Symptoms
Text searches for small words or acronyms like asm, ats, ins etc.. do not return the expected results.
This message is displayed: Your text query contained only common words or ambiguous wildcards, please refine your search and try again
If you debug Text Search you will see TSFalseQueryTerm
Release
ALL
Cause
We consider some smaller words to be stemmed from stop words. For instance, we treat "ams" as "am" when we search for it because we are cutting off the trailing "s".
You can check the stems of words using an online site which uses the same Porter stemming algorithm we do such as this one.
https://s2.smu.edu/~fmoore/misc/porter_stemmer_example.html
Resolution
Here are the steps you can take to remove a stop word so we will no longer block results for it.
WARNING: This can impact the performance of search and cause results for the stem so we do not recommend doing it.
1) Navigate to System Definition > Text Index Stop Words and find the record for the stem and uncheck the active flag.
2) Go through any table text indexes ( System Definition > Text Indexes ) which may contain the stem as a stop word. Start with task, kb_knowledge, and sys_metadata as well as any others you expect to have the term in.
3) If you find any records in here, you can open them and set the Stop Mode to be Not a Stop Word.
4) Lastly, you will probably need to regenerate the text index for any tables which you want to search for AMS because we would not have been indexing before since it was always a stop word.
Additional Information
Here is documentation on how to regenerate the text index for a table.
https://docs.servicenow.com/bundle/kingston-platform-administration/page/administer/search-administration/task/t_RegenerateATextIndexForATable.html
Here is our documentation on stemming.