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  • What transaction manager should I use for JBDC template When using JPA ?

    - by Sajid
    I am using standard JPA transaction manager for my JPA transactions. However, now I want to add some JDBC entities which will share the same 'datasource'. How can I make the JDBC operations transactional with spring transaction? Do I need to swith to JTA transaction managers? Is it possible to use both JPA & JDBC transactional service with same datasource? Even better, is it possible to mix these two transactions?

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  • How to config a default global EJB transaction attribute in JBoss Server?

    - by seven
    my project need to migrate from oc4j to jboss. But it seems that default EJB transaction attribute is different between them. For OC4J: If you do not specify any transaction attributes for an EJB method then OC4J uses default transaction attributes. OC4J by default uses Required for CMP 2.0, NotSupported for MDBs and Supports for all other types of EJBs. (refer to official doc) For JBoss: default for all types EJB is Required. (Maybe , refer to un-official site) To migrate my project within less effort, how to config a default global EJB transaction attribute, e.g. Supports, in JBoss Server?

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  • Would this prevent the row from being read during the transaction?

    - by acidzombie24
    I remember an example where reads in a transaction then writing back the data is not safe because another transaction may read/write to it in the time between. So i would like to check the date and prevent the row from being modified or read until my transaction is finish. Would this do the trick? and are there any sql variants that this will not work on? update tbl set id=id where date>expire_date and id=@id Note: dateexpire_date happens to be my condition. It could be anything. Would this prevent other transaction from reading the row until i commit or rollback?

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  • How to avoid StaleObjectStateException when transaction updates thousands of entities?

    - by ThinkFloyd
    We are using Hibernate 3.6.0.Final with JPA 2 and Spring 3.0.5 for a large scale enterprise application running on tomcat 7 and MySQL 5.5. Most of the transactions in application, lives for less than a second and update 5-10 entities but in some use cases we need to update more than 10-20K entities in single transaction, which takes few minutes and hence more than 70% of times such transaction fails with StaleObjectStateException because some of those entities got updated by some other transaction. We generally maintain version column in all tables and in case of StaleObjectStateException we generally retry but since these longs transactions are anyways very long so if we keep on retrying then also I am not very sure that we'll be able to escape StaleObjectStateException. Also lot of activities keep updating these entities in busy hours so we cannot go with pessimistic approach because it can potentially halt many activities in system. Please suggest how to fix such long transaction issue because we cannot spawn thousands of independent and small transactions because we cannot afford messed up data in case of some failed & some successful transactions.

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  • How to close the connection after set Transation to Nothing or Commit/Rollback

    - by user1957271
    I develop the DAL class for db operation Public Sub StartTransaction() Dim objConnection As SqlConnection = EstablishConnection() objConnection.Open() Me.Transaction = objConnection.BeginTransaction() End Sub Public Sub CommitTransaction() Me.Transaction.Commit() End Sub Public Sub RollBackTransaction() Me.Transaction.Rollback() End Sub after start the transaction when we commit or rollback and set transaction object to nothing it dont close the connection attach with this transaction how I close the Connection attach to this transaction???

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  • Increasing deadlocks with NoLock

