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oracle world - Row Level Lock in Oracle database
 
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Hello friends in this video we learn how the lock occur in database automatically when multiple user modified the same transaction in their session. Oracle database Unbeatable,Unbreakable Platform..
Views: 6770 Oracle World
Differences between Shared and Exclusive Lock in oracle database
 
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Hello friends in this video we learn how the lock occur in database automatically when multiple user modified the same transaction in their session. Oracle database Unbeatable,Unbreakable Platform..
Views: 9725 Oracle World
01 Oracle database Table lock
 
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Purpose Use the LOCK TABLE statement to lock one or more tables, table partitions, or table subpartitions in a specified mode. This lock manually overrides automatic locking and permits or denies access to a table or view by other users for the duration of your operation. Some forms of locks can be placed on the same table at the same time. Other locks allow only one lock for a table. A locked table remains locked until you either commit your transaction or roll it back, either entirely or to a savepoint before you locked the table. A lock never prevents other users from querying the table. A query never places a lock on a table. Readers never block writers and writers never block readers. See Also: Oracle Database Concepts for a complete description of the interaction of lock modes COMMIT ROLLBACK SAVEPOINT Prerequisites The table or view must be in your own schema or you must have the LOCK ANY TABLE system privilege, or you must have any object privilege on the table or view. ROW SHARE ROW SHARE permits concurrent access to the locked table but prohibits users from locking the entire table for exclusive access. ROW SHARE is synonymous with SHARE UPDATE, which is included for compatibility with earlier versions of Oracle Database. ROW EXCLUSIVE ROW EXCLUSIVE is the same as ROW SHARE, but it also prohibits locking in SHARE mode. ROW EXCLUSIVE locks are automatically obtained when updating, inserting, or deleting. SHARE UPDATE See ROW SHARE. SHARE SHARE permits concurrent queries but prohibits updates to the locked table. SHARE ROW EXCLUSIVE SHARE ROW EXCLUSIVE is used to look at a whole table and to allow others to look at rows in the table but to prohibit others from locking the table in SHARE mode or from updating rows. EXCLUSIVE EXCLUSIVE permits queries on the locked table but prohibits any other activity on it. NOWAIT Specify NOWAIT if you want the database to return control to you immediately if the specified table, partition, or table subpartition is already locked by another user. In this case, the database returns a message indicating that the table, partition, or subpartition is already locked by another user. WAIT Use the WAIT clause to indicate that the LOCK TABLE statement should wait up to the specified number of seconds to acquire a DML lock. There is no limit on the value of integer. If you specify neither NOWAIT nor WAIT, then the database waits indefinitely until the table is available, locks it, and returns control to you. When the database is executing DDL statements concurrently with DML statements, a timeout or deadlock can sometimes result. The database detects such timeouts and deadlocks and returns an error.
Views: 639 OnLinE ReSoUrCe
02 Shared Lock & Exclusive Lock In oracle database table lock
 
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Purpose Use the LOCK TABLE statement to lock one or more tables, table partitions, or table subpartitions in a specified mode. This lock manually overrides automatic locking and permits or denies access to a table or view by other users for the duration of your operation. Some forms of locks can be placed on the same table at the same time. Other locks allow only one lock for a table. A locked table remains locked until you either commit your transaction or roll it back, either entirely or to a savepoint before you locked the table. A lock never prevents other users from querying the table. A query never places a lock on a table. Readers never block writers and writers never block readers. See Also: Oracle Database Concepts for a complete description of the interaction of lock modes COMMIT ROLLBACK SAVEPOINT Prerequisites The table or view must be in your own schema or you must have the LOCK ANY TABLE system privilege, or you must have any object privilege on the table or view. ROW SHARE ROW SHARE permits concurrent access to the locked table but prohibits users from locking the entire table for exclusive access. ROW SHARE is synonymous with SHARE UPDATE, which is included for compatibility with earlier versions of Oracle Database. ROW EXCLUSIVE ROW EXCLUSIVE is the same as ROW SHARE, but it also prohibits locking in SHARE mode. ROW EXCLUSIVE locks are automatically obtained when updating, inserting, or deleting. SHARE UPDATE See ROW SHARE. SHARE SHARE permits concurrent queries but prohibits updates to the locked table. SHARE ROW EXCLUSIVE SHARE ROW EXCLUSIVE is used to look at a whole table and to allow others to look at rows in the table but to prohibit others from locking the table in SHARE mode or from updating rows. EXCLUSIVE EXCLUSIVE permits queries on the locked table but prohibits any other activity on it. NOWAIT Specify NOWAIT if you want the database to return control to you immediately if the specified table, partition, or table subpartition is already locked by another user. In this case, the database returns a message indicating that the table, partition, or subpartition is already locked by another user. WAIT Use the WAIT clause to indicate that the LOCK TABLE statement should wait up to the specified number of seconds to acquire a DML lock. There is no limit on the value of integer. If you specify neither NOWAIT nor WAIT, then the database waits indefinitely until the table is available, locks it, and returns control to you. When the database is executing DDL statements concurrently with DML statements, a timeout or deadlock can sometimes result. The database detects such timeouts and deadlocks and returns an error.
Views: 742 OnLinE ReSoUrCe
Oracle DBA - Solve Long Running Query & TX Row Lock Contention | Performance Tuning
 
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How to Solve Row Lock Contention in Oracle Database - Performance Tuning - Oracle DBA Solve Row Lock Contention & Long Running Query in Oracle Database - Performance Tuning Oracle DBA - Performance Tuning Row Lock Contention Please Like, Comment, Subscribe and Share... Boxcut Media.
Views: 5028 BoxCut Media
03 Dead Lock in oracle database
 
