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.
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.
On the Reports Builder machine, the file is used for a single user.
On the Reports Server machine, the file is shared by many users. The server allocates the same size buffer to all users of that server for the duration of the time that data is being fetched from Express Server. Use care when specifying the size to fit the needs of the many users who are concurrently accessing Express data. The size should be large enough to allow users to fetch the data for their reports while ensuring that the server has sufficient memory.
The following list describes some of the buffer sizes:
64KB: This is the minimum buffer size that is allowed. Even if you specify a smaller size, the buffer has a size of 64KB.
2MB: This is the default buffer size. If you do not specify a different size, then the buffer has a size of 2MB.
50MB: This is the maximum buffer size that is allowed. Even if you specify a larger size, the buffer has a size of 50MB. You must ensure that the server has a very large amount of memory before specifying such a large buffer size.
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
.
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
Save your changes and close the file.
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