    - by Dave Ballantyne
    One on my personnel pet issues is with inappropriate use of the NOLOCK hint (and read uncommitted) .  Dont get me wrong, I have used it in exceptional circumstances , but as a general statement it is a bad thing.  Mostly , when NOLOCK, is used the discussion is around a single statement,  “it runs faster with nolock for XYZ reason”,  however ,IMO, this is quite a shorted sighted view.  What about the Transaction ? What about other concurrent users ?  What is good for one statement in isolation , does not mean that it is good for the system as a whole.  I have seen on a number of occasions deadlocks happen, when tasks that would of(and should of) be blocked continue to execute, only for a deadlock to occur at a later data writing (INSERT,UPDATE,DELETE) statement.  Writers will block writers regardless of isolation level. By Way of (fairly contrived ) example , lets generate some dummy tables and populate with some data drop table a go drop table b go Create Table a ( col1 integer ) go insert into a values(1) insert into a values(2) go Create Table b ( col1 integer ) go insert into b values(1) insert into b values(2) go   Now make two connections. In connection one execute set transaction isolation level read committed BEGIN TRAN Select * from a Select * from b delete from a In connection two execute set transaction isolation level read committed BEGIN TRAN Select * from a Select * from b delete from b Right now the ‘select from a’ in connection two is being blocked by the ‘delete from a’ in connection one.  This is ,IMO, quite a healthy and natural thing to be happening , some see this as a ‘slow down’, a drop in performance.  So, lets reach for our ‘NOLOCK’ magic pill.  Cancel the blocked query and ROLLBACK both transactions, then in connection one execute set transaction isolation level read uncommitted BEGIN TRAN Select * from a Select * from b delete from b and then in connection two execute set transaction isolation level read uncommitted BEGIN TRAN Select * from a Select * from b delete from a We have now solved out performance problem , no more blocking.  Lets finish the work required by the transaction, in connection one , execute delete from a Oh, ‘ performance problem’ again , its now being blocked. Still, lets complete the work in connection two…. delete from b DEADLOCK!!  It is important to be clear about the role of the select statements.  They do not participate within the deadlock, but are preventing code executing that would of.   Additionally, without the select readers to block, a deadlock would occur on the deletes with READ COMMITTED. Naturally, other isolation levels will exhibit different behaviour as to where and when they will and wont block,  and I would encourage you to read BOL and satisfy yourself that you really do NEED to NOLOCK.

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  • How to deal with Warning : "Uncommittable transaction is detected at the end of the batch. The trans

    - by VishnuTiwariBlog
    Hi, If you are integrating with SQL Server and dealing with batch messages, you may encounter this problem. And this is evitable. The reason is the contention of resources. If your batch contains four messages and all the four messages have to be updated to SQL Server and then at the same time four process will contend for SQL server table and resources and the obvious result will be, few of your transaction will be left uncomitted and if you are not handling dehydration [not modifying the default property of the Dehydration] then your orchestration will dehydrate and will go for retry. If retry is set for every five minutes then after five minutes Port will send the message to the database. Reason for writing this post was as I did not want to see so many DEHYDRATED messages. And this was happening as Host Throttling was not set. Thus as soon as the BizTalk Process finds that SQL resources are unavailable it will go and dehydrate that process and process will go for retry. The contension of resources is unavoidable though we can fine tune the Dehydration setting. If you increase the time that an orchestration can be blocked at a subscription before being dehydrated, possibly you will give more time BizTalk Engine to handle to SQL resource availability. At least I solve the problem by fine tuning the Dehydration properties. Below is the section of config info which you need to add to the BTSNTsvc.exe.config.   <?xml version="1.0" ?> <configuration>        <configSections>               <section name="xlangs" type="Microsoft.XLANGs.BizTalk.CrossProcess.XmlSerializationConfigurationSectionHandler, Microsoft.XLANGs.BizTalk.CrossProcess" />        </configSections>        <runtime>               <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">                      <probing privatePath="BizTalk Assemblies;Developer Tools;Tracking" />               </assemblyBinding>        </runtime>        <xlangs>               <Configuration>                      <Dehydration MaxThreshold="1800" MinThreshold="1" ConstantThreshold="-1">                             <VirtualMemoryThrottlingCriteria OptimalUsage="900" MaximalUsage="1300" IsActive="true" />                             <PrivateMemoryThrottlingCriteria OptimalUsage="50" MaximalUsage="350" IsActive="true" />                             <PhysicalMemoryThrottlingCriteria OptimalUsage="50" MaximalUsage="350" IsActive="false" />                      </Dehydration>               </Configuration>        </xlangs> </configuration>

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  • Database Error Handling: What if You have to Call Outside service and the Transaction Fails?

