Author: steve.ebersole(a)jboss.com Date: 2009-06-10 14:33:44 -0400 (Wed, 10 Jun 2009) New Revision: 16744 Modified: core/trunk/documentation/manual/src/main/docbook/en-US/content/transactions.xml Log: added a definition of UoW Modified: core/trunk/documentation/manual/src/main/docbook/en-US/content/transactions.xml =================================================================== --- core/trunk/documentation/manual/src/main/docbook/en-US/content/transactions.xml 2009-06-10 18:21:29 UTC (rev 16743) +++ core/trunk/documentation/manual/src/main/docbook/en-US/content/transactions.xml 2009-06-10 18:33:44 UTC (rev 16744) @@ -92,6 +92,23 @@ <title>Unit of work</title> <para> + First, let's define a unit of work. A unit of work is a + design pattern described by Martin Fowler as + <quote> + [maintaining] a list of objects affected by a business + transaction and coordinates the writing out of changes + and the resolution of concurrency problems. + </quote><citation>PoEAA</citation> + In other words, its a series of operations we wish to carry out + against the database together. Basically, it is a transaction, + though fulfilling a unit of work will often span multiple + physical database transactions (see <xref linkend="transactions-basics-apptx"/>). + So really we are talking about a more abstract notion of a + transaction. The term "business transaction" is also sometimes + used in lieu of unit of work. + </para> + + <para> Do not use the <emphasis>session-per-operation</emphasis> antipattern: do not open and close a <literal>Session</literal> for every simple database call in a single thread. The same is true for database transactions. Database calls