2d barcode vb.net Full-text search: a promising solution in Java

Painting Data Matrix ECC200 in Java Full-text search: a promising solution

Full-text search: a promising solution
DataMatrix Generation In Java
Using Barcode maker for Java Control to generate, create Data Matrix 2d barcode image in Java applications.
www.OnBarcode.com
Recognizing Data Matrix ECC200 In Java
Using Barcode decoder for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
to drive. Indexing is the mechanics of our search engine, and searching is the useroriented polish that will hook our customers.
Painting Linear Barcode In Java
Using Barcode encoder for Java Control to generate, create Linear 1D Barcode image in Java applications.
www.OnBarcode.com
Universal Product Code Version A Creation In Java
Using Barcode encoder for Java Control to generate, create UPC-A Supplement 5 image in Java applications.
www.OnBarcode.com
Searching
GS1 DataBar Expanded Maker In Java
Using Barcode generator for Java Control to generate, create GS1 RSS image in Java applications.
www.OnBarcode.com
PDF-417 2d Barcode Creation In Java
Using Barcode generation for Java Control to generate, create PDF417 image in Java applications.
www.OnBarcode.com
If we were using SQL as our search engine, we would have to write a lot of the searching logic by hand. Not only would it be reinventing the wheel, but very likely our wheel would look more like a square than a circle. Searching takes a query from a user and returns the list of matching results efficiently and ordered by relevance. Like indexing, searching is a multistep process, as shown in figure 1.7. We ll walk through the steps and see how they solve the problems we ve seen during the development of our SQL-based search engine. The first operation is about building the query. Depending on the fulltext search tool, the way to express query is either:
GTIN - 128 Maker In Java
Using Barcode printer for Java Control to generate, create EAN / UCC - 13 image in Java applications.
www.OnBarcode.com
Encode UPC Case Code In Java
Using Barcode drawer for Java Control to generate, create UPC Case Code image in Java applications.
www.OnBarcode.com
String based A text-based query language. Depending on the focus, such a language can be as simple as handling words and as Figure 1.7 Searching process. From a user or program request, determine the list of words, find the complex as having Boolean appropriate documents matching those words, operators, approximation oper- eliminate the documents not matching, and order the ators, field restriction, and results by relevance. much more! Programmatic API based For advanced and tightly controlled queries a programmatic API is very neat. It gives the developer a flexible way to express complex queries and decide how to expose the query flexibility to users (it might be a service exposed through a Representational State Transfer (REST) interface).
Scan Data Matrix ECC200 In C#.NET
Using Barcode recognizer for VS .NET Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
Encode Data Matrix 2d Barcode In Objective-C
Using Barcode printer for iPad Control to generate, create ECC200 image in iPad applications.
www.OnBarcode.com
Some tools will focus on the string-based query, some on the programmatic API, and some on both. Because the query language or API is focused on full-text search, it ends up being much simpler (in complexity) to write than its SQL equivalent and helps to reduce one of the problems we had with our SQL-based search engine: complexity. The second operation, let s call it analyzing, is responsible for taking sentences or lists of words and applying the similar operation performed at indexing time (chunk
Draw UPC Code In None
Using Barcode printer for Word Control to generate, create UPC-A Supplement 5 image in Word applications.
www.OnBarcode.com
DataMatrix Encoder In None
Using Barcode drawer for Word Control to generate, create Data Matrix ECC200 image in Office Word applications.
www.OnBarcode.com
State of the art
Barcode Scanner In .NET
Using Barcode Control SDK for ASP.NET Control to generate, create, read, scan barcode image in ASP.NET applications.
www.OnBarcode.com
Encoding EAN-13 Supplement 5 In None
Using Barcode generator for Online Control to generate, create European Article Number 13 image in Online applications.
www.OnBarcode.com
into words, stems, or phonetic description). This is critical because the result of this operation is the common language that indexing and searching use to talk to each other and happens to be the one stored in the index. If the same set of operations is not applied, the search won t find the indexed words not so useful! This common language is the cornerstone of full-text search performances (another problem we had with our SQL-based search engine). Based on the common language between indexing and searching, the third operation (finding documents) will read the index and retrieve the index information associated with each matching word (see figure 1.8). Remember, for each word, the index could store the list of matching documents, the frequency, the word positions in a document, and so on. The implicit deal here is that the document itself is not loaded, and that s one of the reasons why full-text search is efficient: The document does not have to be loaded to know whether it matches or not. The next operation (filtering and ordering) will process the information retrieved from the index and build the list of documents (or more precisely, handlers to documents). From the information available (matching documents per word, word frequency, and word position), the search engine is able to exclude documents from the matching list. More important, it is able to compute a score for each document. The higher its score, the higher a document will be in the result list. A lengthy discussion about scoring is available in chapter 12, but in the meantime let s have a look at some factors influencing its value:
Code 128C Maker In .NET
Using Barcode printer for ASP.NET Control to generate, create Code 128 Code Set B image in ASP.NET applications.
www.OnBarcode.com
Draw Code 39 Full ASCII In .NET
Using Barcode generator for Reporting Service Control to generate, create Code-39 image in Reporting Service applications.
www.OnBarcode.com
In a query involving multiple words, the closer they are in a document, the higher the rank. In a query involving multiple words, the more are found in a single document, the higher the rank. The higher the frequency of a matching word in a document, the higher the rank. The less approximate a word, the higher the rank.
Printing GS1-128 In .NET
Using Barcode creation for .NET framework Control to generate, create EAN 128 image in Visual Studio .NET applications.
www.OnBarcode.com
Barcode Encoder In C#.NET
Using Barcode encoder for VS .NET Control to generate, create Barcode image in Visual Studio .NET applications.
www.OnBarcode.com
Depending on how the query is expressed and how the product computes score, these rules may or may not apply. This list is here to give you a feeling of what may affect the score, therefore the relevance of a document. This last part has solved the final problem faced by our SQL-based search engine: ordering results by relevance. Once the ordered list of documents is ready, the full-text search engine exposes the results to the user. It can be through a programmatic API or through a web page. Figure 1.8 shows a result page from the Google search engine. Sounds like we ve found the perfect solution to address our problem. Now let s have a look at the kind of full-text search solutions on the market.
DataMatrix Maker In .NET Framework
Using Barcode creation for ASP.NET Control to generate, create Data Matrix ECC200 image in ASP.NET applications.
www.OnBarcode.com
Barcode Drawer In Java
Using Barcode printer for Android Control to generate, create Barcode image in Android applications.
www.OnBarcode.com
Copyright © OnBarcode.com . All rights reserved.