File Control Table (File architecture): Difference between revisions

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<p>The FCT is 8 pages.</p>
<p>The FCT is 8 pages.</p>


<p>The FCT contains:</p>  
<p>The first page of the FCT is the The File Parameter List (FPL) page, which contains :</p>  


* The File Parameter List (FPL)
* The File Parameter List holding the current parameter settings for the file
* The Logical Page Map (LPM) which shows the distribution of the pages within the file
* The Logical Page Map (LPM) which shows the distribution of the pages within the file
* The datasets list (DSL) of those which comprise this file
* The datasets list (DSL) comprising the name and number of pages in each dataset
* The shared DASD enqueue list  
* The shared DASD enqueue list  
* The current file [[BROADCAST command: Sending a file message|broadcast]] message (if any)   
** controls access to the file by multiple jobs
** contains the enqueue level of each of those jobs
** see the [[ENQCTL command]] to see how to display this
* The current file [[BROADCAST command: Sending a file message|broadcast]] message (if any), displayed when the file is [[OPEN FILE command|OPEN]]ed.  





Revision as of 00:45, 4 April 2013

The File Control Table contains the file parameter settings, data set or file definition names of all data sets in the file, the status of the file, and other control information.

The FCT is 8 pages.

The first page of the FCT is the The File Parameter List (FPL) page, which contains :

  • The File Parameter List holding the current parameter settings for the file
  • The Logical Page Map (LPM) which shows the distribution of the pages within the file
  • The datasets list (DSL) comprising the name and number of pages in each dataset
  • The shared DASD enqueue list
    • controls access to the file by multiple jobs
    • contains the enqueue level of each of those jobs
    • see the ENQCTL command to see how to display this
  • The current file broadcast message (if any), displayed when the file is OPENed.