Once you have created your XML definition file, the ATG platform can generate the XHTML documents and load them into ATG Search for indexing. Depending on the needs of your site, this may be an operation that is performed occasionally (if the content rarely changes) or frequently (if the content changes often). To be as flexible as possible, the ATG platform provides two approaches to loading the data:
Bulk loading loads all of the data generated from a repository into ATG Search. Each time a bulk load is performed, the ATG platform creates and loads the complete set of XHTML documents for the repository, and ATG Search builds a complete new index.
Incremental loading loads only the data that has changed since the last load. The ATG platform determines which repository items have changed since the last incremental or bulk load, and creates and loads the XHTML documents for those items. ATG Search then incrementally indexes those documents.
Bulk loading and incremental loading are not mutually exclusive. For some sites, only bulk loading will be necessary, especially if site content is updated only occasionally. For other sites, incremental loading will be needed to keep the search content up to date, but even for those sites it is important to perform a bulk load occasionally to ensure the integrity of the indexed data. In particular, if you make any structural changes to an indexed repository, you should run a bulk load so ATG Search builds a complete index to replace the existing index.
In addition to configuring the Nucleus components described in this section, you must also create a project in ATG Search Administration that manages the indexing process. You configure the project by specifying the content to be indexed and various additional parameters, such as text processing options or a schedule for performing the indexing. For example, you might schedule incremental indexing to take place every four hours, and schedule bulk indexing to be performed once a week. For more information, see the ATG Search Administration Guide.