Specifying a buffer size for Express data

When a user creates a report that contains Express data, that data must be fetched from Express Server and stored in a memory buffer before it is displayed. Once the data is fetched and displayed, the memory is released. If there is insufficient memory to hold all the data that is being fetched, then an error is displayed. For example, you might see an error message that states that a null or invalid value was passed for a mandatory parameter or that states that an Express operation was unsuccessful.

The default buffer size is generally sufficient for most circumstances, and you can probably accept the default size of the buffer and not worry about making any changes.

You can specify a larger or smaller size for the buffer than the default value specifies. For example, if users generate many small reports, then you might want to reduce the buffer size. If users generate very large reports, then you might need to increase the size.

Changing the default buffer size

You change the default size of the buffer in the xrpdsprefs.ora file. You must bear in mind that you create this file and that it resides on the Reports Builder machine and on the Reports Server machine.

Buffer sizes

The following list describes some of the buffer sizes:

Specifying the buffer size

To specify the buffer size:
  1. On the machine where Reports Builder is running, open the xrpdsprefs.ora file, if it exists in the ORACLE_HOME/reports/jlib (on Windows) or ORACLE_HOME/jlib (on UNIX) directory.

    If the file does not exist, then use a text editor to create xrpdsprefs.ora.

  2. Scroll to or create the options.snapi.FetchAlloc line.

    This setting defines the buffer size, as shown in the following examples. You enter a value that can include commas (such as 6,000,000) or the characters M for megabytes or K for kilobytes.

    options.snapi.FetchAlloc=6M
    options.snapi.FetchAlloc=6000K
    options.snapi.FetchAlloc=6,000K
    options.snapi.FetchAlloc=6,000,000
  3. Save your changes and close the file.