The Impact Manager module can only perform data model updates if it is allowed to harvest metadata information out of the Interactive Reporting documents that are imported into the common repository. Information can be harvested as documents are imported, or harvesting can take place when the administrator requests a synch operation. Harvested metadata is placed in a set of 28 tables that start with “V8_H_”.
A synch operation causes the Synchronize Metadata Feature to look at all imported documents. If metadata for a document does not exist in the V8_H_ tables, or if the document is more recent than its metadata in the V8_H_ tables, then it needs to be harvested.
The time required to harvest an Interactive Reporting document and the amount of space required to store the information, depend on the complexity of the structures in the Interactive Reporting document. As harvesting does not look at data, a very large but simple Interactive Reporting document (say with just a query and a result section) might only require a fraction of the time and space required for a small Interactive Reporting document that contains dozens of queries, results, pivots, charts, reports, and dashboard sections.
The following guidelines are indicative of what has been observed when harvesting a variety of documents.
For a random set of around 800 documents:
Average time to harvest a document—15 seconds
Average space for a document—30 KB
For a complex set of documents:
Average time to harvest a document—60 seconds
Average space for a document—150 KB
To ensure there are no space shortage problems, it is recommended that 100K per imported document be allocated. Each version is a document, so it is important not to forget these when allocating size.
A synch of a repository with 1,000 documents is likely to take over 4 hours to complete.