Search Features
Overview
Fess provides powerful full-text search capabilities. This section explains detailed configuration and usage of search features.
Search Result Count Display
Default Behavior
When search results exceed 10,000 items, the search results screen displays “Approximately 10,000 or more results.” This is the default setting considering OpenSearch performance.
Search Example
Displaying Accurate Hit Counts
To display accurate hit counts for more than 10,000 items, change the following setting in fess_config.properties.
query.track.total.hits=100000
This setting allows you to retrieve accurate hit counts up to 100,000 items. However, setting too large a value may impact performance.
Warning
Setting the value too high may degrade search performance. Set an appropriate value based on actual usage.
Search Options
Basic Search
In Fess, simply entering keywords in the search box executes a full-text search. Entering multiple keywords executes an AND search.
search engine
The above example searches for documents containing both “search” and “engine”.
OR Search
To execute an OR search, insert OR between keywords.
search OR engine
NOT Search
To exclude specific keywords, prefix the keyword with - (minus sign).
search -engine
Phrase Search
To search for an exact phrase, enclose it in double quotes.
"search engine"
Field-Specific Search
You can search by specifying specific fields.
title:search engine
url:https://fess.codelibs.org/
Main fields:
title: Document titlecontent: Document bodyurl: Document URLfiletype: File type (e.g., pdf, html, doc)label: Label (classification)
Wildcard Search
Wildcard searches are available.
*: Any string of zero or more characters?: Any single character
search*
se?rch
Fuzzy Search
Fuzzy search for spelling mistakes and notation variations is available. By default, fuzzy search is automatically applied to keywords of 4 or more characters.
search~
You can specify edit distance by adding a number after ~.
Search Result Sorting
Search results are sorted by relevance by default. You can specify the following sort orders via administration screen settings or API parameters:
Relevance order (default)
Last modified date order
Creation date order
File size order
Faceted Search
Faceted search allows you to narrow down search results by category. By default, the label field is configured as a facet.
You can narrow down search results by clicking facets displayed on the left side of the search screen.
Search Result Highlighting
Search keywords are highlighted in the title and summary sections of search results. Highlight settings can be customized in fess_config.properties.
query.highlight.tag.pre=<strong>
query.highlight.tag.post=</strong>
query.highlight.fragment.size=60
query.highlight.number.of.fragments=2
Suggest Feature
When entering text in the search box, suggestions (autocomplete) are displayed. Suggestions are generated based on past search keywords and popular search keywords.
The suggest feature can be enabled/disabled in the “General” settings on the administration screen.
Search Logs
Fess records all search queries and click logs. These logs can be used for:
Analyzing and improving search quality
Analyzing user behavior
Understanding popular search keywords
Identifying keywords with zero search results
Search logs are stored in OpenSearch’s fess_log index and can be visualized and analyzed in OpenSearch Dashboards. See Search Log Visualization Configuration for details.
Performance Tuning
Search Timeout Configuration
You can configure search timeout duration. The default is 10 seconds.
query.timeout=10000
Maximum Query Length
For security and performance, you can limit the maximum query length.
query.max.length=1000
Using Cache
By enabling search result caching, you can reduce response time for the same search queries. Adjust cache settings according to system requirements.
Troubleshooting
No Search Results Displayed
Verify that the index is created correctly.
Verify that crawling completed successfully.
Verify that access permissions are not set on search target documents.
Verify that OpenSearch is operating normally.
Slow Search Speed
Check OpenSearch heap memory size.
Optimize index shard count and replica count.
Check search query complexity.
Check hardware resources (CPU, memory, disk I/O).
Irrelevant Results Displayed
Adjust boost settings (
query.boost.title,query.boost.content, etc.).Review fuzzy search settings.
Check Analyzer configuration.
If necessary, consult commercial support.