    - by Ngu Soon Hui
    We all know that we can always wrap our database call in transaction ( with or without a proper ORM), in a form like this: $con = Propel::getConnection(EventPeer::DATABASE_NAME); try { $con->begin(); // do your update, save, delete or whatever here. $con->commit(); } catch (PropelException $e) { $con->rollback(); throw $e; } This way would guarantee that if the transaction fails, the database is restored to the correct status. But the problem is that let's say when I do a transaction, in addition to that transaction, I need to update another database ( an example would be when I update an entry in a column in databaseA, another entry in a column in databaseB must be updated). How to handle this case? Let's say, this is my code, I have three databases that need to be updated ( dbA, dbB, dbc): $con = Propel::getConnection("dbA"); try { $con->begin(); // update to dbA // update to dbB //update to dbc $con->commit(); } catch (PropelException $e) { $con->rollback(); throw $e; } If dbc fails, I can rollback the dbA but I can't rollback dbb. I think this problem should be database independent. And since I am using ORM, this should be ORM independent as well. Update: Some of the database transactions are wrapped in ORM, some are using naked PDO, oledb ( or whatever bare minimum language provided database calls). So my solution has to take care this. Any idea?

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  • How Can I Find What's Causing My Transaction to Get Promoted?

    - by Damian Powell
    I have web site which serves web services (a mixture of .asmx and WCF) which is mostly using LINQ to SQL and System.Transactions. Occaisionally we see the transaction get promoted to a distributed transaction which causes problems because our web servers are isolated from our databases in such a way that it is not possible for us to use MSDTC. I have configured tracing for System.Transactions by adding the following to my web.config: <system.diagnostics> <sources> <source name="System.Transactions" switchValue="Information"> <listeners> <add name="tx" type="System.Diagnostics.XmlWriterTraceListener" initializeData="tx.log" /> </listeners> </source> </sources> </system.diagnostics> It's very interesting and shows me when the transaction is promoted, but I find that it doesn't really help be discover why. Is there an equivalent tracing mechanism for ADO.NET that will show me when connections are created, including the variables that affect pooling (user, cnn string, transaction scope)?

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  • Wireless suddenly dropping with a Ralink RT2870

    - by cwwk
    I have a Linksys WUSB600N v1 Dual-Band Wireless-N Network Adapter Ralink RT2870 USB dongle that worked flawlessly in 11.10. Since upgrading, I can't keep a connection for more than five minutes. The wild world of Google was unable to provide a solution, and I would rather not downgrade although that remains a possibility. Results of syslog: slack@slack:~$ tail /var/log/syslog Apr 26 20:26:10 slack AptDaemon: INFO: Initializing daemon Apr 26 20:26:10 slack AptDaemon.PackageKit: INFO: Initializing PackageKit compat layer Apr 26 20:26:10 slack dbus[972]: [system] Successfully activated service 'org.freedesktop.PackageKit' Apr 26 20:26:10 slack AptDaemon.PackageKit: INFO: Initializing PackageKit transaction Apr 26 20:26:10 slack AptDaemon.Worker: INFO: Simulating trans: /org/debian/apt/transaction/aaed4e38eb3c41ad86d2bab6ca03ee7c Apr 26 20:26:10 slack AptDaemon.Worker: INFO: Processing transaction /org/debian/apt/transaction/aaed4e38eb3c41ad86d2bab6ca03ee7c Apr 26 20:26:12 slack dbus[972]: [system] Activating service name='com.ubuntu.SystemService' (using servicehelper) Apr 26 20:26:12 slack dbus[972]: [system] Successfully activated service 'com.ubuntu.SystemService' Apr 26 20:30:26 slack AptDaemon.PackageKit: INFO: Get updates() Apr 26 20:30:27 slack AptDaemon.Worker: INFO: Finished transaction /org/debian/apt/transaction/aaed4e38eb3c41ad86d2bab6ca03ee7c Any suggestions?

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  • where to enlist transaction with parent child delete (repository or bll)?

    - by Caroline Showden
    My app uses a business layer which calls a repository which uses linq to sql. I have an Item class that has an enum type property and an ItemDetail property. I need to implement a delete method that: (1) always delete the Item (2) if the item.type is XYZ and the ItemDetail is not null, delete the ItemDetail as well. My question is where should this logic be housed? If I have it in my business logic which I would prefer, this involves two separate repository calls, each of which uses a separate datacontext. I would have to wrap both calls is a System.Transaction which (in sql 2005) get promoted to a distributed transaction which is not ideal. I can move it all to a single repository call and the transaction will be handled implicitly by the datacontext but feel that this is really business logic so does not belong in the repository. Thoughts? Carrie

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  • SAP Shortcut file - How to redirect to specific transaction screen in SAP?

