Hashed file caching

When a Hashed File stage writes records to a hashed file, there is an option for the write to be cached rather than written to the hashed file immediately.

About this task

Similarly, when a Hashed File stage is reading a hashed file there is an option to pre-load the file to memory, which makes subsequent access very much faster and is used when the file is providing a reference link to a Transformer stage. (UniData® Stages also offer the option of preloading files to memory, in which case the same cache size is used.)

The Hashed file stage area of the Tunables page lets you configure the size of the read and write caches.

Procedure

  1. To specify the size of the read cache, enter a value between 0 and 999 in the Read cache size (MB) field. The value, which is in megabytes, defaults to 128.
  2. To specify the size of the write cache, enter a value between 0 and 999 in the Write cache size (MB) field. The value, which is in megabytes, defaults to 128.
  3. Click OK to save your changes.
Parent topic: Tunables page