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DB2 Net Search Extender Administration and User's Guide


Glossary

This glossary defines terms and abbreviations used in this manual. If you do not find the term you are looking for, refer to the index or to the Dictionary of Computing, New York: McGraw-Hill, 1994.

A

access function
A user-provided function that converts the data type of text stored in a column to a type that can be processed by DB2 Net Search Extender.

B

Boolean search
A search in which one or more search terms are combined using Boolean operators.

C

catalog view
A view of a system table created by DB2 Net Search Extender Text for administration purposes. A catalog view contains information about the tables and columns that have been enabled for use by DB2 Net Search Extender Text.

CCSID
Coded Character Set Identifier.

code page
An assignment of graphic characters and control function meanings to all code points. For example, assignment of characters and meanings to 256 code points for an 8-bit code.

command line processor
A program called db2text that:

Allows you to enter DB2 Net Search Extender commands

Processes the commands

Displays the result

count
A keyword used to specify the number of levels (the depth) of terms in the thesaurus that are to be used to expand the search term for the given relation.

D

DBCS
Double-byte character set.

disable
To restore a database to its condition before it was enabled for DB2 Net Search Extender Text by removing the items created during the enabling process.

document
See text document.

document model
The definition of the structure of a document in terms of the sections that it contains. A document model makes DB2 Net Search Extender aware of the sections within documents when indexing. A document model lists the markup tags that identify the sections. For each tag you can specify a descriptive section name for use in queries against that section. You can specify one or more document models in a document models file.

E

enable
To prepare a database for use by DB2 Net Search Extender.

escape character
A character indicating that the subsequent character is not to be interpreted as a masking character.

expand
The action of adding to a search term additional terms derived from a thesaurus.

F

format
The type of a document, such as ASCII, or HTML.

free-text search
A search in which the search term is expressed as free-form text - a phrase or a sentence describing in natural language the subject to be searched for.

function
See access function.

fuzzy search
A search that can find words whose spelling is similar to that of the search term.

H

hybrid search
A combined Boolean search and free-text search.

I

index
To extract significant terms from text, and store them in a text index.

index characteristics
Properties of a text index determining:

The frequency with which the index is updated

When the first index update is to occur

L

log table
A table created by DB2 Net Search Extender containing information about which text documents are to be indexed. Triggers are used to store this information in a log table whenever a document in an enabled text column is added, changed, or deleted.

M

masking character
A character used to represent optional characters at the front, middle, and end of a search term. Masking characters are normally used for finding variations of a term in a precise index.

match
The occurrence of a search term in a text document.

P

periodic indexing
Indexing at predetermined time intervals, expressed in terms of the day, hour, and minute, and the minimum number of documents names that must be listed in the log table for indexing, before indexing can take place.

R

retrieve
To find a text document using a search argument in one of DB2 Net Search Extender's search functions.

S

SBCS
Single-byte character set.

Score
An absolute value of type DOUBLE between 0 and 1 that indicates how well a document meets the search criteria relative to the other found documents. The value indicates the number of matches found in the document in relation to the document's size.

search argument
The conditions specified when making a search, consisting of one or several search terms, and search parameters.

T

text column
A column containing text documents.

text document
Text of type CHAR, GRAPHIC, VARGRAPHIC, LONG VARGRAPHIC, DBCLOB, VARCHAR, LONG VARCHAR, or CLOB datatypes, stored in a DB2 table.

text index
A collection of significant terms extracted from text documents. Each term is associated with the document from which it was extracted. A significant improvement in search time is achieved by searching in the index rather than in the documents themselves.

tracing
The action of storing information in a file that can later be used in finding the cause of an error.

trigger
A mechanism that automatically adds information about documents that need to be indexed to a log table whenever a document is added, changed, or deleted from a text column.

U

UDF
User-defined function.

UDT
User-defined type.

update frequency
The frequency with which a text index is updated, expressed in terms of the day, hour, and minute, and the minimum number of document names that must be listed in the log table for indexing, before indexing can take place.

user-defined type (UDT)
A data type created by a user of DB2, in contrast to a data type provided by DB2 such as LONG VARCHAR.

user-defined function (UDF)
An SQL function created by a user of DB2, in contrast to an SQL function provided by DB2.

W

wildcard character
See masking character.


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