    - by Kiru
    Problem : How to redirect the user to a specific executed transaction screen in SAP? Generated the SAP shortcut and able to redirect the user to specific transaction screen. It is also possible to prefill the required input parameters. The corresponding line in the shortcut is- Command=AB12 RIWO00-input1=200001212; where AB12 is the trasaction, and input1 is the input parameter. This will open that SAP screen, with AB12 transaction and the input parameter would be filled with values. But this mandates the user to clicks on enter explicitly/click on execute button explicitly after opening through the shortcut file. Is it possible to include that enter also in the shortcut file? Thank you :)

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  • MySQL Simple query gives "Query was empty". Transaction help needed I think.

    - by user129609
    Hi, I'm trying to do a simple transaction in MySQL delimiter go start transaction; BEGIN DECLARE EXIT HANDLER FOR SQLEXCEPTION, SQLWARNING, NOT FOUND ROLLBACK; INSERT INTO jext_categories (Name) VALUES ('asdfas'); INSERT INTO jext_categories (Name) VALUES ('asdfas2'); END; commit; SELECT * FROM jext_categories; go delimiter ; but I keep getting an error saying query was empty. Could someone please tell me what I am doing wrong, and also, what is the proper format for doing a transaction in MySQL? Thanks!

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  • Can you modify SQL DB schema in a transaction to know if all changes were applied?

    - by Chris F
    As part of my (new) database version control methodology, I'm writing a "change script" and want the change script to insert a new row into the SchemaChangeLog table if the script is executed successfully, or to reverse changes if any single change in the script fails. Is it possible to do schema changes in a transaction and only if it gets committed to then do the INSERT? For example (psuedo-code, I'm not too good with SQL): SET XACT_ABORT ON BEGIN TRANSACTION PRINT 'Add Col2 to Table1' IF NOT EXIST (SELECT * FROM sys.columns WHERE NAME='Col2' AND object_id=OBJECT_ID('Table1')) BEGIN ALTER TABLE [dbo].[Table1] ADD Col2 int NULL END -- maybe COMMIT here? INSERT INTO SchemaChangeLog VALUES(...) COMMIT TRANSACTION

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  • Consolidating separate Loan, Purchase & Sales tables into one transaction table.

    - by Frank Computer
    INFORMIX-SE with ISQL 7.3: I have separate tables for Loan, Purchase & Sales transactions. Each tables rows are joined to their respective customer rows by: customer.id [serial] = loan.foreign_id [integer]; = purchase.foreign_id [integer]; = sale.foreign_id [integer]; I would like to consolidate the three tables into one table called "transaction", where a column "transaction.trx_type" [char(1)] {L=Loan, P=Purchase, S=Sale} identifies the transaction type. Is this a good idea or is it better to keep them in separate tables? Storage space is not a concern, I think it would be easier programming & user=wise to have all types of transactions under one table.

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  • Is it safe to set MySQL isolation to "Read Uncommitted" (dirty reads) for typical Web usage? Even with replication?

    - by Continuation
    I'm working on a website with typical CRUD web usage pattern: similar to blogs or forums where users create/update contents and other users read the content. Seems like it's OK to set the database's isolation level to "Read Uncommitted" (dirty reads) in this case. My understanding of the general drawback of "Read Uncommitted" is that a reader may read uncommitted data that will later be rollbacked. In a CRUD blog/forum usage pattern, will there ever be any rollback? And even if there is, is there any major problem with reading uncommitted data? Right now I'm not using any replication, but in the future if I want to use replication (row-based, not statement-based) will a "Read Uncommitted" isolation level prevent me from doing so? What do you think? Has anyone tried using "Read Uncommitted" on their RDBMS?

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  • Does isolation frameworks (Moq, RhinoMock, etc) lead to test overspecification?

