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Technical University of Crete

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Boolean search

A search argument comprises one or more terms and optional search parameters, separated by white space that you specify to search text documents. When you specify a term, the search engine returns documents that contain that term and, by default, variations on that term. For example, if you search by using the term king, documents containing king and kings are returned. If you search by using multiple terms, the search engine returns only documents containing all the terms. If you want to search by using an exact phrase, surround the phrase in quotation marks.

Fuzzy search

Use a fuzzy search to find documents that contain words with spelling similar to that of the search term. A common reason to perform a fuzzy search is to include documents that contain misspellings in the search result. A fuzzy search query searches for character sequences that are not only the same but similar to the query term. Use the tilde symbol (~) at the end of a term to do a fuzzy search.

You can also add an optional parameter to specify the degree of similarity of the search results to the search term. Specify a value greater than or equal to 0 and less than 1. The value must be preceded by a 0 and decimal point, for example, 0.8. A value closer to 1 matches terms with a higher similarity. If the parameter is not specified, the default is 0.5. Fuzzy search syntax can be specified per term, but not on a phrase. To apply fuzzy search to multiple words in a query, you must apply a fuzzy search factor for each term. Special characters are not supported in fuzzy search queries. If wildcard characters are included in the fuzzy search terms, only the wildcard search is done.

Proximity search

A proximity search retrieves documents that contain search words which are located within a specified distance from each other. To start a proximity search use the tilde (~) symbol at the end of a phrase and specify the distance in words as a valid integer number. When determining the distance consider that sentence breaks count as 10 position increments. Special characters are not supported in proximity search queries.

Searches are not case sensitive, so a search in Spanish for the exact term "DOS" might return documents containing DOS or dos. The more specific the search term that you use, the more precise the results.

However, you can also refine your searches by using options such as the following ones:

• Boolean operators

Use the AND operator to search for documents that contain all the specified terms. The AND operator is the default conjunction operator. If there is no logical operator between the two terms, AND is used. The OR operator links the two or more terms and finds a matching document if either of the terms exists in a document.

• Occurrence modifiers

Use a plus sign (+) to specify that terms are required. The plus sign (+) modifier is distinct from the AND operator because the plus sign (+) modifier indicates that the second term must be an exact match. No synonym is used. Use a minus sign (-) or the NOT modifier to specify that terms are prohibited.

• The boost modifier

Use the caret (^) character to give higher importance to occurrences of a particular term. The caret (^) character provides a boost to the term or phrase that precedes it when the specified number is greater than 1. If you want to reduce the ranking of the term or phrase in the returned list, specify a number that is greater than 0 but less than 1.

• Wildcard characters

Use a question mark (?) to specify that a single character can be added to your search term. Use an asterisk (*) to specify that any number of characters can be added to your search term. Use these wildcard characters to search terms and data for spelling variations and increase search scope.

Important: Using the asterisk (*) wildcard at the beginning of a search term negatively affects the performance of the search query.

Wildcard searches with an asterisk (*) apply a term expansion to find documents. If the number of matching terms in the text index collection exceeds the expansion limit, only a subset of documents that match the criteria is returned. Also, wildcard searches find regular characters, not special characters. For example, searching for US-*-abc finds strings such as US-xxx-abc, US-x-abc, and US-x#-abc but not US-#-abc.

• The percentage sign (%): Use a percentage sign (%) to specify that a term or phrase is optional.

• The backslash (\) escape character: Use a backslash (\) to include special characters in your search. All of the following characters are special characters in text search queries:

<,>,&&,||,!,(,),%,=,",{,},~,*,?,[,],:,\,-

• Double quotation marks ("): Use quotation marks (") around your search term or phrase to have only exact matches returned.

• Parentheses: Use parentheses to have search terms and the relationship between them treated as a single item.

Examples

Operator/Modifier	Example	Query Results
AND	King AND Lear King Lear	Returns items that contain the terms King and Lear.
OR	Hamlet OR Othello	Returns items that contain either Hamlet or Othello.
NOT -	Hamlet NOT Othello Hamlet -Othello	Returns items that contain Hamlet but not Othello.
+	Lear + King	Returns items that contain the terms Lear and King.
^	Hamlet^2 Othello Hamlet Othello^.5	Returns items containing Hamlet and Othello but gives more importance to the term Hamlet. In both example queries, each occurrence of the term Hamlet is given twice as much importance as each occurrence of Othello is given.
~	analytics~   summer~0.7 time~0.7   “summer time”~4	Returns items that include the terms analytics, analyze, analysis, and so on. Returns items that include terms that are similar to summer and time. Returns items that include the terms summer and time within 4 words of each other.
*	king* k*ng *ing	Returns items that contain possible combinations of the search term with the wildcard character. The example query might return results such as king and kingdom in the first example, king and kissing in the second example, and king and skiing in the third example.
*	www.*.com	Searching using wildcards does not return terms that contain special characters. The example query might return www.ibm.com but does not return www.#.com.
?	mea? be?n ?ean	Returns items that contain possible combinations of the search term with the wildcard character. The first example returns results such as meal and mean, the second example returns results such as bean and been, and the third example returns results such as mean and bean.
%	King James %Edition	Returns items that contain both king and james, but edition is an optional term.
"phrase" "exact term"   "phrase with wildcard"	"King Lear" "king"   "John * Kennedy" "John ? Kennedy"	Returns items that contain the exact word or phrase. The first example returns King Lear. The second example returns the word king and no other forms, such as kings or kingly. You can use quotation marks with wildcards. The first example returns occurrences of John Kennedy with or without various middle names or initials. The second example returns John initial Kennedy.
( )	(Hamlet OR Othello) AND plays	Returns items that contain the following terms: The term Hamlet or Othello The term plays
\	\(1\+1\)\:2	Returns items that contain (1+1):2. Use the backslash (\) character to escape special characters that are part of the query syntax.

Submission Guides

The Repository supports the OpenSearch API which allows other systems to perform remote searches and receive back results in XML format. The use of API is free. However, commercial use of the API is not allowed.

You can access the OpenSearch API at https://sndbx.library.tuc.gr/opensearch.
Query temrs should be provided in the form: ?q=query-terms. The provided terms will be searched over the entire set of metadata elements (title, summary, subjects, etc.) as well as within the Item files.

Query Example:

https://sndbx.library.tuc.gr/opensearch?q=Traffic Control

The Institutional Repository of TUC supports the OAI-PMH 2.0 that allows to third party systems to harvest its bibliographic metadata. The service is provided free of charge for educational, research, and in general non-commercial purposes..

Access to the OAI-PMH service is provided through the link https://sndbx.library.tuc.gr/oaiHandler.

Service Identification:

https://sndbx.library.tuc.gr/oaiHandler?verb=Identify