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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. #RowLevelLock Oracle database Unbeatable,Unbreakable Platform..
Views: 7765 Oracle World
Locking in Oracle | Oracle SQL Tutorial Videos | Mr.Vijay Kumar
 
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Locking in Oracle | Oracle SQL Tutorial Videos | Mr.Vijay Kumar ** For Online Training Registration: https://goo.gl/r6kJbB ► Call: +91-8179191999 💡 Visit Our Website for Classroom Training: https://nareshit.in/oracle-training/ 💡 For Online Training: https://nareshit.com/oracle-online-training/ #Oracle #Training #CourseVideos -------------------------- 💡 About NareshIT: "Naresh IT is having 14+ years of experience in software training industry and the best Software Training Institute for online training, classroom training, weekend training, corporate training of Hadoop, Salesforce, AWS, DevOps, Spark, Data Science, Python, Tableau, RPA , Java, C#.NET, ASP.NET, Oracle, Testing Tools, Silver light, Linq, SQL Server, Selenium, Android, iPhone, C Language, C++, PHP and Digital Marketing in USA, Hyderabad, Chennai and Vijayawada, Bangalore India which provides online training across all the locations -------------------------- 💡 Our Online Training Features: 🎈 Training with Real-Time Experts 🎈 Industry Specific Scenario’s 🎈 Flexible Timings 🎈 Soft Copy of Material 🎈 Share Videos of each and every session. -------------------------- 💡 Please write back to us at 📧 [email protected]/ 📧 [email protected] or Call us at the USA: ☎+1404-232-9879 or India: ☎ +918179191999 -------------------------- 💡 Check The Below Links ► For Course Reg: https://goo.gl/r6kJbB ► Subscribe to Our Channel: https://goo.gl/q9ozyG ► Circle us on G+: https://plus.google.com/+NareshIT ► Like us on Facebook: https://www.facebook.com/NareshIT ► Follow us on Twitter: https://twitter.com/nareshitek ► Follow us on Linkedin: https://goo.gl/CRBZ5F ► Follow us on Instagram: https://goo.gl/3UXYK3
Views: 25191 Naresh i Technologies
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: 974 Md Arshad
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: 286 Md Arshad
Oracle Locks and Lock Trees
 
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Rows Locks and sessions waiting in a "tree order" on Row Locks in Oracle
Views: 259 Hemant K Chitale
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: 1026 Md Arshad
How to Create ROW LEVEL LOCK  1 Of 2
 
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Hi... Friend In this video we learn how to create ROW LEVEL LOCKING IN ORACLE DATABASE 11g
Views: 78 PGT POINT
Oracle Big Data SQL: 5 - Apply Row-Level Security
 
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This video shows you how to apply row-level security to your big data sources using Oracle Big Data SQL. ================================= To improve the video quality, click the gear icon and set the Quality to 1080p/720p HD. For more information, see http://www.oracle.com/goto/oll and http://docs.oracle.com Copyright © 2018 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.
Hints and Tips - Avoiding never ending locks - part 1
 
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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: 1335 Connor McDonald
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: 80316 kudvenkat
Table Shrinking in Oracle Database
 
