-------------------------------------------------------------------------
Oracle8 ConText Cartridge
Release 2.3 (Version 2.3.6)
RELEASE NOTES
December 1997
-------------------------------------------------------------------------
Copyright (C) 1997 Oracle Corporation
Primary Author: D. Yitzik Brenman
Contributors: Peter Bell, Chung-Ho Chen, Paul
Dixon
This software/documentation contains proprietary information of Oracle
Corporation; it is provided under a license agreement containing
restrictions on use and disclosure and is also protected by copyright
law. Reverse engineering of the software is prohibited.
If this software/documentation is delivered to a U.S. Government Agency
of the Department of Defense, then it is delivered with Restricted Rights
and the following legend is applicable:
RESTRICTED RIGHTS LEGEND:
Use, duplication, or disclosure by the Government is subject to restrictions
as set forth in subparagraph (c)(1)(ii) of DFARS 252.227-7013, Rights in
Technical Data and Computer Software (October 1988).
If this software/documentation is delivered to a U.S. Government Agency
not within the Department of Defense, then it is delivered with
"Restricted Rights," as defined in FAR 52.227-14, Rights in Data -
General, including Alternate III (June 1987).
Oracle Corporation, 500 Oracle Parkway, Redwood City,
CA 94065.
The information in this document is subject to change without notice.
If you find any problems in the documentation, please report them to us in
writing. Oracle Corporation does not warrant that
this document is error free.
Oracle, ConText, SQL*Loader, SQL*Net, and SQL*Plus are registered trademarks
of Oracle Corporation. Oracle8, PL/SQL, and Gist are trademarks of
Oracle Corporation.
All trade names referenced are the service mark, trademark, or registered
trademark of the respective manufacturer.
----------------------------------------------------------------------------
**** NOTE ****
With each distribution, ConText provides a workbench consisting of tools and
utilties which enable:
-- easy, GUI administration of ConText from a client machine or a World Wide
Web-environment
-- powerful and flexible development of ConText applications for Windows NT,
Windows 95, Oracle Forms, or the World Wide Web
The ConText Workbench can be installed on any IBM-compatible personal computer
running Windows NT or Windows 95. The Web-based administration and
application development components can be used with either Oracle WebServer
2.1 or Oracle Web Application Server 3.0.
For more information, see the Release Notes provided with the ConText
Workbench or the "Oracle8 ConText Cartridge
Workbench User's Guide".
