CAPI.StartTransaction() and CAPI.EndTransaction question

Does CAPI.StartTransaction() and CAPI.EndTransaction() functions help to avoid database deadlocks, while updating table? Thanks

Find more posts tagged with

Comments

Appu_Nair1

It keeps connections to the database in a manageable stateA best practicehttp://en.m.wikipedia.org/wiki/Database_transactionIn oscript capi documentation implementation details/examples are given as wellI do not know how db locks occur either could be really unoptimized queries to the DBSent with Good (www.good.com)-----Original Message-----From: eLink Entry: Content Server Development Forum [development@elinkkc.opentext.com]Sent: Sunday, February 03, 2013 02:38 AM Central Standard TimeTo: eLink RecipientSubject: [EXTERNAL]CAPI.StartTransaction() and CAPI.EndTransaction questionCAPI.StartTransaction() and CAPI.EndTransaction question Posted by e.ochkurov@sibcon-soft.ru (Ochkurov, Eugene) On 02-03-2013 03:33Does CAPI.StartTransaction() and CAPI.EndTransaction() functions help to avoid database deadlocks, while updating table? Thanks________________________________[To post a comment, use the normal reply function]Forum: Content Server Development ForumContent Server: Knowledge Center

David Templeton

Eugene

While content server uses implicit transactions, the use of the transaction mechanisms in the code is essential. That being said, the CAPI.*Transaction calls are lower level calls and should not be used by solutions. I have seen code that does execute SQL without transactions, this usually leads to inconsistent data and lockup’s :-) The recommended method where possible is to use the dapiCtx or similar higher level transaction API’s such as:

Object dapiCtx = prgCtx.DSession()

if( dapiCtx.StartTrans() )

// Your code here

//end the transaction.

if ( ( dapiCtx.EndTrans( ok ) != TRUE ) && ok )

ok = FALSE

errMsg = “Could not end transaction”

end

else

ok = FALSE

errMsg = [LLIAPI_ERRMSG.UnableToStartTransaction_]

end

By using these, nesting of these blocks set up a reference count that will then issue a single transaction commit at the top level ( reference count = 0 ).

For the deadlocks there are a couple of items to check on:

<![if !supportLists]>1. <![endif]>For MSSQL, ensure the read committed snapshot is set.

<![if !supportLists]>2. <![endif]>For updates to tables where multiple changes are required that the same order of SQL is being executed. For instance this will cause a deadlockJ:

<![if !supportLists]>a. <![endif]>Table one update

<![if !supportLists]>b. <![endif]>CAPI.iniput

<![if !supportLists]>c. <![endif]>Capi.inidelete

<![if !supportLists]>d. <![endif]>Table one update

<![if !supportLists]>3. <![endif]>Use the database tracing to pinpoint the deadlocks…

Does that help?

Regards

David Templeton

OpenText Corporation

From: eLink Entry: Content Server Development Forum [mailto:development@elinkkc.opentext.com]
Sent: Sunday, February 03, 2013 3:38 AM
To: eLink Recipient
Subject: CAPI.StartTransaction() and CAPI.EndTransaction question

CAPI.StartTransaction() and CAPI.EndTransaction question

Posted bye.ochkurov@sibcon-soft.ru (Ochkurov, Eugene) On 02-03-2013 03:33

Does CAPI.StartTransaction() and CAPI.EndTransaction() functions help to avoid database deadlocks, while updating table? Thanks

[To post a comment, use the normal reply function]
Forum:	Content Server Development Forum
Content Server:	Knowledge Center

Eugene_Ochkurov

Thanks, David