doesn’t get lost.
• Compare: An OS allows two people to edit
a document at the same time. If both
write, one’s changes get lost.
4. ACID Transactions
• A DBMS is expected to support “ACID
transactions,” processes that are:
– Atomic : Either the whole process is done or
none is.
– Consistent : Database constraints are
preserved.
– Isolated : It appears to the user as if only one
process executes at a time.
– Durable : Effects of a process do not get lost if
the system crashes.
5. Transactions in SQL
• SQL supports transactions, often
behind the scenes.
– Each statement issued at the generic
query interface is a transaction by itself.
– In programming interfaces like Embedded
SQL or PSM, a transaction begins the first
time a SQL statement is executed and
ends with the program or an explicit
transaction-end.
6. COMMIT
• The SQL statement COMMIT causes a
transaction to complete.
– It’s database modifications are now
permanent in the database.
7. ROLLBACK
• The SQL statement ROLLBACK also
causes the transaction to end, but by
aborting.
– No effects on the database.
• Failures like division by 0 or a
constraint violation can also cause
rollback, even if the programmer does
not request it.
8. An Example: Interacting Processes
• Assume the usual Sells(bar,beer,price)
relation, and suppose that Joe’s Bar sells
only Bud for $2.50 and Miller for $3.00.
• Sally is querying Sells for the highest and
lowest price Joe charges.
• Joe decides to stop selling Bud and
Miller, but to sell only Heineken at $3.50.
9. Sally’s Program
• Sally executes the following two SQL
statements, which we call (min) and
(max), to help remember what they do.
(max)
SELECT MAX(price) FROM Sells
WHERE bar = ’Joe’’s Bar’;
(min)
SELECT MIN(price) FROM Sells
WHERE bar = ’Joe’’s Bar’;
10. Joe’s Program
• At about the same time, Joe executes the
following steps, which have the mnemonic
names (del) and (ins).
(del) DELETE FROM Sells
WHERE bar = ’Joe’’s Bar’;
(ins) INSERT INTO Sells
VALUES(’Joe’’s Bar’, ’Heineken’, 3.50);
11. Interleaving of Statements
• Although (max) must come before (min),
and (del) must come before (ins), there
are no other constraints on the order of
these statements, unless we group Sally’s
and/or Joe’s statements into transactions.
12. Example: Strange Interleaving
• Suppose the steps execute in the order
(max)(del)(ins)(min).
Joe’s Prices:
2.50, 3.00 2.50, 3.00
3.50
Statement:
(max)
(del)
(ins)
(min)
Result:
3.00
• Sally sees MAX < MIN!
3.50
13. Fixing the Problem by Using
Transactions
• If we group Sally’s statements (max)(min)
into one transaction, then she cannot see
this inconsistency.
• She sees Joe’s prices at some fixed time.
– Either before or after he changes prices, or in
the middle, but the MAX and MIN are
computed from the same prices.
14. Another Problem: Rollback
• Suppose Joe executes (del)(ins), not as
a transaction, but after executing these
statements, thinks better of it and
issues a ROLLBACK statement.
• If Sally executes her statements after
(ins) but before the rollback, she sees a
value, 3.50, that never existed in the
database.
15. Solution
• If Joe executes (del)(ins) as a transaction,
its effect cannot be seen by others until
the transaction executes COMMIT.
– If the transaction executes ROLLBACK
instead, then its effects can never be seen.
16. Isolation Levels
• SQL defines four isolation levels =
choices about what interactions are
allowed by transactions that execute at
about the same time.
• How a DBMS implements these isolation
levels is highly complex, and a typical
DBMS provides its own options.
17. Choosing the Isolation Level
•
Within a transaction, we can say:
SET TRANSACTION ISOLATION LEVEL X
where X =
1.
2.
3.
4.
SERIALIZABLE
REPEATABLE READ
READ COMMITTED
READ UNCOMMITTED
18. Serializable Transactions
• If Sally = (max)(min) and Joe = (del)(ins) are
each transactions, and Sally runs with
isolation level SERIALIZABLE, then she will
see the database either before or after Joe
runs, but not in the middle.
• It’s up to the DBMS vendor to figure out how
to do that, e.g.:
– True isolation in time.
– Keep Joe’s old prices around to answer Sally’s
queries.
19. Isolation Level Is Personal Choice
• Your choice, e.g., run serializable,
affects only how you see the database,
not how others see it.
• Example: If Joe Runs serializable, but
Sally doesn’t, then Sally might see no
prices for Joe’s Bar.
– i.e., it looks to Sally as if she ran in the
middle of Joe’s transaction.
20. Read-Commited Transactions
• If Sally runs with isolation level READ
COMMITTED, then she can see only
committed data, but not necessarily the
same data each time.
• Example: Under READ COMMITTED, the
interleaving (max)(del)(ins)(min) is
allowed, as long as Joe commits.
– Sally sees MAX < MIN.
21. Repeatable-Read Transactions
• Requirement is like read-committed, plus:
if data is read again, then everything seen
the first time will be seen the second time.
– But the second and subsequent reads may
see more tuples as well.
22. Example: Repeatable Read
• Suppose Sally runs under REPEATABLE
READ, and the order of execution is (max)
(del)(ins)(min).
– (max) sees prices 2.50 and 3.00.
– (min) can see 3.50, but must also see 2.50
and 3.00, because they were seen on the
earlier read by (max).
23. Read Uncommitted
• A transaction running under READ
UNCOMMITTED can see data in the
database, even if it was written by a
transaction that has not committed (and
may never).
• Example: If Sally runs under READ
UNCOMMITTED, she could see a price
3.50 even if Joe later aborts.