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1.Shrink the Table: Shrinking is started from 10g. In this method I’m using user u1 and table name sm1. Now I’m deleting some rows in sm1 COUNT ---------- 1048576 Table sm1 has 1048576 rows. [email protected]: delete from sm1 where deptno=10; 262144 rows deleted. I deleted above number of rows. Rows COUNT ---------- 786432 And I’m giving commit [email protected]: commit; Commit complete. So now we have 786432 rows in sm1 table. Now see the following command [email protected]: select OWNER,TABLESPACE_NAME,SEGMENT_NAME,SEGMENT_TYPE,BYTES/1024/1024||' mb'"space",BLOCKS,EXTENTS from dba_segments where tablespace_name like 'U%TS'; OWNER TABLESPACE_NAME SEGMENT_NAME SEGMENT_TYPE space BLOCKS EXTENTS ----- --------------- ------------- ------------- ------ ---------- ---------- U1 U1TS SM1 TABLE 29 mb 3712 44 After I deleted some rows in sm1 table still above result showing same values, so now our duty is shrink this table. This is done by following 2 ways, i By using COMPACT key word: In this method shrinking is done in two phases. In the first phase all fragmented space are just defragmented, but still the High Water Mark is persist with last used block only. That mean used free blocks are not de allocated and HWM is not updated here. Issue the following command before use shrink command. [email protected] alter table sm1 enable row movement; Table altered. There is particular use with above command, when we shrink the table all rows are moves to contiguous blocks, so here row movement should be done. By default the row movement is disabled for any table, so above command enabled the row movement. Then execute shrink command now. [email protected]: alter table sm1 shrink space compact; Table altered. Now see the space of table by using below command. [email protected]: select OWNER,TABLESPACE_NAME,SEGMENT_NAME,SEGMENT_TYPE,BYTES/1024/1024||' mb'"space",BLOCKS,EXTENTS from dba_segments where tablespace_name like 'U%TS'; OWNER TABLESPACE_NAME SEGMENT_NAME SEGMENT_TYPE space BLOCKS EXTENTS ----- --------------- ------------- ------------- ------ ---------- ---------- U1 U1TS SM1 TABLE 29 mb 3712 44 So here seems nothing happened with above shrink command, but internally the fragmented space is defragmented. But the high water mark is not updated, used free blocks are also not de allocated. For de allocating the used blocks we have to execute below command. This is the second phase. [email protected]: alter table sm1 shrink space; Table altered. Now see the space by using below command. [email protected]: select OWNER,TABLESPACE_NAME,SEGMENT_NAME,SEGMENT_TYPE,BYTES/1024/1024||' mb'"space",BLOCKS,EXTENTS from dba_segments where tablespace_name like 'U%TS'; OWNER TABLESPACE_NAME SEGMENT_NAME SEGMENT_TYPE space BLOCKS EXTENTS ----- --------------- ------------- ------------- ---------- ---------- ---------- U1 U1TS SM1 TABLE 20.8125 mb 2664 36 So now the space of sm1 table is reduced. Note: Actually the alter table sm1 shrink space command will complete these two phases of the shrinking of table at a time. But here we done shrink process in two phases because when we use alter table sm1 shrink space command the table locked temporarily some time period, during this period users unable to access the table. So if we use alter table sm1 shrink space compact command the table is not locked but space is defragmented. When we not in business hours issue the second phase shrink command then users are won’t get any problem. ii Because of above method the table dependent objects are goes to invalid state, to overcome this problem we have to use below command. [email protected]: alter table sm1 shrink space cascade; Table altered. The above command also shrinks the space of all dependent objects. We also do this in two phases like above two phases. See the below command. [email protected]: alter table sm1 shrink space compact cascade; Table altered. And then [email protected]: alter table sm1 shrink space cascade; Table altered. Transporting tablespace to different platform by Using RMAN : https://www.youtube.com/watch?v=CN401PUKK4A Oracle EBS apps Upgrade from 12 2 to 12 2 5 (start CD 51) : https://www.youtube.com/watch?v=zeO4goqR70Y Transport tablespace by using RMAN.: https://www.youtube.com/watch?v=YG6kWX7Par8
Views: 7549 BhagyaRaj Katta
SQL Execution/Elapsed Time - DBPerf Video 11
 
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In this video you will undestand what is SQL Execution time. You will get to know about CPU time and Wait Time . Our Upcoming Online Course Schedule is available in the url below https://docs.google.com/spreadsheets/d/1qKpKf32Zn_SSvbeDblv2UCjvtHIS1ad2_VXHh2m08yY/edit#gid=0 Reach us at [email protected]
Views: 2615 Ramkumar Swaminathan
Hints and Tips - Avoiding never ending locks - part 2
 
03:57
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: 828 Connor McDonald
Using DBMS_XPLAN.DISPLAY_CURSOR to examine execution plans
 
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In this video I describe how you can use Oracle's DBMS_XPLAN.DISPLAY_CURSOR to examine the execution plan for a SQL statement that has recently been executed and determine if that plan is optimal or not and where you might be able to optimize it.
Views: 11654 Maria Colgan
AWR Reports and Baselines
 
