New to Omeka 2.0 is a Settings section dedicated to search functionality. It's important to note that the new site-wide search encompasses all record types in Omeka (items, files, collections, as well as Simple Pages and Exhibit content), and can be constrained to particular types.
The search capability has expanded to include three options for admin and public queries:
- Keyword: similar to Google Search, a keyword search returns results ordered by relevance. Searching on "ancient warfare" will prioritize records that contain the full string "ancient warfare", but will also include records that contain the individual words "ancient" or "warfare".
- Boolean: allows greater fine-tuning than keyword search but does not return results by relevance. Do this by using certain characters at the beginning or end of words in the search string. Some examples:
- +: a leading plus sign indicates that this word must be present in each row that is returned.
- -: a leading minus sign indicates that this word must not be present in any of the rows that are returned.
- *: an appended asterisk serves as the truncation (or wildcard) operator. Words match if they begin with the word preceding the * operator.
- ": a phrase that is enclosed within double quote characters matches only rows that contain the phrase literally, as it was typed.
- More special characters and further information about boolean search can be found on the MySQL website.
- Exact match: returns records that contain at least one match to the order of words entered, like "Civil War". Use this search type if you need to search short words, like "war", and the keyword/boolean searches do not produce results.
Select Record Types
As an Omeka site Super administrator, you may choose which Omeka record types you wish to be searchable: items, collections, files. Additionally, if you installed the Simple Pages and Exhibit Builder plugins you may make that content available as well. Other plugins may make their content available for searching as well.
Using the checkboxes found to the left of each record type, choose which ones you want discoverable by the site-wide search. Please note that the "Exhibit" record type includes exhibit descriptive information, and an "Exhibit Page" is the actual content of the exhibit.
Click Save Changes.
Once records types are selected, searchers may choose from the options you have provided them, in admin and public site-wide searches.
Indexing means to collect, parse, and store data to facilitate fast and accurate searches. Omeka will automatically index individual records as they are created and saved. Re-indexing is necessary when updating from an earlier version of Omeka or after you customize which records will be searchable.
Click on the "Index Records" button to re-index your records.
If you are having trouble finding by search words you know are in your install, the following may be part of the problem:
- MySQL by default does not index any words shorter than 4 letters long.
- Exact match searches will look for the exact string given by the user, anywhere in the record. For example a search for 'poe' would also return 'poem'.
- MySQL considers terms that appear in over 50% of indexed items to be so common that it excludes them from keyword searches. The easy way to tell if a term meets the the 50% threshold that's at fault is to choose the "boolean" search, as MySQL does not apply the 50% limitation to boolean searches