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DML Locks DML locks or data locks guarantee the integrity of data being accessed concurrently by multiple users. DML locks help to prevent damage caused by interference from simultaneous conflicting DML or DDL operations. By default, DML statements acquire both table-level locks and row-level locks. The reference for each type of lock or lock mode is the abbreviation used in the Locks Monitor from Oracle Enterprise Manager (OEM). For example, OEM might display TM for any table lock within Oracle rather than show an indicator for the mode of table lock (RS or SRX). Row Locks (TX) Row-level locks serve a primary function to prevent multiple transactions from modifying the same row. Whenever a transaction needs to modify a row, a row lock is acquired by Oracle. There is no hard limit on the exact number of row locks held by a statement or transaction. Also, unlike other database platforms, Oracle will never escalate a lock from the row level to a coarser granular level. This row locking ability provides the DBA with the finest granular level of locking possible and, as such, provides the best possible data concurrency and performance for transactions. The mixing of multiple concurrency levels of control and row level locking means that users face contention for data only whenever the same rows are accessed at the same time. Furthermore, readers of data will never have to wait for writers of the same data rows. Writers of data are not required to wait for readers of these same data rows except in the case of when a SELECT... FOR UPDATE is used. Writers will only wait on other writers if they try to update the same rows at the same point in time. In a few special cases, readers of data may need to wait for writers of the same data. For example, concerning certain unique issues with pending transactions in distributed database environments with Oracle. Transactions will acquire exclusive row locks for individual rows that are using modified INSERT, UPDATE, and DELETE statements and also for the SELECT with the FOR UPDATE clause. Modified rows are always locked in exclusive mode with Oracle so that other transactions do not modify the row until the transaction which holds the lock issues a commit or is rolled back. In the event that the Oracle database transaction does fail to complete successfully due to an instance failure, then Oracle database block level recovery will make a row available before the entire transaction is recovered. The Oracle database provides the mechanism by which row locks acquire automatically for the DML statements mentioned above. Whenever a transaction obtains row locks for a row, it also acquires a table lock for the corresponding table. Table locks prevent conflicts with DDL operations that would cause an override of data changes in the current transaction. Table Locks (TM) What are table locks in Oracle? Table locks perform concurrency control for simultaneous DDL operations so that a table is not dropped in the middle of a DML operation, for example. When Oracle issues a DDL or DML statement on a table, a table lock is then acquired. As a rule, table locks do not affect concurrency of DML operations. Locks can be acquired at both the table and sub-partition level with partitioned tables in Oracle. A transaction acquires a table lock when a table is modified in the following DML statements: INSERT, UPDATE, DELETE, SELECT with the FOR UPDATE clause, and LOCK TABLE. These DML operations require table locks for two purposes: to reserve DML access to the table on behalf of a transaction and to prevent DDL operations that would conflict with the transaction. Any table lock prevents the acquisition of an exclusive DDL lock on the same table, and thereby prevents DDL operations that require such locks. For example, a table cannot be altered or dropped if an uncommitted transaction holds a table lock for it. A table lock can be held in any of several modes: row share (RS), row exclusive (RX), share (S), share row exclusive (SRX), and exclusive (X). The restrictiveness of a table lock's mode determines the modes in which other table locks on the same table can be obtained and held.
Views: 224 OnLinE ReSoUrCe
Understanding Locking in SQL Server - SQL Server Tutorial
 
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In this video you will understand what is locking in SQL Server? video gives brief overview Following: What is Resource types in locking of SQL Server? What is Lock Modes in SQL Server? It gives live view of looking at different type of lock modes as well as the resources types where the locks are placed. It describes in greater detail about RID, Key, Page, Extent, Table and DB Resource types in SQL Server Locking concept. It also explains Shared Locks, Update Lock, Exclusive Locks, Intent Lock, Schema Lock and Bulk Update locks in SQL Server. Blog post link for the video with script http://sqlage.blogspot.com/2015/04/understanding-locking-in-sql-server-sql.html Complete Step by Step List for DBA Tutorial Videos: http://sqlage.blogspot.com/search/label/SQL%20Sever%202014%20DBA%20Video%20Tutorial
Views: 53805 TechBrothersIT
What a database deadlock looks like
 
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Simple example of two sessions creating a deadlock in Oracle by attempting to update the same row
Views: 3302 Benjamin Drasin
Exclusive lock vs Shared Lock (Explained by Example)
 
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In this episode we discuss the differences between exclusive lock and shared lock (also known as two phase locking) with an example. We define the both and list their advantages and disadvantages. Exclusive and shared lock are very important artifacts in DBMS systems. ▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬ ⇨ [x] Proxy vs Reverse Proxy  https://goo.gl/ZYFQAi ⇨ [x] Stateful vs Stateless Applications  https://goo.gl/Fubfi6 ⇨ [x] Virtual Machines vs Containers https://goo.gl/fiECVb ⇨ [x] Database ACID - Atomicity https://goo.gl/ER9PPj ⇨ [x] Database ACID - Consistency https://goo.gl/VpLAeN ⇨ [x] Database ACID - Dirty read https://goo.gl/pkB528 ⇨ [x] Database ACID - Phantom read https://goo.gl/rnyzuA ⇨ [x] Database ACID - Non repeatable read https://goo.gl/8kgEjN ⇨ [x] Database ACID - Read uncommitted https://goo.gl/4igWUq ⇨ [x] Database ACID - Read committed https://goo.gl/twgAKL ⇨ [x] Database ACID - Repeatable read https://goo.gl/vDcP6M ⇨ [x] HOW I GREW MY YOUTUBE SUBS TO 2000 WITH A $25 MIC https://goo.gl/cM5VFx ▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
Views: 225 IGeometry
Understanding and Optimizing Oracle Latches/Mutexes - Webinar
 