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AWR Reports and Baselines watch more videos at https://www.tutorialspoint.com/videotutorials/index.htm Lecture By: Mr. Parth Panjab, Tutorials Point India Private Limited
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.
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: 1592 SqlIsEasy
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: 7780 Muhammad Ikram
Time-Lock Puzzles in the Random Oracle Model
 
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Mohammad Mahmoody, Tal Moran, and Salil Vadhan. Crypto 2011, August 15, 2011. Mohammad Mahmoody, Tal Moran, and Salil Vadhan Cornell University, Harvard University, and Harvard University Abstract. A time-lock puzzle is a mechanism for sending messages "to the future". The sender publishes a puzzle whose solution is the message to be sent, thus hiding it until enough time has elapsed for the puzzle to be solved. For timelock puzzles to be useful, generating a puzzle should take less time than solving it. Since adversaries may have access to many more computers than honest solvers, massively parallel solvers should not be able to produce a solution much faster than serial ones. To date, we know of only one mechanism that is believed to satisfy these properties: the one proposed by Rivest, Shamir and Wagner (1996), who originally introduced the notion of time-lock puzzles. Their puzzle is based on the serial nature of exponentiation and the hardness of factoring, and is therefore vulnerable to advances in factoring techniques (as well as to quantum attacks). In this work, we study the possibility of constructing time-lock puzzles in the random-oracle model. Our main result is negative, ruling out time-lock puzzles that require more parallel time to solve than the total work required to generate a puzzle. In particular, this should rule out black-box constructions of such timelock puzzles from one-way permutations and collision-resistant hash-functions. On the positive side, we construct a time-lock puzzle with a linear gap in parallel time: a new puzzle can be generated with one round of n parallel queries to the random oracle, but n rounds of serial queries are required to solve it (even for massively parallel adversaries).
Views: 612 TheIACR
What is DB Time - DBPerf Video 12
 
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In this video you will understand what is DB TIme in an Oracle Database. . Our Upcoming Online Course Schedule is available in the url below https://docs.google.com/spreadsheets/d/1qKpKf32Zn_SSvbeDblv2UCjvtHIS1ad2_VXHh2m08yY/edit#gid=0 Reach us at [email protected]
Views: 2757 Ramkumar Swaminathan
7.ORACLE WORLD- FLASHBACK TRANSACTION QUERY
 
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Hi guys today we will learn how to perform flashback transaction query to find out the DDL that performed by users. #FLASHBACKTRANSACTIONQUERY Oracle database Unbeatable,Unbreakable Platform..
Views: 1655 Oracle World
Understanding And Resolving Oracle CBC Wait/Latch Contention - Introduction
 
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Understanding And Resolving Oracle CBC Wait/Latch Contention When a server process needs to access a buffer it must access the cache buffer chain (CBC) structure to determine if the buffer is already in the buffer cache. With just the right workload mix, performance can be a problem. Learning about the relevant Oracle internals and how to diagnose and solve CBC performance problems is what this seminar is all about. For more information go to www.orapub.com
Views: 1163 OraPub, Inc.
Why is my Oracle Database Slow? The SQL Developer Performance Dashboard
 
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Oracle SQL Developer's product manager, Jeff Smith, takes you through the Instance Viewer: a performance dashboard for your Oracle Database. See expensive queries, wait event break downs, and more!
Views: 2446 Jeff Smith
MySQL Chapter 17 - Locks
 
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Views: 2840 Suresh Kumar
Lock Escalation in SQL Server
 
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Click here to Subscribe to IT PORT Channel : https://www.youtube.com/channel/UCMjmoppveJ3mwspLKXYbVlg Lock Escalation is the Converting Process of Many fine-grain locks (Row Level) into fewer coarse-grain locks (Table Level, Page Level), reducing system overhead while increasing the probability of Concurrency contention Every lock needs some bytes of Memory. When SQL is going to change a lot of rows, Engine will acquire lot of Row level locks and it takes huge memory for it and having multiple queries locking different parts of the table creates the possibility for deadlock if one process is waiting on another. To avoid this SQL Server implements Lock Escalation
Views: 1109 IT Port
Multiple Rows in Single Insert Statement Tamil
 
