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Showing posts with label difference between execute immediate and execute deferred. Show all posts
Showing posts with label difference between execute immediate and execute deferred. Show all posts

Tuesday 6 September 2011

Difference Between Execute Immediate and Execute Deferred


  • Deferred custom actions can only be sequenced between the InstallInitialize and InstallFinalize actions in execute sequence tables. Immediate custom actions, on the other hand, can be sequenced anywhere within any of the sequence tables.
  • Deferred custom actions cannot access the installation database. In fact, deferred custom actions have very limited access to the installation session because an installation script can be executed outside of the installation session that created it. Immediate custom actions have access to the installation database and can read and set installation properties, modify feature and component states, and add temporary columns, rows, and tables among other things.
  • While both deferred and immediate custom actions can run in the context of the user initiating the installation, only deferred custom actions can run elevated using the system context.




  • Deferred custom actions are not executed immediately. Instead they are scheduled to run later during the execution script. The execution script isn't processed until the InstallExecute, InstallExecuteAgain, or InstallFinalize action is run.