(C) IBM Corp. 2000
DB2 Net Search Extender Administration and User's Guide
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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