Magento Commerce, 2.2.x
MySQL

MySQL is the default search engine. By adjusting the Catalog Search configuration, you can control the behavior of the search operations and determine the size of valid query text and the display of search recommendations. By default, MySQL always has the EAVEntity Attribute Value Indexer enabled. This feature improves indexation speed and restricts the indexer from use by 3rd party extensions.

To configure MySQL search:

1. On the Admin sidebar, tap Stores. Then under Settings, choose Configuration.
2. In the panel on the left under Catalog, choose Catalog.
3. Expand the Catalog Search section.
4. By default, the Search Engine is set to “MySQL.” If switching to MySQL, select that option. This affects the available fields.
5. To limit the length and word count of search query text, set the Minimal Query Lengthand Maximum Query Length.

Important: The value set for this minimum and maximum range must be compatible with the corresponding range set in your MySQL search engine configurations. For example, if you set these values to 2 and 300 in Magento, update the values in your search engine.

6. To limit the amount of popular search results to cache for faster responses, set an amount for Number of top search results to cache.

The default is 100. Entering a value of 0 caches all search terms and results when entered a second time.

7. To display search suggestions, set Enable Search Suggestions to “Yes.” Additional configuration options display.
a. In the Search Suggestion Count field, enter the number of suggestions to offer for each search term that returns no results.  The default is 2.
b. To display the number of search results for each suggested term, set Show Results Count for Each Suggestion to “Yes.”
8. To offer search recommendations, set Enable Search Recommendations to “Yes.”  Additional configuration options display.
a. In the Search Recommendations Count field, enter the number of recommendations that you want to offer. The default is 5.
a. To display the number of results for each recommendation, set Show Results Count for Each Recommendation to “ Yes.”
9. When complete, tap  Save Config .