Query Languages

1
Query Languages
2
Keyword-Based Querying

• Single Word Queries
• Context Queries
• Phrase
• Proximity
• Boolean Queries
• OR, AND, BUT
• Natural Language

3
Pattern Matching

• allow the retrieval of pieces of text that have
  some property (match a pattern).
• Pattern is a set of syntactic features that must
  occur in a text segment
• Words
• Prefixes
• Suffixes
• Substrings
• Ranges
• Allowing errors (note edit distance)
• Regular expressions
• Union ab Concatenation ab repetition a
• Example (DNA microbe) (question problem) (?
  s)

4
Structural queries

• Form-like fixed structure
• Given example Mail archive
• Other examples Log file,
• Hypertext structure
• Search by content and structure
• Hierarchical structure
• Intermediate level of flexibility

5
Hierarchical models

• PAT expressions
• PAT is a text searching system
• Developed at University of Waterloo
• Commercially available through Open Text
  Corporation in Waterloo
• See PAT expressions an algebra for text search
• By Airi Salminen and Frank W. Tompa
• Acta Linguistica Hungarica 41, 1-4 (1992-93)
  1994, 277-306
• http//db.uwaterloo.ca/fwtompa/publications.html
• http//db.uwaterloo.ca/OED/search/expl-pat.html
• Match a string and return the string and suffix,
  to the end of the document.

6

• PAT interprets text as a set of suffix strings
• For example, indexing every word in this sentence
  yields the 12 strings
• For example, indexing every word in this sentence
  yields the 12 strings
• example, indexing every word in this sentence
  yields the 12 strings
• indexing every word in this sentence yields the
  12 strings
• every word in this sentence yields the 12
  strings
• word in this sentence yields the 12 strings
• in this sentence yields the 12 strings
• this sentence yields the 12 strings
• sentence yields the 12 strings
• yields the 12 strings
• the 12 strings
• 12 strings
• strings

7
PAT search example

• gtgt water
• 1 48442 matches
• gtgt pr sample.7
• 192807323, ..sper.dr-lt/gkgt water
  ltgkgtalenis.dhfaacu.gojlt/gkgt voracious s..
• 520790341, ..e took to the water, disappeared,
  leaving it on the low under ba..
• 145798504, ..nced from the water like a carp.
  lt/Tgtlt/QgtltQgtltDgt1843lt/Dgt ltAgtPaget..
• 549737948, ..4 ltTgtThe 1929 water ski champion,
  Herr Pribitzer of the water-sk..
• 190797617, ..ngsleylt/Agt ltWgtWater-Bab.lt/Wgt iii.
  116 ltTgtDark hovers under swirl..
• 549099801, ..ating-oil..of water-white and
  odorless qualities. lt/Tgtlt/QgtltQgtltDgt..
• 549623784, .. the maddest Waterloo-Crackers.
  lt/Tgtlt/QgtltQgtltDgt1851lt/Dgt ltAgtMayhe..
• Source http//db.uwaterloo.ca/OED/search/expl-pat
  .html

8

• gtgt a..z
• 2 60343111 matches
• gtgt pr sample
• 555709177, ..e Christopher as my owne, I will he
  be put unto the schoale. lt/T..
• 290164101, ..ir slangy off-colour jokes.
  lt/Tgtlt/QgtltQgtltDgt1972lt/Dgt ltPSAgtltAgtG. Bl..
• 10053096, ../Dgt ltWgtCompl. Fam.-Piecelt/Wgt ltscgtii.
  lt/scgtiii. 388 ltTgtAmber Pear..
• 97073359, ..gt in ltWgtCott. Hom.lt/Wgt 201 ltTgtTh.e
  muchele delit of th.ine swe..
• 58277014, .. specially in knowledge (as the
  seraphim in love) a conventiona..
• 194517420, ..mplative, and nonverbal.
  lt/Tgtlt/Qgtlt/PQPgtltPQPgtltQgtltDgt1957lt/Dgt ltWgtWh..
• 408029625, ..us widths and patterns.lt/Tgtlt/QgtltQgtltDgt
  1833lt/Dgt ltAgtJ. Bennettlt/Agt ..
• 481205743, ..design of the SEAC and DYSEAC.
  lt/Tgtlt/QgtltQgtltDgt1960lt/Dgt ltAgtGregory..
• 440450458, ..III. 558/2 ltTgtThe domain of Sonata
  was for a long while almost m..
• 502535403, ..ed comprises..two Gatling guns, and
  six torpedo tubes or torped..

9

• gtgt "to be or"
• 3 458 matches
• gtgt pr sample.5
• 454233240, .. set upright to be or become erect.
  Of hair, spines, etc. cf...
• 562398537, ..lt/PSgt, liable to be or capable of
  being withheld.lt/DEFgtlt/SEgtlt/pgt..
• 94031003, ..gtlt/ILgt) i.e. to be (or make it) a
  matter of death of capital pu..
• 192510576, ..Of the voice to be or to become
  husky. lt/pgtlt/DEFgtltQPgtltQgtltDgt1922..
• 407435097, ..7 ltTgtA Sealer to be ordeyned amp.
  sworne to stryke the Cloth a..

10
Query Protocols

• Z39.50
• WAIS
• CCL
• CD-RDx
• SFQL