Download
full text search n.
Skip this Video
Loading SlideShow in 5 Seconds..
Full Text Search PowerPoint Presentation
Download Presentation
Full Text Search

Full Text Search

118 Vues Download Presentation
Télécharger la présentation

Full Text Search

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Full Text Search

  2. Some Info • An optional component • Much faster and complex than the previous version • Allow you to search for words and tokens in binary, char, nchar, varchar, nvarchar. XML, image, text, and varbinary • It build indexes on these columns • Select * from Authors where contains(bio, ‘Oregon’); Not • Select * from Authors where bio like ‘%Oregon%’

  3. Comparing with Like • Full-text search • Is magnitude faster • Can search other data types than text • Can use language features such as searching for ‘take’ gives you ‘took’, takes, and taken as well • However, like can • Search middle of a word,  like ‘&puter’ • Search for sequence  like ‘ab[c,d][1-9]%’ • Faster than full text search with nonclustered index, if you search the entire column or beginning of the column

  4. Few new features • 48 languages • Noise lists, or Stop Words, (of, the, a etc.) • Failover support on mirrored database • Dynamic Management View supports troubleshoot • … …(see page 204)

  5. Architecture • Three key elements • Indexing • Searching • Filter • The column is index per words in the column, not the entire content of a record’s column • Searching uses the indexes • A filter is used if the column is not texted • For example, a XML filter is used for XML data, a MS Word filter is used for MS Word data, etc

  6. Word Breaker • A tool determine how to break words from sentences • For example, FBI will match with F.B.I, but not for fbi. • For example, UK word breaker will understand realise, realising, and realised; while the US breaker will understand realize, realizing, and realized

  7. Search • Contains – more exact matches • FreeText – matches other forms mouse + mice • ContainsTable/FreeTextTable – returns results for ranking • Contains can be more powerful combining with FormsOf, Near, boolean operations, weighted, or * (a wildcard operator)

  8. Hands on • First create the category • Then create indexes • Use the wizards