Write to Cache loads output from a dataflow into a global cache, making the data available for lookup from the Query Cache stage. Using a global cache for data lookups improves performance compared to lookups to databases.
A global cache is system-wide, shared cache that will reside in memory. Choose a global cache if you want the cache to be available to multiple dataflows or when data does not change often or remains relatively static and when storage is not limited. A global cache is static as you can write to it only once. The cache can not be updated once it has been created.
The cache size is set to 500K records (default). You can configure it by using the following property of jmx-console:
MBean: com.pb.spectrum.edi.managers.config.impl:manager=EDIGlobalCacheConfigManager
Description: Data Global Cache Configuration Manager
MaxCacheSize = 500000
General
Option Name |
Description |
---|---|
Cache name |
Specifies the name you want to give to the cache. If there are caches already on the system, they are listed and you can choose one if you want to populate the existing cache with new data. To create a new cache, type the name you want for the new cache. The name must begin with a letter. It can contain an underscore but no other special characters. The name can contain numeric values. |
Cache Fields |
This column lists the field names that will be used in the cache. If you wish to change a field name, click the field name and enter a new name. |
Stage Fields |
This column lists the field names used in the dataflow. You cannot modify these field names. |
Type |
This column lists the data type of each field. |
Include |
Check the box in this column to have the field written to the cache. Clear the box if you do not want the field written to the cache. |
Key Field |
Check the box in this column if you want the field to be used as a key in the Query Cache stage. For example, if you have a dataflow field named AccountNumber and you want the Query Cache stage to look up data by querying for a matching value in the AccountNumber field, you would check the box in the Key Field column for the AccountNumber field. The fields you specify as key fields are available for selection in the Query Cache stage as key fields. |