You can configure a Lookup transformation to use a persistent cache. When you use a persistent cache,
Data Integration
saves and reuses the cache files from mapping run to mapping run.
By default,
Data Integration
uses a non-persistent cache when you enable caching in a Lookup transformation. When you use a non-persistent cache,
Data Integration
deletes the cache files at the end of the mapping run. The next time you run the mapping,
Data Integration
builds the memory cache from the database.
If the lookup table does not change between mapping runs, you can use a persistent cache. A persistent cache can improve mapping performance because it eliminates the time required to read the lookup table. The first time that
Data Integration
runs a mapping using a persistent lookup cache, it saves the cache files to disk. The next time that
Data Integration
runs the mapping, it builds the memory cache from the cache files.
Configure the Lookup transformation to use a persistent lookup cache in the transformation advanced properties. To use a persistent cache, enable the
Lookup Cache Persistent
property.
You can configure the following options when you use a persistent cache:
Specify a name for the cache files.
When you use a persistent lookup cache, you can specify a name for the cache files.
To specify a name, enter the file name prefix in the
Cache File Name Prefix
field on the
Advanced
tab of the Lookup transformation. Do not enter a suffix such as .idx or .dat.
Rebuild the lookup cache.
If the lookup table changes occasionally, you can configure the Lookup transformation to rebuild the lookup cache. When you do this,
Data Integration
rebuilds the lookup cache from the lookup source when it first calls the Lookup transformation instance.
To configure the transformation to rebuild the cache, enable the
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