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 File Size Estimates with the File Size Worksheet

Purpose

To plan for system resources required for data extracts on your application server, the File Size Worksheet utility helps you estimate some important key figures:

  • The size of the resulting extract file, both compressed and uncompressed.

  • The size of temporary sort files, that is, work files used by the system for sorting the extracted data.

    Note Note

    The sort directory is defined per application server. If you are looking at the estimates for the sort file size, then perform the estimates on the application server on which your users will extract data.

    End of the note.
  • The size of sort memory ( maximum memory allocation ) required to hold index records during extraction until the segment is complete.

  • Runtime of the extraction.

Process Flow

To estimate the effect of compression on the size of the extract file, and to calculate the run time of data extracts more accurately, the system uses a log from previous runs of data extraction.

  1. If there is no history of data extraction on your system, the system makes certain assumptions, which may result in less accurate estimates. To increase the accuracy of the estimates, you can provide the system with a "base case" , by running a subset of an extraction before using the estimate utility.

  2. After creating an extract base case, or if someone has already performed an extract on your system, you can use this utility to obtain the estimates for a data extract .