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Understanding and Optimizing Oracle Latches/Mutexes. Oracle memory serialization control is core to Oracle database operations. One of the most fascinating topics in Oracle internals and performance optimization is memory serialization. We will look at the circumstances in which serialization is used, how it works, how to influence its operation, and how to diagnose problems. It's a complex situation; in order to get the upper hand on serialization control, this presentation will explore the lock (a little), the latch (a lot), and the mutex (a whole lot). Topics will include: performance diagnosis, how Oracle implements latches and mutexes, and related internal algorithms. Special attention will be given to the library cache mutex operations. This is a practical, yet deep internals presentation filled with amazing discoveries about how Oracle works. For more information go to www.orapub.com
Views: 157 OraPub, Inc.
sql lock
 
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Views: 69 man-han Tsai
Update - Locks in SQL Server - Part 4
 
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Click here to Subscribe to IT PORT Channel : https://www.youtube.com/channel/UCMjmoppveJ3mwspLKXYbVlg Update (U) locks prevent a common form of deadlock. In a repeatable read or serializable transaction, the transaction reads data, acquiring a shared (S) lock on the resource (page or row), and then modifies the data, which requires lock conversion to an exclusive (X) lock. If two transactions acquire shared-mode locks on a resource and then attempt to update data concurrently, one transaction attempts the lock conversion to an exclusive (X) lock. The shared-mode-to-exclusive lock conversion must wait because the exclusive lock for one transaction is not compatible with the shared-mode lock of the other transaction; a lock wait occurs. The second transaction attempts to acquire an exclusive (X) lock for its update. Because both transactions are converting to exclusive (X) locks, and they are each waiting for the other transaction to release its shared-mode lock, a deadlock occurs. To avoid this potential deadlock problem, update (U) locks are used. Only one transaction can obtain an update (U) lock to a resource at a time. If a transaction modifies a resource, the update (U) lock is converted to an exclusive (X) lock. Isolation Level - https://youtu.be/ESET4zuNLoM Script for Active_Locks Function --------------------------------------------------- Create Function Active_locks () returns table return select Top 10000000 case dtl.request_session_id when -2 then 'orphaned distributed transaction' when -3 then 'deferred recovery transaction' else dtl.request_session_id end as spid, db_name(dtl.resource_database_id) as databasename, so.name as lockedobjectname, dtl.resource_type as lockedresource, dtl.request_mode as locktype, es.login_name as loginname, es.host_name as hostname, case tst.is_user_transaction when 0 then 'system transaction' when 1 then 'user transaction' end as user_or_system_transaction, at.name as transactionname, dtl.request_status from sys.dm_tran_locks dtl join sys.partitions sp on sp.hobt_id = dtl.resource_associated_entity_id join sys.objects so on so.object_id = sp.object_id join sys.dm_exec_sessions es on es.session_id = dtl.request_session_id join sys.dm_tran_session_transactions tst on es.session_id = tst.session_id join sys.dm_tran_active_transactions at on tst.transaction_id = at.transaction_id join sys.dm_exec_connections ec on ec.session_id = es.session_id cross apply sys.dm_exec_sql_text(ec.most_recent_sql_handle) as st where resource_database_id = db_id() order by dtl.request_session_id
Views: 411 IT Port
How to Easily Identifying Oracle Locks
 
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How to Easily Identifying Oracle Locks. For more information, please go to: http://www.embarcadero.com/products/dbartisan-xe
Views: 2005 DBPowerStudio
Row Level Locking in Sql server
 
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Understanding Row level locking in Sql server.Please watch complete video for more detail.
Views: 918 SqlIsEasy
Transactions and Concurrency Control Patterns by Vlad Mihalcea
 
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Transactions and Concurrency Control are very of paramount importance when it comes to enterprise systems data integrity. However, this topic is very tough since you have to understand the inner workings of the database system, its concurrency control design choices (e.g. 2PL, MVCC), transaction isolation levels and locking schemes. In this presentation, I'm going to explain what data anomalies can happen depending on the transaction isolation level, with references to Oracle, SQL Server, PostgreSQL, and MySQL. I will also demonstrate that database transactions are not enough, especially for multi-request web flows. For this reason, I'm going to present multiple application-level transaction patterns based on both optimistic and pessimistic locking mechanisms.
Views: 6312 Devoxx
SQL Server  Working with Locks
 
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5. Working with Locks
Views: 16268 Eagle
14 11  Explicit Row Locking with InnoDB
 
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MYSQL 5 DEVELOPMENT
Views: 3661 Miszkoxxx
Oracle 11g Lock Monitoring with Read Committed Transaction Isolation Level Brief Explanation
 
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Oracle 11g memiliki 2 jenis transaction isolation level yaitu Read Committed dan Serializable. Secara default transaction isolation pada Oracle adalah Read Committed, yaitu ketika sebuah session melakukan Insert/Update/Delete pada sebuah data dilanjutkan dengan commit maka session lain akan secara otomatis membaca data yang sama. Terdapat Row Level Lock (TX) dan Table Level Lock (TM). Video ini memberikan contoh jelas tentang transaksi yang terjadi ketika proses locking terjadi.
Views: 162 Boby Siswanto
Lock and Unlock table statistics in Oracle Database
 
