文件名称：Introduction to Transactions
文件大小：279KB
文件格式：PPTX
更新时间：2019-03-06 06:23:30
Introduction to Transactions
A transaction is a program module that starts with ‘begin transaction’ statement, and execution ends in ‘commit transaction’ or ‘rollback transaction’. Syntax differs from one system to another normally includes its own computational statements (unbeknown to the DBMS) and requests for some database retrieval/update operations. is normally performed in an online environment: when ‘commit transaction’ statement returns, the updated data are effective immediately. when ‘rollback transaction’ statement returns, the effect of data modifications by the Xact will have been undone.