FYI - we are hoping to add this information to the P8 KC in the next release:Performance and storage costs
For both static and dynamic summaries, a portion of the indexed text for a document is retained in the full-text index for generating the summary. By default, the maximum amount of this retained text is 512 characters for static summaries and 10 K characters for dynamic summaries. The difference in these default values indicates how large the retained text must be for dynamic summaries to be functionally effective. Of more significance, however, is the way that retained text must be stored. Roughly, additional disk space for 4 times the number of characters to be retained is required. As a result, a full-text index with dynamic summary holds fewer documents compared to same size full-text index with static or no summary.
In addition to this storage cost, dynamic summaries cause slower performance for indexing and searching because of the following factors:
The greater amount of retained text for dynamic summaries means more disk I/O to write and read that text. This increased disk I/O affects both indexing and searching.
The greater amount of retained text for dynamic summaries increases the size of the full-text indexes. Generally, indexing and searching tend to be slower for larger indexes than for smaller indexes.
A dynamic summary requires that the relevant text fragments be found and the positions of the search hits within those fragments be calculated. CBR queries run more slowly because of this increased processing.
How to enable dynamic summary and hit highlighting
CBR Summary Type Dynamic
CBR Summary Indexing Size 1024
CBR Results Size 1024
Save your changes. * Important* this will ONLY work if the word or term searched for exists in the first 1024kb of the document.