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Click here to Subscribe to IT PORT Channel : https://www.youtube.com/channel/UCMjmoppveJ3mwspLKXYbVlg How to Insert multiple records into a Table
Views: 269 IT Port
how to unlock oracle user account? ORA-28000: the account is locked
 
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This video demonstrates how to solve the ORA-28000: the account is locked error. When we try to connect to a schema that has been locked by the DBA or by wrong password attempts than the error ORA:28000 is encountered. This video will demonstrate the ways in which the error can be resolved. To get the queries shown in the video, you can visit our website http://oracleplsqlblog.com/FullBlog/FullBlog/23
Views: 7857 Kishan Mashru
Oracle Performance Tuning Interview Questions For Developers
 
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For more Questions check http://www.dbvidya.com/oracle-performance-tuning-interview-questions-developers-dbas/ [email protected] +91 991 2323 000 Oracle SQL Tuning Video Tutorial https://dbvidya.talentlms.com/catalog/info/id:125 Oracle DBA Performance Tuning https://dbvidya.talentlms.com/catalog/info/id:128 Dimensional Modeling Video Tutorial https://dbvidya.talentlms.com/catalog/info/id:131 Erwin Tool Training Video Tutorial https://dbvidya.talentlms.com/catalog/info/id:130 Oracle Performance Tuning Online Training : http://www.dbvidya.com/course/performance-tuning-for-dba/ Oracle SQL Performance Tuning Training Online : http://www.dbvidya.com/course/sql-tuning-advanced/ Oracle Performance Tuning Videos Tutorial for DBA and Developers : http://www.dbvidya.com/oracle-performance-tuning-videos/ Oracle AWR Tutorial: http://www.dbvidya.com/course/oracle-awr/ Erwin Tool Online Training : http://www.dbvidya.com/course/erwin-tool/ ER Data Modeling Course : http://www.dbvidya.com/course/er-modeling/ Dimensional Modeling Training Online : http://www.dbvidya.com/course/dimensional-modeling/ Oracle Database Blogs : http://www.dbvidya.com/blog/
Views: 880 DbVidya
3.ORACLE WORLD - Flashback Table Point in time Recovery in oracle
 
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Hello friends in this demo we learn about how to perform a flashback point in time recovery on table in Oracle database,one important thing is that flashback not supported on SYS user objects... #performingflashback #FlashbackTablePointintimeRecovery By Lalit Saini
Views: 3522 Oracle World
Change INITRANS on table in Oracle database
 
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http://dbacatalog.blogspot.com
Views: 906 dbacatalog
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: 18684 radhikaravikumar
How to Perform Horizontal Fragmentation In Oracle Database
 
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Hii there from Codegency! We are a team of young software developers and IT geeks who are always looking for challenges and ready to solve them, Feel free to contact us.. Do visit my instagram page and also like us on facebook, stay connected :) Instagram: https://www.instagram.com/code_gency/ Facebook: https://www.facebook.com/cgency/ Twitter : https://www.twitter.com/codegency Contact: +919769620035, +918108849398 For Blackbook Writeups & Descriptions: https://codegency.blogspot.in For Latest Notes & References: https://sites.google.com/view/itscholar/home
Views: 804 Codegency
Why Isn't My Query Using an Index?
 
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“Why isn’t my query using an index?” is a common question people have when tuning SQL. This session explores the factors that influence the optimizer’s decision to answer this question. It does so by comparing fetching rows from a database table to finding all the red M&Ms a packet, and contrasts using an index range scan and a full table scan. It also introduces the concepts of blocks and the clustering factor. The session offers a discussion of how these affect the optimizer's calculations, and includes a demo of how these concepts work in practice using real SQL queries. This session is intended for developers who want to learn the basics of how the optimizer chooses between an index range or full table scan. Speaker: Chris Saxon
Views: 318 Oracle Developers
Pivot Table and its advanced properties in OBIEE 11g and 12C
 
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This video shows you advanced properties of pivot table in obiee 11g and obiee 12c
Slow SQL Query? Get the Plan in Oracle SQL Developer!
 