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Lock and Unlock table statistics in Oracle Database
Lesson 34 - Optimistic locking and Versioning
 
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Java Courses - Hibernate and Java Persistence API (JPA) Fundamentals __________________________________________________ Lesson 34 - Optimistic locking and Versioning __________________________________________________ » Follow me : https://www.youtube.com/channel/UCbXa80fLlQH5NeFyFkwMfOA?sub_confirmation=1
Views: 510 Java World
What is RECORD LOCKING? What does RECORD LOCKING mean? RECORD LOCKING meaning & explanation
 
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What is RECORD LOCKING? What does RECORD LOCKING mean? RECORD LOCKING meaning - RECORD LOCKING definition - RECORD LOCKING explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ Record locking is the technique of preventing simultaneous access to data in a database, to prevent inconsistent results. The classic example is demonstrated by two bank clerks attempting to update the same bank account for two different transactions. Clerks 1 and 2 both retrieve (i.e., copy) the account's record. Clerk 1 applies and saves a transaction. Clerk 2 applies a different transaction to his saved copy, and saves the result, based on the original record and his changes, overwriting the transaction entered by clerk 1. The record no longer reflects the first transaction, as if it had never taken place. A simple way to prevent this is to lock the file whenever a record is being modified by any user, so that no other user can save data. This prevents records from being overwritten incorrectly, but allows only one record to be processed at a time, locking out other users who need to edit records at the same time. To allow several users to edit a database table at the same time and also prevent inconsistencies created by unrestricted access, a single record can be locked when retrieved for editing or updating. Anyone attempting to retrieve the same record for editing is denied write access because of the lock (although, depending on the implementation, they may be able to view the record without editing it). Once the record is saved or edits are canceled, the lock is released. Records can never be saved so as to overwrite other changes, preserving data integrity. In database management theory, locking is used to implement isolation among multiple database users. This is the "I" in the acronym ACID. A thorough and authoritative description of locking was written by Jim Gray. If the bank clerks are serving two customers, but their accounts are contained in one ledger, then the entire ledger, or one or more database tables, would need to be made available for editing to the clerks in order for each to complete a transaction, one at a time (file locking). While safe, this method can cause unnecessary waiting. If the clerks can remove one page from the ledger, containing the account of the current customer (plus several other accounts), then multiple customers can be serviced concurrently, provided that each customer's account is found on a different page than the others. If two customers have accounts on the same page, then only one may be serviced at a time. This is analogous to a page level lock in a database. A higher degree of granularity is achieved if each individual account may be taken by a clerk. This would allow any customer to be serviced without waiting for another customer who is accessing a different account. This is analogous to a record level lock and is normally the highest degree of locking granularity in a database management system. In a SQL database, a record is typically called a "row." The introduction of granular (subset) locks creates the possibility for a situation called deadlock. Deadlock is possible when incremental locking (locking one entity, then locking one or more additional entities) is used. To illustrate, if two bank customers asked two clerks to obtain their account information so they could transfer some money into other accounts, the two accounts would essentially be locked. Then, if the customers told their clerks that the money was to be transferred into each other's accounts, the clerks would search for the other accounts but find them to be "in use" and wait for them to be returned. Unknowingly, the two clerks are waiting for each other, and neither of them can complete their transaction until the other gives up and returns the account. Various techniques are used to avoid such problems. Record locks need to be managed between the entities requesting the records such that no entity is given too much service via successive grants, and no other entity is effectively locked out. The entities that request a lock can be either individual applications (programs) or an entire processor. The application or system should be designed such that any lock is held for the shortest time possible. Data reading, without editing facilities, does not require a lock, and reading locked records is usually permissible.
Views: 556 The Audiopedia
Simplified DBA-019-Data Concurrency and Locks
 
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DATA CONCURRENCY More than one user connections ( session ) can access same data. For example user1 and user2 can view same employee information at the same time. But not two users can modify same data in one time. This is maintained by oracle lock mechanism. Before the database allows a session to modify data, the session must first lock the data that is being modified. A lock gives the session exclusive control over the data so that no other transaction can modify the locked data until the lock is released. Transactions can lock individual rows of data, multiple rows, or even entire tables. Oracle Database supports both manual and automatic locking. Automatically acquired locks always choose the lowest possible level of locking to minimize potential conflicts with other transactions. Demo: User1 is modifying an employee. User1 session will acquire a lock on the row. Same time user2 is trying to modify same employee. Since User1 has acquired lock, user2 has to wait until user1 releases the lock. Manual locking is possible. A user can place a lock manually as follows: LOCK TABLE mytable1 IN EXCLUSIVE MODE; With the preceding statement, any other transaction that tries to update a row in the locked table must wait until the transaction that issued the lock request completes. EXCLUSIVE is the strictest lock mode. The following are the other lock modes: ROW SHARE: Permits concurrent access to the locked table but prohibits sessions from locking the entire table for exclusive access ROW EXCLUSIVE: Is the same as ROW SHARE, but also prohibits locking in SHARE mode. The ROW EXCLUSIVE locks are automatically obtained when updating, inserting, or deleting data. ROW EXCLUSIVE locks allow multiple readers and one writer. SHARE: Permits concurrent queries but prohibits updates to the locked table. A SHARE lock is required (and automatically requested) to create an index on a table. However, online index creation requires a ROW SHARE lock that is used when building the index.
Difference between blocking and deadlocking
 
