Support for the Contains Operator of Each Source Type¶
The syntax of the search language on non-structured data used with the
contains operator is described in the section Syntax of Search Expressions for the Contains Operator. However, bear in mind that the
search options available depend on the capacities natively provided by
the data source. For example, Google Search does not support different
characteristics of the search language such as proximity searches.
Therefore, when the contains operator is used with attributes from
those sources, these capacities will not be available.
This section provides exact details as to the search capacities
supported for each source type. These capacities are also specified in
the Configuration Properties of each data source (see section CONTAINS Operator Configuration Properties) that can be consulted using the
DESC VIEW statement (see section Describing Catalog Elements).
The data sources Aracne-type (see section Denodo Aracne Data Sources), Google Search (see Google Search Data Sources) and Custom
(see Custom Data Sources) can use the contains operator.
The following sections describe the capacities supported for Aracne and Google Search wrappers, respectively. Custom-type wrappers can specify the capacities supported through the Configuration Properties (see section CONTAINS Operator Configuration Properties and section Describing Catalog Elements).
Aracne¶
The following characteristics of the contains operator search
language are not supported in Denodo Aracne-type sources:
The wildcards
?and*cannot appear in the first position of a term.Searches using the proximity operator
~must specify the maximum number of words that can separate the terms of the phrase.The logic operator
NOTmust appear at the same level as a logic operatorAND. Example: The search(term1 AND NOT term2)would work correctly, but not the search(term1 OR NOT term2).
The remaining capacities of the search language are supported in Denodo Aracne-type sources.
Google Search¶
The following characteristics of the contains operator search
language are not supported in Google Search sources:
Searches by exact phrase are not supported in the
siteattribute. They are supported, however, in the remaining attributes.Wildcards, fuzzy searches, proximity searches, searches with relevance boost and range searches are not supported.
Searches with the logic operators
AND,OR, andNOTin thetitle,url, andsiteattributes are only valid if the conditions are simple terms or exact phrases (i.e. logic conditions cannot be nested in searches on these attributes). This restriction does not exist for the remaining attributes.The logic operator
NOTmust appear at the same level as a logic operatorAND. Example: The search(term1 AND NOT term2)would work correctly, but not the search(term1 OR NOT term2).