Search in BMC Helix Digital Workplace
How search works
The search bar on the My Activity, Catalog, and studio pages means end users can search multiple sources from a single place and easily find what they need. Sources of search may be catalog items, knowledge articles, locations, and so on. The application performs a federated search, which means that the search phrase is sent to more than ten different search engines, each configured to provide the best possible results from individual search sources. Administrators configure search options for each source. An advanced ranking technology displays the most relevant search results at the top of the list.
The following image shows the different search sources:
As an administrator, you can improve search results by setting the parameters that control different searches. For more information about how to configure search, see Configuring-search.
How search with wildcards works
Wildcard search helps end users find what they’re looking for, even if they don't know the exact term. Wildcards allow users to search for partial terms, alternate spellings, and variations of a term without specifying an exact term match or without having to append the % symbol to a part of a search term. Wildcards broaden the search results and provide a higher chance of finding the required information.
Administrators can enable the use of wildcards when searching for BMC Helix Digital Workplace Catalog items. For more information, see Configuring-search. Also, they can enable the wildcard-related settings for the integrated providers, such as the RKM pluggable provider and Helix ITSM Provider. For example, if administrators enable the rkm.search.force.wildcards setting in the RKM pluggable provider, users can search by entering only parts of the title. Learn more about enabling search-related settings for the pluggable providers in Integrating-with-other-applications-by-using-providers. These settings are disabled by default because they interfere with the full-text search, language-specific tokenization, stemming, and relevance logic. For certain sources, wildcards are always supported, and the administrator doesn't have an option to disable them; for example, appointments.
Types of wildcards in BMC Helix Digital Workplace
BMC Helix Digital Workplace supports two types of wildcards:
- Leading wildcard—End users can omit the beginning of a search term and don't need to append the % symbol before the search query. The leading wildcard automatically matches any characters that precede the specified search query. For example, if the end user enters flow, the search might return workflow in the results.
- Trailing wildcard—End users can omit the end of a search term and don't need to append the % symbol after the search query. The trailing wildcard automatically matches any characters that follow the specified search query. For example, if the end user enters work, the search might return workflow and workaround terms in the results.
The actual search results with wildcards may vary from the results that users expect to receive. The search results are determined by the following factors:
- Sources that end users search for by using wildcards.
Not all sources support the wildcard search. For example, end users can't search for BMC Helix Digital Workplace locations and assets by using wildcards. This use case is different from enabling wildcards. For certain sources, the wildcard search is not supported, and the administrator has no options to enable it. - Fields by which the search is executed.
When end users perform a wildcard search, the system searches in records that are associated with a searched-for source and retrieves information from the designated fields within these records. While searching in the fields, the system analyzes whether these fields are indexed for Full Text Search (FTS) or not. For example, when the end user searches for a catalog service in the Global search field by using the wildcard, the search is performed by the Title, Description, and Tag fields, and the search checks whether these fields are indexed for FTS.
List of sources that support the wildcard search
The following table lists the sources that support the wildcard search and indicates whether each source supports both leading and trailing wildcards or only trailing wildcards:
The indicated list of sources might not be exhaustive, and additional sources might be supported.
How search results are ranked by relevance
Search results for different sources are returned by using an improved ranking technology. The setting displays the most relevant results at the top of all results. The content of the primary search results from the different sources is re-ranked by using the Okapi BM25 ranking function. During this second round of ranking, the search result data is parsed into a single document corpus. The parsing process uses a text processing pipeline that includes:
- Upper- to lowercase transformation.
- Punctuation removal.
- Tokenization (breaking sentences into words).
- (English only) Lemmatization (determining basic word forms; for example, the basic form of "better" is "good").
- Stop word filtering (overly common words of the language are removed).
When all of the search result documents are parsed, the corpus represents a record of the total number of documents, the average size of each document, and the number of documents that would match a particular search term. Each document within the corpus has a record of the number of unique terms within that document, and the number of occurrences of each unique term. These values are then used to determine the relevance score of each term within the user’s search query. The user’s query is also parsed by the same pipeline to facilitate matching.