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deadlock vs blocking sql server In this video we will discuss the difference between blocking and deadlocking. This is one of the common SQL Server interview question. Let us understand the difference with an example. SQL Script to create the tables and populate them with test data Create table TableA ( Id int identity primary key, Name nvarchar(50) ) Go Insert into TableA values ('Mark') Go Create table TableB ( Id int identity primary key, Name nvarchar(50) ) Go Insert into TableB values ('Mary') Go Blocking : Occurs if a transaction tries to acquire an incompatible lock on a resource that another transaction has already locked. The blocked transaction remains blocked until the blocking transaction releases the lock. Example : Open 2 instances of SQL Server Management studio. From the first window execute Transaction 1 code and from the second window execute Transaction 2 code. Notice that Transaction 2 is blocked by Transaction 1. Transaction 2 is allowed to move forward only when Transaction 1 completes. --Transaction 1 Begin Tran Update TableA set Name='Mark Transaction 1' where Id = 1 Waitfor Delay '00:00:10' Commit Transaction --Transaction 2 Begin Tran Update TableA set Name='Mark Transaction 2' where Id = 1 Commit Transaction Deadlock : Occurs when two or more transactions have a resource locked, and each transaction requests a lock on the resource that another transaction has already locked. Neither of the transactions here can move forward, as each one is waiting for the other to release the lock. So in this case, SQL Server intervenes and ends the deadlock by cancelling one of the transactions, so the other transaction can move forward. Example : Open 2 instances of SQL Server Management studio. From the first window execute Transaction 1 code and from the second window execute Transaction 2 code. Notice that there is a deadlock between Transaction 1 and Transaction 2. -- Transaction 1 Begin Tran Update TableA Set Name = 'Mark Transaction 1' where Id = 1 -- From Transaction 2 window execute the first update statement Update TableB Set Name = 'Mary Transaction 1' where Id = 1 -- From Transaction 2 window execute the second update statement Commit Transaction -- Transaction 2 Begin Tran Update TableB Set Name = 'Mark Transaction 2' where Id = 1 -- From Transaction 1 window execute the second update statement Update TableA Set Name = 'Mary Transaction 2' where Id = 1 -- After a few seconds notice that one of the transactions complete -- successfully while the other transaction is made the deadlock victim Commit Transaction Link for all dot net and sql server video tutorial playlists https://www.youtube.com/user/kudvenkat/playlists?sort=dd&view=1 Link for slides, code samples and text version of the video http://csharp-video-tutorials.blogspot.com/2015/09/difference-between-blocking-and.html
Views: 67542 kudvenkat
SQL Server deadlock example
 
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Text version of the video http://csharp-video-tutorials.blogspot.com/2015/08/sql-server-deadlock-example.html Slides http://csharp-video-tutorials.blogspot.com/2015/08/sql-server-deadlock-example_25.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 When can a deadlock occur In a database, a deadlock occurs when two or more processes have a resource locked, and each process requests a lock on the resource that another process has already locked. Neither of the transactions here can move forward, as each one is waiting for the other to release the lock. When deadlocks occur, SQL Server will choose one of processes as the deadlock victim and rollback that process, so the other process can move forward. The transaction that is chosen as the deadlock victim will produce the following error. Msg 1205, Level 13, State 51, Line 1 Transaction (Process ID 57) was deadlocked on lock resources with another process and has been chosen as the deadlock victim. Rerun the transaction. SQL script to create the tables and populate them with test data Create table TableA ( Id int identity primary key, Name nvarchar(50) ) Go Insert into TableA values ('Mark') Go Create table TableB ( Id int identity primary key, Name nvarchar(50) ) Go Insert into TableB values ('Mary') Go The following 2 transactions will result in a dead lock. Open 2 instances of SQL Server Management studio. From the first window execute Transaction 1 code and from the second window execute Transaction 2 code. -- Transaction 1 Begin Tran Update TableA Set Name = 'Mark Transaction 1' where Id = 1 -- From Transaction 2 window execute the first update statement Update TableB Set Name = 'Mary Transaction 1' where Id = 1 -- From Transaction 2 window execute the second update statement Commit Transaction -- Transaction 2 Begin Tran Update TableB Set Name = 'Mark Transaction 2' where Id = 1 -- From Transaction 1 window execute the second update statement Update TableA Set Name = 'Mary Transaction 2' where Id = 1 -- After a few seconds notice that one of the transactions complete -- successfully while the other transaction is made the deadlock victim Commit Transaction Next Video : We will discuss the criteria SQL Server uses to choose a deadlock victim
Views: 56583 kudvenkat
Oracle Row Level Triggers follows clause Session 8
 
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Oracle SQL PLSQL and Unix Shell Scripting
Views: 336 Sridhar Raghavan
SCPT 36:What is Locking
 
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Oracle DBA Tutorials For Full Course Experience Please Go To http://mentorsnet.org/course_preview?course_id=6 Full Course Experience Includes 1. Access to course videos and exercises 2. View & manage your progress/pace 3. In-class projects and code reviews 4. Personal guidance from your Mentors
Views: 29653 Oresoft LWC
Table Locking ( MySQL ) - Tutorial
 
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Table locking is an existing query in mysql, where this query is used to lock the table at the time the user or admin wants to perform INSERT, UPDATE, or DELETE. This query is run when a database resides on the server and there are few users who can access the database.So in order to avoid conflicting data during INSERT, UPDATE, DELETE then use Table Locking. - Introduction : 0:00 - Coding : 0:52
Views: 6271 Muhammad Ikram
Oracle Tutorial||onlinetraining||pl/sql|| For Update Part-2 by Basha
 
