Zing index and search dictionary attributes
-
- UpdatedJan 30, 2025
- 4 minutes to read
- Yokohama
- Search Administration
The following dictionary attributes either affect the way Zing indexes tables or ranks search results.
Index and search dictionary attributes
- indexing behavior
- ranking of search results
- the BM25 relevancy ranking algorithm
no_text_index
For Customer Service and Support guidelines on setting the no_text_index option for different field types, see KB0859922 on the Now Support site.
text_index_scorer_bm25_b
This dictionary attribute is part of the BM25 algorithm. The attribute impacts the importance of the length of a document in search results. If this attribute is 0, the length has no bearing. In this case, a document of two words would be valued equally as a document with 1000 words. Very short documents are often weighted lower than longer documents. The default is 0.75.
text_index_scorer_bm25_k1
This dictionary attribute is part of the BM25 algorithm. The attribute helps determine term frequency saturation characteristics, that is, having the search term appear in a document increases the relevancy of the document, but the increase is less impactful as the numbers climb. For example, a search term occurring 10 times in a document makes it more relevant than a document that has only one occurrence. However, a document that has 100 occurrences of the search term may not be ten times more impactful than a document that has 10 occurrences. The relevance approaches a maximum effect asymptote. The higher the attribute value, the lower the maximum effect of multiple occurrences. Typical values are between 1.25 - 2.0.
On this page
Related Content
- Zing indexes punctuation as part of some words
Zing indexes some punctuation marks as part of some words to improve search results for common search terms.
- Zing indexes some HTML elements
Zing indexes the contents of certain HTML elements to improve document search results. This indexing is addition to the normal indexing by word.
- Configure a table for indexing and searching
Enable Zing text indexing for a table to allow users to search its records for string values. Configure the table's text indexing attributes, stop words, and synonym dictionaries to control search behavior.
- Configure a text index group to search across multiple tables
Update tables to the V4 indexing format and include them in a text index group to facilitate searching across multiple tables.
- Regenerate a text index for a table
You can regenerate a table text index when you change table stop words or display values.
- Remove an index
You can remove the index for a table if you no longer want the search engine to return results for that table. This procedure also removes the index for all tables that extend the specified table.
- Remove an index for a specific field
You can remove the index for a specific field in a table if you no longer want the search engine to return results for that field.
- Remove the text index for a child table
You can remove the text index for a child table if you no longer want the search engine to return results for that child table.
- Change the query mode of an indexed table
Set the query mode to specify whether searches on an indexed table must match all or only some of the search terms.
- Enable indexing of text in multi-row variable sets
Make text from multi-row Service Catalog variable sets searchable in global search.
- Text indexing statistics and status
To view text indexing statistics and status, navigate to All System Definition Text Indexes .
- Configure tables to use the Japanese tokenizer
Improve search results in Japanese language searches by configuring individual tables to use the Japanese tokenizer.