    - by Marius
    In Osherove's great book "The Art of Unit Testing" one of the test anti-patterns is over-specification which is basically the same as testing the internal state of the object instead of some expected output. To my experience, using Isolation frameworks can cause the same unwanted side effects as testing internal behavior because one tends to only implement the behavior necessary to make your stub interact with the object under test. Now if your implementation changes later on (but the contract remains the same), your test will suddenly break because you are expecting some data from the stub which was not implemented. So what do you think is the best approach to counter this? 1) Implement your stubs/mocks fully, this has the negative side-effect of potentially making your test less readable and also specifying more than necessary to make your test pass. 2) Favor manual, fully implemented fakes. 3) Implement your stubs/fakes so that they make your test just pass, and then deal with the brittleness that this might introduce.

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  • Why I am not able to run rails tests

    - by dorelal
    This is what I did. > git clone git://github.com/rails/rails.git > cd rails > cd railties > rake And I got following error. (in /Users/dorelal/dev/scratch/rails/railties) ./test/isolation/abstract_unit.rb:236:in `initialize': No such file or directory - /Users/dorelal/dev/scratch/rails/railties/tmp/app_template/config/boot.rb (Errno::ENOENT) from ./test/isolation/abstract_unit.rb:236:in `open' from ./test/isolation/abstract_unit.rb:236 from ./test/isolation/abstract_unit.rb:222:in `initialize' from ./test/isolation/abstract_unit.rb:222:in `new' from ./test/isolation/abstract_unit.rb:222 from test/application/configuration_test.rb:1:in `require' from test/application/configuration_test.rb:1 rake aborted! I checked ~/railties/tmp and this directory is empty. I know rails is not broken. So what am I missing?

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  • Oracle Flashback Technologies - Overview