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DURGASOFT is INDIA's No.1 Software Training Center offers online training on various technologies like JAVA, .NET , ANDROID,HADOOP,TESTING TOOLS ,ADF,INFORMATICA,TABLEAU,IPHONE,OBIEE,ANJULAR JS, SAP... courses from Hyderabad & Bangalore -India with Real Time Experts. Mail us your requirements to [email protected] so that our Supporting Team will arrange Demo Sessions. Ph:Call +91-8885252627,+91-7207212428,+91-7207212427,+91-8096969696. http://durgasoft.com http://durgasoftonlinetraining.com https://www.facebook.com/durgasoftware http://durgajobs.com https://www.facebook.com/durgajobsinfo......
Update and Transactions: Databases for Developers #8
 
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In this episode Chris discusses the ins and outs of using updates to change data in existing rows. Watch this to learn how to write update statements and avoid the dangers of deadlock and lost updates. Oracle Database SQL Language reference for update: http://docs.oracle.com/database/122/SQLRF/UPDATE.htm#SQLRF01708 Take the Databases for Developers FREE SQL course at https://devgym.oracle.com/devgym/database-for-developers.html Need help with SQL? Ask us over on AskTOM: https://asktom.oracle.com Twitter: https://twitter.com/ChrisRSaxon Daily SQL Twitter tips: https://twitter.com/SQLDaily All Things SQL blog: https://blogs.oracle.com/sql/ ============================ The Magic of SQL with Chris Saxon Copyright © 2017 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: 3549 The Magic of SQL
Concurrency Control - Lock Based Protocol in DBMS Transaction Management
 
11:48
DBMS Tutorial in English, Hindi - Concurrency Control - Lock Based Protocol in DBMS Transaction Management for students of IP University Delhi and Other Universities, Engineering, MCA, BCA, B.Sc, M.Sc Colleges.
Views: 162609 Easy Engineering Classes
Hints and Tips - Avoiding never ending locks - part 1
 
05:52
Row locking is a critical component of ensuring the integrity of your data inside the database. But locks of extended duration can easily create system-wide problems in your applications. This quick tip gives you some ideas for handling locks better. ====================================================== 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: 1056 Connor McDonald
Updating Oracle Management Agents Using Agent Gold Images
 
06:12
Enterprise Manager enables you to mass-update Management Agents using Agent Gold Images. An Agent Gold Image represents the ideal state of a Management Agent in a data center, having customized configurations of the desired versions of the Management Agent software, the desired versions of the monitoring plug-ins, and the desired patches. ================================= For more information, see http://www.oracle.com/goto/oll 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.
Rollback,Savepoint,Commit,Transaction IN ORACLE PART1
 
06:29
PART1 1-ROLLBACK 2-SAVE POINT 3-ROLLBACK TO AN SAVE POINT 4-COMMIT 5-SET TRANSACTION PART2 6-GRANT 7-DEADLOCK .....BY YASSIR TAQATQA بواسطة ياسر طقاطقة
Views: 3372 Yassir Taqatqa
Sql server 2016 Tutorial-Locks, blocking, and deadlocks-part 13
 
03:10
Sql server 2016 Tutorial-Locks, blocking, and deadlocks-part 13
Views: 2121 kumaran kumaran
Lock Compatibility in SQL Server
 
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Click here to Subscribe to IT PORT Channel : https://www.youtube.com/channel/UCMjmoppveJ3mwspLKXYbVlg Lock compatibility controls whether multiple transactions can acquire locks on the same resource at the same time. If a resource is already locked by another transaction, a new lock request can be granted only if the mode of the requested lock is compatible with the mode of the existing lock. If the mode of the requested lock is not compatible with the existing lock, the transaction requesting the new lock waits for the existing lock to be released or for the lock timeout interval to expire.For example, no lock modes are compatible with exclusive locks. While an exclusive (X) lock is held, no other transaction can acquire a lock of any kind (shared, update, or exclusive) on that resource until the exclusive (X) lock is released. Alternatively, if a shared (S) lock has been applied to a resource, other transactions can also acquire a shared lock or an update (U) lock on that item even if the first transaction has not completed. However, other transactions cannot acquire an exclusive lock until the shared lock has been released.
Views: 296 IT Port
MySQL Chapter 17 - Locks
 
03:37
Views: 2343 Suresh Kumar
Bulk Update - Locks in SQL Server - Part 9 Tamil
 
06:50
Click here to Subscribe to IT PORT Channel : https://www.youtube.com/channel/UCMjmoppveJ3mwspLKXYbVlg The Database Engine uses bulk update (BU) locks when bulk copying data into a table, and either the TABLOCK hint is specified or the table lock on bulk load table option is set using sp_tableoption. Bulk update (BU) locks allow multiple threads to bulk load data concurrently into the same table while preventing other processes that are not bulk loading data from accessing the table. Explained in Tamil
Views: 114 IT Port
SQL Server Exploring Locks
 
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4. Exploring Locks
Views: 16612 Eagle
PL/SQL: Cursors using FOR loop
 
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In this tutorial, you'll learn h.ow to write a cursor using for loop and the advantage of it. 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: 17084 radhikaravikumar
Oracle User account is Locked/Expired & Backup of user account password
 
15:00
This video will cover the trobleshooting steps for follwoing three topics 1) User account in Locked 2) User account is Locked and expired 3) Backup of user account/Reset password
Views: 382 ANKUSH THAVALI
Hibernate Tip: How to use a timestamp for versioning and optimistic locking
 
