HP StorageWorks Reference Information Storage System V1.4 User Guide (T3559-96028, December 2005)
6 Que ry exp res sion syntax and
matching
Query expression syntax and matching describes the syntax to use to search and retrieve archived
documents (files or email messages), and explains how queries are matched against documents.
Major topics include:
•Queryexpressions, page 71
•Wordcharacters,page71
•
Letters and digits in different character sets , page 72
•
Matching words, page 73
•
Matching similar words,page74
•
Matching word sequences, page 74
•Booleanqueryexpressions,page75
•
Nested Boolean q uery expressions,page76
•
Query expression examples,page76
Query expressions
Query exp
ressions can be as simple or as complex as needed. The essential idea behind document
retrieval is that query words are compared with document words to find a match. You can also:
• Look for document words that are textually similar, but not necessarily identical, to query words.
See "Mat
ching similar words" on page 74.
• Look for word sequences in a document: words that are near each other, and in a particular
order. See "Matching word sequences" on page 74.
• Combin
e query words using logical (Boolean) operators (AND, OR, NOT). See "Boolean query
expressions" on page 75.
Together, these query constructs provide considerable power to find what you need, provided you
learn to use them well.
The way
query expressions are interpreted is similar to the way documents are indexed when archived.
Text is parsed (broken d own) into words. Remaining characters are considered separators and ignored.
Quer y expressions are fundamentally comp osed of words, no matter how complex the expression.
For indexing and searching, a word need not belong to a natural language, such as English. For
examp
le, wt6_ht3 is a valid document word or quer y word. Query words can contain wildcards,
such as in f??t.
Word characters
When the system examines a query expression to determine its words, some characters a re not included
in query words, but are treated as word separators. When a document is archived, indexing determines
which document words are available for searching in the same way.
Learning the rules of creating query words means also learning the rules of document indexing and,
therefore, what words you can search for.
Reference Information Storage System User Guide
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