(C) IBM Corp. 1996, 1999
Text Extender: Administration and Programming
This command changes the default settings of the text configuration that is
used when a database is enabled. These are the text
configuration settings. The initial text configuration settings
when Text Extender is installed are described in Text configuration settings.
To change these settings for a particular database after the
database has been enabled, use CHANGE INDEX SETTINGS.
Authorization
You must have:
SYSADM authority
DBADM authority.
Command syntax
>>-CHANGE TEXT--+-CONFIGURATION-+---USING----------------------->
'-CFG-----------'
>-----+-----------------------+--------------------------------->
'-| text-information |--'
>-----+---------------------------------------------------------------+>
'-INDEXTYPE--+-PRECISE----+---+------------------------------+--'
+-LINGUISTIC-+ '-TABLESPACE--tablespace-name--'
+-DUAL-------+
'-NGRAM------'
>-----+----------------------------------------+---------------->
'-UPDATEFREQ--+-NONE------------------+--'
'-| update-frequency |--'
>-----+-----------------------+--------------------------------->
'-DIRECTORY--directory--'
>-----+----------------------------+---+---------------------+-><
'-UPDATEINDEX--+-UPDATE---+--' '-COMMITCOUNT--count--'
'-NOUPDATE-'
text-information
|---+---------------+---+---------------------+----------------->
'-CCSID--ccsid--' '-LANGUAGE--language--'
>-----+-----------------+---------------------------------------|
'-FORMAT--format--'
update-frequency
|---MIN--(--mindocs--)--D---(--+-*------------+---)---H--------->
| .-,-------. |
| V | |
'----0...6---+-'
.-,---------.
V |
>----(--+-*-------------+---)---M---(-----0...59---+---)--------|
| .-,--------. |
| V | |
'----0...23---+-'
Command parameters
- INDEXTYPE
- To change the default index type, choose one of the following. For
more information, see Types of index.
- PRECISE
- Terms are indexed and searched for exactly as they occur in the text
documents.
- LINGUISTIC
- Terms are processed linguistically before being indexed. Search
terms are also processed linguistically before the search begins.
- DUAL
- Terms are indexed exactly as they occur in the text documents, and they
are also indexed after being processed linguistically. When searching,
you can decide for each term whether to search for the precise term or for the
linguistically processed term.
- NGRAM
- Terms are indexed by parsing sets of characters rather than by using a
dictionary. This dictionary type is mandatory if the documents you are
indexing contain DBCS characters, although an Ngram index can also be used for
SBCS documents.
- TABLESPACE tablespace-name
- Specify the name of an existing tablespace. The tablespace is used
to hold the index-specific administration tables created by Text Extender
(like the log tables). For large tables, use a separate
tablespace. If you do not specify a tablespace, the tables are created
in the DB2 default tablespace.
- UPDATEFREQ
update-frequency
- The index update frequency in terms of when the update is to be made, and
the minimum number of text documents that must be queued in the log
table. If there are not enough text documents in the log table at the
day and time given, the index is not updated.
The syntax is described in Setting the frequency of index updates.
- NONE
- No further index updates are made. This is intended for a text
column in which there will be no further changes.
- DIRECTORY
directory
- The directory in which the text index is to be stored.
- UPDATEINDEX
- A keyword that determines whether the text documents are indexed
immediately after the command using this option has completed, without waiting
for the next periodic indexing set by UPDATEFREQ. These commands are
ENABLE TEXT COLUMN, and ENABLE TEXT FILES.
- UPDATE
- Indexing of the text documents occurs immediately after the command has
completed.
- NOUPDATE
- Indexing occurs at a time set by the update frequency settings specified
either in this command by UPDATEFREQ, or by the text configuration
setting.
- COMMITCOUNT
count
- A value from 500 to 1000000 indicating the number of inserts or updates
after which a DB2 UDB intermediate commit statement is issued. This can
avoid a situation in which there is insufficient log space when enabling large
tables, or columns, or a large number of external files.
- CCSID
ccsid
- The Coded Character Set Identifier to be used when indexing text
documents.
For information about CCSIDs that can be supported, see CCSIDs.
- LANGUAGE
language
- The language in which the text is written. This determines which
dictionary is to be used when indexing text documents and when searching in
text documents. Chapter 3, Linguistic processing describes how dictionaries are used.
The supported languages are listed in Languages.
- FORMAT
format
- The type of text document stored, such as WordPerfect, or ASCII.
Text Extender needs this information when indexing documents. The
document formats supported are listed in Formats.
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