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Get more recipes like this one in my new book Hibernate Tips: More than 70 solutions to common Hibernate problems: https://goo.gl/XfywNk When you had to map a legacy table model in one of your projects, you probably know this situation. Instead of a numeric version column, the table model uses the timestamp of the last update. I don’t recommend using this approach because numeric versioning is much more efficient. But if you have to, you can also use a timestamp for versioning with JPA and Hibernate. If you like this video, please give me your thumbs up and share it with your friends and co-workers. Like my channel? Subscribe! ➜ http://bit.ly/2cUsid8 Join the free Member Library: https://goo.gl/dtyIIC Read the accompanying post: https://www.thoughts-on-java.org/hibernate-tips-use-timestamp-versioning-optimistic-locking/ Want to connect with me? Blog: http://www.thoughts-on-java.org/ Twitter: https://twitter.com/thjanssen123 Facebook: https://www.facebook.com/thoughtsonjava
Views: 1394 Thoughts On Java
Phantom Read Problem | problems in concurrent execution of transactions | DBMS
 
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This video contains the basic concepts of Transaction and tell what Phantom read problem in breif and will help students in various competitive exams like GATE , NET, PSU'S etc Following are the important topics of dbms ER‐model - entity–relationship model, strong entity set, weak entity set, single valued attribute, multivalued attribute, stored attribute, derived attribute, simple attribute composite attribute, weak relationship, strong relationship, mapping, cardinality ratios, discriminator attribute, fan trap, chasm trap Relational model – relational table, column, domain, row, tuple, relational algebra – selection, projection, union, intersection, set difference, Cartesian product, natural join, left outer join, right outer join, complete outer join, theta join, division operator, nested query, safe query tuple calculus – tuple relational calculus, domain relational calculus, SQL – select, from, where, order by, group by, max, min, avg, count, sum, having, Integrity constraints – super key, candidate key, primary key, foreign key, alternate key, secondary key, surrogate key normal forms – first normal form, second normal form, third normal form, bcnf, 4nf, 5nf, functional dependency, minimal cover, canonical collection, multivalued functional dependency, dependency preserving, lossy and lossless decomposition. File organization – indexing, B, B+ trees, key attribute, anchor attribute, primary indexing, secondary indexing, clustered indexing, multilevel indexing, block pointer, tree pointer, record pointer, top down search, sequential search, range query, index file, ordering, non-ordering Transactions and concurrency control- transaction, acid properties, atomicity, consistency, isolation, durability, life cycle of a transaction, active state, partially committed state, committed state, abort, rollback, terminated, phantom read, dirty read, unrepeatable read, lost update problem, conflict serializability, view serializability, irrecoverable schedule, cascading rollback, recoverable schedule, cascadless schedule. Lock based protocol, two phase locking, exclusive lock, shared lock, growing phase, shrinking phase, conservative two-phase locking, rigorous two phase locking, strict two phase locking, time stamping, time stamp, read, write, deadlock, granularity, tree based protocol, phantom read problem,phantom read,phantom read problem in dbms,phantom read problem in transaction,phantom read in sql,phantom reads example in sql server,phantom read and dirty read,phantom read and non repeatable read,dirty read vs non repeatable read vs phantom read,problems with concurrent execution of transactions,unrepeatable read problem in dbms,phantom read problem in dbms,lost update problem in dbms,blind write in dbms phantom read problem,phantom read,phantom read problem in dbms,phantom read problem in transaction,phantom read in sql,phantom reads example in sql server,phantom read and dirty read,phantom read and non repeatable read,dirty read vs non repeatable read vs phantom read,problems with concurrent execution of transactions,unrepeatable read problem in dbms,phantom read problem in dbms,lost update problem in dbms,blind write in dbms
Views: 50732 KNOWLEDGE GATE
Intent - Locks in SQL Server - Part 6
 
06:10
Click here to Subscribe to IT PORT Channel : https://www.youtube.com/channel/UCMjmoppveJ3mwspLKXYbVlg The Database Engine uses intent locks to protect placing a shared (S) lock or exclusive (X) lock on a resource lower in the lock hierarchy. Intent locks are named intent locks because they are acquired before a lock at the lower level, and therefore signal intent to place locks at a lower level. Intent locks serve two purposes: --------------------------------------------------- a) To prevent other transactions from modifying the higher-level resource in a way that would invalidate the lock at the lower level. b) To improve the efficiency of the Database Engine in detecting lock conflicts at the higher level of granularity. if a transaction has an exclusive lock on a row, SQL Server places an intent lock on the table. When another transaction requests a lock on a row in the table, SQL Server knows to check the rows to see if they have locks. If a table does not have intent lock, it can issue the requested lock without checking each row for a lock Isolation Level - https://youtu.be/ESET4zuNLoM Script for Active_Locks Function --------------------------------------------------- Create Function Active_locks () returns table return select Top 10000000 case dtl.request_session_id when -2 then 'orphaned distributed transaction' when -3 then 'deferred recovery transaction' else dtl.request_session_id end as spid, db_name(dtl.resource_database_id) as databasename, so.name as lockedobjectname, dtl.resource_type as lockedresource, dtl.request_mode as locktype, es.login_name as loginname, es.host_name as hostname, case tst.is_user_transaction when 0 then 'system transaction' when 1 then 'user transaction' end as user_or_system_transaction, at.name as transactionname, dtl.request_status from sys.dm_tran_locks dtl join sys.partitions sp on sp.hobt_id = dtl.resource_associated_entity_id join sys.objects so on so.object_id = sp.object_id join sys.dm_exec_sessions es on es.session_id = dtl.request_session_id join sys.dm_tran_session_transactions tst on es.session_id = tst.session_id join sys.dm_tran_active_transactions at on tst.transaction_id = at.transaction_id join sys.dm_exec_connections ec on ec.session_id = es.session_id cross apply sys.dm_exec_sql_text(ec.most_recent_sql_handle) as st where resource_database_id = db_id() order by dtl.request_session_id
Views: 590 IT Port
Foam Rollers on Locks vs. Lock Loops and Pipe Cleaners| Bouncy Consistent Curls for Sisterlocks
 