    - by Sridhar_R-Oracle
    Oracle Flashback Technologies - IntroductionIn his May 29th 2014 blog, my colleague Joe Meeks introduced Oracle Maximum Availability Architecture (MAA) and discussed both planned and unplanned outages. Let’s take a closer look at unplanned outages. These can be caused by physical failures (e.g., server, storage, network, file deletion, physical corruption, site failures) or by logical failures – cases where all components and files are physically available, but data is incorrect or corrupt. These logical failures are usually caused by human errors or application logic errors. This blog series focuses on these logical errors – what causes them and how to address and recover from them using Oracle Database Flashback. In this introductory blog post, I’ll provide an overview of the Oracle Database Flashback technologies and will discuss the features in detail in future blog posts. Let’s get started. We are all human beings (unless a machine is reading this), and making mistakes is a part of what we do…often what we do best!  We “fat finger”, we spill drinks on keyboards, unplug the wrong cables, etc.  In addition, many of us, in our lives as DBAs or developers, must have observed, caused, or corrected one or more of the following unpleasant events: Accidentally updated a table with wrong values !! Performed a batch update that went wrong - due to logical errors in the code !! Dropped a table !! How do DBAs typically recover from these types of errors? First, data needs to be restored and recovered to the point-in-time when the error occurred (incomplete or point-in-time recovery).  Moreover, depending on the type of fault, it’s possible that some services – or even the entire database – would have to be taken down during the recovery process.Apart from error conditions, there are other questions that need to be addressed as part of the investigation. For example, what did the data look like in the morning, prior to the error? What were the various changes to the row(s) between two timestamps? Who performed the transaction and how can it be reversed?  Oracle Database includes built-in Flashback technologies, with features that address these challenges and questions, and enable you to perform faster, easier, and convenient recovery from logical corruptions. HistoryFlashback Query, the first Flashback Technology, was introduced in Oracle 9i. It provides a simple, powerful and completely non-disruptive mechanism for data verification and recovery from logical errors, and enables users to view the state of data at a previous point in time.Flashback Technologies were further enhanced in Oracle 10g, to provide fast, easy recovery at the database, table, row, and even at a transaction level.Oracle Database 11g introduced an innovative method to manage and query long-term historical data with Flashback Data Archive. The 11g release also introduced Flashback Transaction, which provides an easy, one-step operation to back out a transaction. Oracle Database versions 11.2.0.2 and beyond further enhanced the performance of these features. Note that all the features listed here work without requiring any kind of restore operation.In addition, Flashback features are fully supported with the new multi-tenant capabilities introduced with Oracle Database 12c, Flashback Features Oracle Flashback Database enables point-in-time-recovery of the entire database without requiring a traditional restore and recovery operation. It rewinds the entire database to a specified point in time in the past by undoing all the changes that were made since that time.Oracle Flashback Table enables an entire table or a set of tables to be recovered to a point in time in the past.Oracle Flashback Drop enables accidentally dropped tables and all dependent objects to be restored.Oracle Flashback Query enables data to be viewed at a point-in-time in the past. This feature can be used to view and reconstruct data that was lost due to unintentional change(s) or deletion(s). This feature can also be used to build self-service error correction into applications, empowering end-users to undo and correct their errors.Oracle Flashback Version Query offers the ability to query the historical changes to data between two points in time or system change numbers (SCN) Oracle Flashback Transaction Query enables changes to be examined at the transaction level. This capability can be used to diagnose problems, perform analysis, audit transactions, and even revert the transaction by undoing SQLOracle Flashback Transaction is a procedure used to back-out a transaction and its dependent transactions.Flashback technologies eliminate the need for a traditional restore and recovery process to fix logical corruptions or make enquiries. Using these technologies, you can recover from the error in the same amount of time it took to generate the error. All the Flashback features can be accessed either via SQL command line (or) via Enterprise Manager.  Most of the Flashback technologies depend on the available UNDO to retrieve older data. The following table describes the various Flashback technologies: their purpose, dependencies and situations where each individual technology can be used.   Example Syntax Error investigation related:The purpose is to investigate what went wrong and what the values were at certain points in timeFlashback Queries  ( select .. as of SCN | Timestamp )   - Helps to see the value of a row/set of rows at a point in timeFlashback Version Queries  ( select .. versions between SCN | Timestamp and SCN | Timestamp)  - Helps determine how the value evolved between certain SCNs or between timestamps Flashback Transaction Queries (select .. XID=)   - Helps to understand how the transaction caused the changes.Error correction related:The purpose is to fix the error and correct the problems,Flashback Table  (flashback table .. to SCN | Timestamp)  - To rewind the table to a particular timestamp or SCN to reverse unwanted updates Flashback Drop (flashback table ..  to before drop )  - To undrop or undelete a table Flashback Database (flashback database to SCN  | Restore Point )  - This is the rewind button for Oracle databases. You can revert the entire database to a particular point in time. It is a fast way to perform a PITR (point-in-time recovery). Flashback Transaction (DBMS_FLASHBACK.TRANSACTION_BACKOUT(XID..))  - To reverse a transaction and its related transactions Advanced use cases Flashback technology is integrated into Oracle Recovery Manager (RMAN) and Oracle Data Guard. So, apart from the basic use cases mentioned above, the following use cases are addressed using Oracle Flashback. Block Media recovery by RMAN - to perform block level recovery Snapshot Standby - where the standby is temporarily converted to a read/write environment for testing, backup, or migration purposes Re-instate old primary in a Data Guard environment – this avoids the need to restore an old backup and perform a recovery to make it a new standby. Guaranteed Restore Points - to bring back the entire database to an older point-in-time in a guaranteed way. and so on..I hope this introductory overview helps you understand how Flashback features can be used to investigate and recover from logical errors.  As mentioned earlier, I will take a deeper-dive into to some of the critical Flashback features in my upcoming blogs and address common use cases.

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  • Why can't I shrink a transaction log file, even after backup?

    - by Jordan Hudson
    I have a database that has a 28gig transaction log file. Recovery mode is simple. I just took a full backup of the database, and then ran both: backup log dbmcms with truncate_only DBCC SHRINKFILE ('Wxlog0', TRUNCATEONLY) The name of the db is db_mcms and the name of the transaction log file is Wxlog0. Neither has helped. I'm not sure what to do next.

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  • How do you create a transaction that spans multiple statements in Python with MySQLdb?

    - by Fast Fish
    I know that with an InnoDB table, transactions are autocommit, however I understand that to mean for a single statement? For example, I want to check if a user exists in a table, and then if it doesn't, create it. However there lies a race condition. I believe using a transaction prior to doing the select, will ensure that the table remains untouched until the subsequent insert, and the transaction is committed. How can you do this with MySQLdb and Python?

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