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See how to get execution and explain plans, format and views those plans, use AutoTrace, and Real Time SQL Monitoring for your SQL queries in Oracle SQL Developer.
Views: 4388 Jeff Smith
Delete vs Truncate   similarities and differences in SQL Server
 
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Tried to explain the difference between Truncate and Delete. Give an idea about 8KB pages in SQL. TRUNCATE • We cannot use the where clause with TRUNCATE, it removes all rows from a table. • TRUNCATE is executed using a table lock and the whole table is locked to remove all records. • It’s faster as compare to delete command because of no logging in the transaction log • Identify the column is reset to its seed value if the table contains an identity column. • Truncate cannot be used with indexed views. • TRUNCATE TABLE removes the data by deallocating the data pages used to store the table data and records only the page de-allocations in the transaction log. • Truncate uses the less transaction space than Delete statement. DELETE • DELETE is executed using a row lock; each row in the table is locked for deletion. • We can use where clause with DELETE to filter & delete specific records. • The DELETE command is used to remove rows from a table based on WHERE condition. • It maintains the log, so it slower than TRUNCATE. • The DELETE statement removes rows one at a time and records an entry in the transaction log for each deleted row. • The identity of the column keep DELETE retains the identity. • To use Delete you need DELETE permission on the table. • Delete uses the more transaction space than Truncate statement. • Delete can be used with indexed views.
What exactly is PLAN TABLE in Oracle Database #Performance #Tuning
 
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Running an EXPLAIN PLAN to generate EXECUTION PLAN in oracle database is possible with PLAN_TABLE. But this video will give you much more insights of what is this PLAN_TABLE. Learn how is PLAN_TABLE called as global temporary table. Need Oracle database training? WhatsApp to +919951696808 visit www.orskl.com/training
Views: 3256 OrSkl Academy
Select and Insert query in SQL | Part 4 | SQL tutorial for beginners | Tech Talk Tricks
 
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Welcome to tech talk tricks and in this video, we will learn about select and insert statement.So stay tuned and watch select and insert query in sql. #TechTalkTricks #RanaSingh The SELECT statement is used to select data from a database. The data returned is stored in a result table, called the result-set. SELECT Syntax: SELECT column1, column2, ...FROM table_name; Here, column1, column2, ... are the field names of the table you want to select data from. If you want to select all the fields available in the table, use the following syntax: SELECT * FROM table_name; At tech talk trick channel you will learn all kind of technology like language,tutorials and amazing computer tips and tricks. insert into table from another table sql server insert into values select sql insert into values insert into sql multiple rows insert into select oracle insert into select mysql insert into table from another table oracle select into sql server ************************************************** Follow Tech Talk Trick on Facebook https://www.facebook.com/techtalktricks ************************************************** Follow tech talk trick on Twitter https://twitter.com/tecktalktrick ************************************************** Follow Tech Talk Tricks on Instagram https://www.instagram.com/techtalktricks ************************************************** Subscribe tech talk tricks on YouTube https://www.youtube.com/techtalktricks *************************************************** 1.How to make your computer start up & shutdown faster https://www.youtube.com/watch?v=3kSjizTn7MM 2.How To Trace Name/Address/Location Of UnKnown Number Easily https://www.youtube.com/watch?v=kyYfOP66l1Y 3.How to make web page print-friendly https://www.youtube.com/watch?v=YPR7JHA0Apk 4.How to Lock Folder Without any software https://www.youtube.com/watch?v=BhEduEM9pws 5.How to enable undo in Gmail https://www.youtube.com/watch?v=g1fOwTQ3zJg 6.How To Recover All Deleted, Formatted, Damaged Files https://www.youtube.com/watch?v=fl3DX6RBoqo 7.How to make Bootable USB pen drive for Windows https://www.youtube.com/watch?v=IXJE859pxWg 8.How to Unlock Android Pattern or Pin Lock without losing data https://www.youtube.com/watch?v=yN4JnAo7SvU 9.how to track a cell phone location for free https://www.youtube.com/watch?v=0kCLyPJ8cM0 10.How to fix or repair pen drive using cmd https://www.youtube.com/watch?v=ny4VhM2TsWM 11.how to get wifi password of neighbor https://www.youtube.com/watch?v=LCFn6IjvnMM 12.How to Send an Email In Future https://www.youtube.com/watch?v=oo84GRHe5Vg 13.How To Setup Wifi Hotspot Without Any Software in Windows 10 https://www.youtube.com/watch?v=6Bzyvs44G50 14.how to download YouTube video without any software https://www.youtube.com/watch?v=RDfDGY3Be9Y 15.HOW TO SET SHUTDOWN TIMER IN WINDOWS OS (HINDI) https://www.youtube.com/watch?v=Vb5Ou7sc4uk 16.How To Convert Word File (Any File Format) to PDF file (Any File Format) https://www.youtube.com/watch?v=Nd0YtV9MwqQ 17.How To Hide Drive of Computer Using Command Prompt (Hindi) https://www.youtube.com/watch?v=AddrPKRGdSk
Views: 2989 TechTalkTricks
Difference between delete and truncate - Interview question | OrclData
 
