Caching rows
The CachedRowTransformation does basically the same as the RowTransformation, but has a cache to access previously processed data rows.
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Overview
The CachedRowTransformation
has the same functionality as the RowTransformation
, but offers additionally a cache manager object to access previously processed data rows.
Cache Manager
The CachedRowTransformation comes with a default CacheManager which stores already processed rows in memory.
Buffer
The CachedRowTransformation
is a non-blocking transformation and has one input buffer. Additionally, the memory consumption will depend on the cache size.
Code snippet
The following example will check for an incoming row if a record with the same id was already processed within the previous 10 records. If so, it will return null, other wise the record. A predicate expression the LinkTo method will send null values into a void destination.
Example
The following example will write the content of the cached records into the Console output. The MaxCacheSize of the cache manager is set to 10, so you will never get more than 10 lines of output written here.