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Please see my other videos on using lock loops and pipe cleaners. The foam rollers or sponge rollers on sisterlocks is an entirely different look with lots of bounce. So easy to place in hair. Check out the other videos on lock loops, pipe cleaners and the first part of this video to see how I installed these sponge rollers on my sisterlocks! ___________________________________If you find the message, its for you, so tune in and be willing to dive deep into how this applies to you. Watch as Tunisia Ali, gives it to you in a way you can understand. For energy exchange donations to the channel: PayPal.me/TunisiaAli Cash APP: cash.me/$TunisiaAli218 I conduct distance healing sessions and chakra balancing, along with a varied range of other health and healing services designed for your spiritual wellness and enlightenment. Set up your distance energy healing session by going to: https://www.hidayahreiki.com/book-online As a certified coach, I also provide coaching for those spirits seeking to connect with the vision of who they truly are. I specialize in prosperity consciousness, wealth creation, relationships, and entrepreneurship. To sign up for a free discovery session go to: https://butterflytransformations.com ______________________________________________ I conduct individual and group intuitive soul readings (tarot and oracle) of various configurations and pricing. For video link readings, please allow 2 days for processing. It is usually less. If you want expedited processing, within 2 hours, please add the “expedite fee” of $30.00 for your special reading to the regular price. VISIT MY WEBSITE TO BOOK A PERSONAL SKYPE OR PHONE CALL OR Video Link READING! If you aren’t technology equipped and prefer an email reading, I can do this as well. I do not center readings around health or legal issues. If this comes up, I will shine the light of awareness on them, however. Also, I prefer you send your first and last name and a photo for these readings. I like to really feel into the spirit of who you are. You can do this in the easiest way possible, if at all. For booking a reading of any type go to: https://www.hidayahreiki.com/book-online ONLINE PRICING ONLY ( After ‘subscribership’) 15 minute video reading is $22.22 25 minute video reading is $ 33.33 40 minute paired reading (Friends or lovers): $55.55 Phone call reading: 10 minutes - $11.11 Phone call reading: 25 minutes-$22.22 Phone call reading (2) 40 minutes-$44.44 When sending in payment, please attach an email or write in the ‘notes’ space with your payment what the situation/ event/ or love connection concerns very briefly. Send email to: [email protected] Atlanta F2F readings: $50.00 for 2 readings or with one with 3 decks. Online pricing only, mention the channel. ________________________________________ For certified Life Coaching go to: https://butterflytransformations.com For online classes for self development and connecting with the vision of who you really are visit my Powerdigm Academy: http://butterfly-transformations.teachable.com For my youtube channel to raise consciousness and get you out of your cocoon and into your wings, go to: https://www.youtube.com/channel/UCUQgm2DpCj53iLSuPaNnQYg To connect with me on Facebook: facebook.com/butterflytransformations.com
Views: 524 Tunisia Ali
This Week in Development: Apple, HTC, Google, Oracle, Motorola and Samsung
 
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This week on the XDA News Portal, we saw many important stories. To give a run down of these stories, XDA TV Producer Jordan returns with another episode of This Week in Development. Jordan mentions the Apple versus HTC patent wars and court battles. In more big, rich companies versus other rich companies news, Jordan updates us on the Oracle versus Google trial. In more Google news, the limit on device deauthorization on Google Music is discussed. The lamentable actions by Motorola and the locking down of their devices is mentioned. Finally, Jordan urges you to go check out XDA Elite Recognized Developer AdamOutler's Galaxy Nexus tear down and unboxing. XDA Portal: http://www.xda-developers.com XDA Forums: http://forum.xda-developers.com XDA TV: http://www.xda-developers.com/xda-tv/ Links to all stories mentioned: So It Begins -- Apple's Victory Affecting HTC's US Imports: http://www.xda-developers.com/android/so-it-begins-apples-victory-affecting-htcs-us-imports/ Update on the Oracle Versus Google Trial: http://www.xda-developers.com/android/update-on-the-oracle-versus-google-trial/ Google Music Limits Device Deauthorization, Makes Flashers Pay: http://www.xda-developers.com/android/google-music-limits-device-deauthorization-makes-flashers-pay/ Motorola at it Again, Locks Down Atrix 4G Even More: http://www.xda-developers.com/android/motorola-at-it-again-locks-down-atrix-4g-even-more/ Photon 4G to be Locked Down Like Atrix 4G Next Update: http://www.xda-developers.com/android/photon-4g-to-be-locked-down-like-atrix-4g-next-update/ First Custom ROM Appears for the Nokia Lumia 710: http://www.xda-developers.com/windows_phone/first-custom-rom-appears-for-the-nokia-lumia-710/ Galaxy Nexus Unboxed the XDA Way -- XDA TV: http://www.xda-developers.com/android/galaxy-nexus-unboxed-the-xda-way-xda-tv/ Link to Jordan's Channel: http://youtube.com/thisweekinlinux Make sure to check out the Samsung Smart App Challenge 2012! http://developer.samsung.com/
Views: 6835 xdadevelopers

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