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RUNCATE TRUNCATE is a DDL command TRUNCATE is executed using a table lock and whole table is locked for remove all records. We cannot use Where clause with TRUNCATE. TRUNCATE removes all rows from a table. Minimal logging in transaction log, so it is performance wise faster. TRUNCATE TABLE removes the data by deallocating the data pages used to store the table data and records only the page deallocations in the transaction log. Identify column is reset to its seed value if table contains any identity column. To use Truncate on a table you need at least ALTER permission on the table. Truncate uses the less transaction space than Delete statement. Truncate cannot be used with indexed views. DELETE DELETE is a DML command. DELETE is executed using a row lock, each row in the table is locked for deletion. We can use where clause with DELETE to filter & delete specific records. The DELETE command is used to remove rows from a table based on WHERE condition. It maintain the log, so it slower than TRUNCATE. The DELETE statement removes rows one at a time and records an entry in the transaction log for each deleted row. Identity of column keep DELETE retain the identity. To use Delete you need DELETE permission on the table. Delete uses the more transaction space than Truncate statement. Delete can be used with indexed views.
Views: 74 ANKUSH THAVALI
how to remove duplicates form a table in oracle
 
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removing of duplicates using sql querries
Views: 142 informatica
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: 2928 The Magic of SQL
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: 67169 kudvenkat
MSSQL MERGE STATEMENT | UPDATE + INSERT = UPSERT
 
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Views: 369 Viral Videos
What Is A Row Versus A Column?
 
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"What Is A Row Versus A Column? Watch more videos for more knowledge What is the difference between Rows and Columns ... https://www.youtube.com/watch/0fne5Rs8a-4 Column vs Row - YouTube https://www.youtube.com/watch/T_fL6DXppCE Rows and Columns by Miss Modena - YouTube https://www.youtube.com/watch/0J-3PDj6bK8 SAP HANA - Overview Row vs Column Store - YouTube https://www.youtube.com/watch/dezWmfWKlgg row vs rows vs column vs columns function in excel ... https://www.youtube.com/watch/DRPF_42deck SAP HANA Row vs Column store tables - YouTube https://www.youtube.com/watch/jerczCx8nmQ Rows Oriented Database versus Column Oriented ... https://www.youtube.com/watch/doQfVHGfFJA Column vs Row Percentages - YouTube https://www.youtube.com/watch/cdvTpnHwKjs Rows Versus Columns: Which One Is Best For You ... https://www.youtube.com/watch/u5LfQp4vQKs Formatting Data: What Makes Up a Column? - YouTube https://www.youtube.com/watch/hd8AWOtbp58 14.216 Data Layouts: Row Layout vs Column ... https://www.youtube.com/watch/I-jnZ22r7fY Row Store vs Column Store - YouTube https://www.youtube.com/watch/5I-qI0o1COU Excel - Row, Rows, Column & Columns Function ... https://www.youtube.com/watch/B0zEevKZp5Y What is a Columnar Database? - YouTube https://www.youtube.com/watch/8KGVFB3kVHQ Difference Between Row Level Storage(Oracle ... https://www.youtube.com/watch/Er7JhYO-k3E Difference between rows and range - YouTube https://www.youtube.com/watch/hM1YKSxltDU What are Periods and Groups in the Periodic Table ... https://www.youtube.com/watch/7mLPC74GHMo How to Sum a Column or Row of Excel Cells - YouTube https://www.youtube.com/watch/b6zOxPCKf6A Freeze or Lock Row and Column Separately or ... https://www.youtube.com/watch/orEj68Mt5h8 Excel INDEX Function Gets Value from Row and ... https://www.youtube.com/watch/ZPBbWRtUZWk"
Views: 17 Ask Question II
Oracle APEX -  Interactive Gird with Javascript
 
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Interactive Grid Interface By default, all interactive grids have a search bar, Actions menu, and Reset button. All grids also have Column Heading Menus, which users access by clicking the name or heading of a column. With the Actions and Column Heading menus, users can hide, filter, freeze, highlight, sort, and create control breaks on individual columns. Advanced users can also define aggregations, which appear at the bottom of the column or column group. Users can directly customize the appearance of an interactive grid with the mouse. Users can resize or drag and drop columns into different places in the grid. The width and order of columns can also be configured in the Columns dialog. Users can quickly chart the data with the Chart function. This feature is useful for quick data visualization or even presentation, and responds immediately to changes in the data. Users can quickly revert their modifications with the Reset function, or perform an incremental revert with the Flashback function. In cases of a highly dynamic data set, users can use the Refresh function to pull in the latest version of the data on the database. Editable Interactive Grids Oracle Application Express also contains editable interactive grids, which provide a more robust tool set for directly editing data in the interactive grid.
Views: 1714 Oracle Apex
Peter Geoghegan: Concurrency in Postgres
 
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This talk gives an overview of: How Postgres implements the various isolation levels described by the SQL standard, and the visibility rules and exact set of guarantees made by each level. The various locks that Postgres acquires on tables, indexes, rows and transactions, and even query predicates, and how all of this fits together with the isolation modes. Other ways in which the isolation modes handle conflict resolution. How Postgres locks can be represented as a tree, with cascading lock dependencies, and how this information can be interpreted to find backends that block other backends without being blocked themselves (the "real offenders") using a recursive SQL query. Common scenarios in which race condition bugs can be inadvertently added to applications, and how you can avoid them. How to write queries to avoid locking issues such as deadlocks. New improvements to foreign key locking added to Postgres 9.3, and what they mean for your application. How to implement UPSERT (i.e. atomic insert-or-update) correctly, in the absence of core functionality to take care of this for you.
Views: 1923 Postgres Open
What is that one thing that can fix all performance issues - DBPerf Video 03
 
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. Our Upcoming Online Course Schedule is available in the url below https://docs.google.com/spreadsheets/d/1qKpKf32Zn_SSvbeDblv2UCjvtHIS1ad2_VXHh2m08yY/edit#gid=0 Reach us at [email protected]
Views: 2995 Ramkumar Swaminathan
Why UPSERT is weird
 
52:43
by Peter Geoghegan Counterintuitive lessons learned from the implementation effort Talk that examines implementation process on the INSERT...ON DUPLICATE KEY LOCK FOR UPDATE feature proposed for PostgreSQL. "UPSERT" can loosely be described as a DBMS feature that allows a DML statement's author to atomically either insert a row, or on the basis of the row already existing, update that existing row instead, while safely giving little to no further thought to concurrency. One of those two outcomes must be guaranteed, regardless of concurrent activity, which is the essential property of UPSERT. Examples include MySQL's INSERT...ON DUPLICATE KEY UPDATE, or the SQL standard's MERGE statement (as implemented in a number of proprietary systems). The absence of this feature from Postgres has been a long-standing complaint from Postgres users, and an effort to implement an extension to the Postgres INSERT statement, that implements something broadly in line with user expectations in this area was undertaken in 2013. This talk considers the experience of working on that implementation, and examines how the proposed INSERT...ON DUPLICATE KEY LOCK FOR UPDATE feature deals with concurrency issues, visibility issues, the interplay of value locking and row locking, and the general avoidance of unprincipled deadlocking. In order to come up with an implementation that satisfied user expectations, while still preserving and respecting long standing abstractions and conceptual precepts, some interesting and counterintuitive choices were made to resolve the fundamental tension in tying value locking (as always required on a limited scale for unique index enforcement) to row locking (to LOCK FOR UPDATE). Finally, the talk examines the strategic significance of UPSERT, and further use-cases enabled by the feature in the area of multi-master replication conflict resolution.
Views: 563 Andrea Ross