----------------------------------------------------------------------------
TABLE OF CONTENTS
=================
INTRODUCTION
0.1 Purpose of this README
0.2 Cover Letter and Licensing
0.3 Oracle8 ConText Cartridge Documentation Currently
Available
CHANGES TO CONTEXT OPTION
1.1 New Scoring Method for Text Queries
1.2 Processing of Stopwords in Text Queries Enhanced
1.3 Changes to ctxload Parameters
1.4 New Arguments for PL/SQL Stored Procedures and Functions
1.5 Supplied External Filters Installed/Upgraded with ConText
1.6 Enhanced Printjoin and Punctuation Handling for Indexing and Querying
1.7 Case-sensitive Thesaurus Expansion in Queries
1.8 Proper Names File (ctxprop.dmp) No Longer Provided
1.9 ctxsrvx Executable Obsolete
NEW FEATURES
2.1 Text Management (Loading, Storage, Filtering, etc.)
2.1.1 Case-sensitive Thesauri
2.1.2 Support for Startjoin and Endjoin Characters
2.1.3 Support for FTP in URL Data Store
2.1.4 Support for Document Update/Export in ctxload
2.1.5 Section and Section Group Definition
2.1.6 New Format for Master-Detail Tables
2.2 Indexing
2.2.1 Control Over Index Table Poplation During Indexing
2.2.2 Control Over DML Trigger Creation During Indexing
2.2.3 Case-sensitive Text Indexing
2.3 International
2.3.1 NLS Lexing
2.3.2 Enhanced Fuzzy Match for Non-English Languages and OCR Text
2.3.3 Chinese and Korean Lexers (Production Status)
2.3.4 Predefined Stoplists for Western European Languages
2.3.5 German Composite Text Indexing
2.4 Querying
2.4.1 Structured Data in In-memory Queries
2.4.2 Named Section Searching
2.4.3 Post-query Counting of Query Hits
2.4.4 Query Feedback Table
2.4.5 Case-sensitive Text Queries
2.4.6 NEAR Operator with Multiple Terms
2.5 Viewing
2.6 Linguistic
2.6.1 Sentence-level Gists and Theme Summaries
2.6.2 Improved Flexibility for Gist and Theme Summary Generation
2.6.3 Theme Highlighting
2.6.4 Improved Performance for Linguistics
2.6.5 Hierarchy Information for Theme Generation
2.7 ConText Workbench
2.7.1 Web-based Administration Tool
2.7.2 TextServer3 Migration Utility
2.7.3 Netscape Plug-in Viewer
NEW CONTEXT DATA DICTIONARY OBJECTS
3.1 New Tiles
3.2 New Predefined Preferences
3.3 New Template Policies
3.4 New Procedures and Functions
3.5 New Views
DOCUMENTATION CHANGES
4.1 Workbench User's Guide (NEW)
4.2 Administrator's Guide
4.3 Application Developer's Guide
INSTALLATION ISSUES
5.0 Location of ConText Installation Information
5.1 Perform Oracle8 and ConText Installation Separately
UPGRADE ISSUES
6.0 Requirements for Upgrading
6.1 Installer Upgrade Options for ConText 2.3.6
6.2 Manual Upgrade
6.3 Upgrading ConText Indexes
USAGE ISSUES
7.1 New Features Which Require Reindexing
7.2 Enabling One-Step Queries
7.2.1 Setting TEXT_ENABLE for All Users
7.2.2 Setting TEXT_ENABLE for the Session
7.3 Supplied External Filters
7.3.1 Installing the Filters
7.3.2 Using the Filters
7.4 Enabling the Linguistics
LINGUISTIC ISSUES
8.1 CTX_PROPER_NAMES Seed File No Longer Provided
8.2 Importing Knowledge Catalog/Lexicon Data
8.3 Starting ConText Servers for Theme Indexing and Querying
8.4 Specifying Settings for Linguistic Processing
8.5 Changing Settings for Theme Indexing and Queries
8.6 Obsolete Linguistic Setting Configurations
FIXES/ENHANCEMENTS
9.1 Fixes/Enhancements in Release 2.3
KNOWN LIMITATIONS
10.1 One-Step Queries in PL/SQL Not Supported (344159)
10.2 Indexing with Soundex Fails When Many Results Tables are
Present (401217)
10.3 One-Step Queries for LONG Columns in Remote Tables Not
Supported (436969)
10.4 Resume Index Creation/Optimization Not Supported (483325)
10.5 Scoring for NEAR Operator Inconsistent with
Other Operators
-----------------------------------------------------------------------------
**********************
* *
* Introduction *
* *
**********************
0.1 Purpose of this README
--------------------------
This README file contains information about ConText, Release 2.3. It documents
any differences between ConText, Release 2.3, and its documented
functionality, as well as fixed bugs, and known problems
and workarounds.
0.2 Cover Letter and Licensing
------------------------------
Please read the cover letter included with your Oracle8 package.
It contains important information about licenses
for Oracle8 cartridges.
0.3 Oracle8 ConText Cartridge Documentation Available in this Release
-----------------------------------------------------------------
Oracle8 ConText Cartridge QuickStart
Oracle8 ConText Cartridge Administrator's Guide
Oracle8 ConText Cartridge Application Developer's
Guide
Oracle8 Error Messages
Oracle8 ConText Cartridge Workbench User's Guide
-----------------------------------------------------------------------------
*********************************
* *
* Changes to ConText Option *
* *
*********************************
-------------------
NOTE: The following changes have been made from the previous release of
ConText. These changes may affect the functionality and operation of
the current release.
-------------------
1.1 New Scoring Method for Text Queries
=======================================
In previous releases, scoring was based on the number of occurrences of the
query term in the document. Each occurrence was assigned a default value
of 10, with the maximum score for a document set
to 100.
In Release 2.3, a new scoring method is introduced. This method continues to
use number of occurrences, but includes document statistics, including the
number of documents in the text column and the total number of documents
returned in the query results, when calculating the
overall score.
All of the operators, except for the NEAR (;) operator, which measures
distance between terms, function exactly as before.
In addition, the maximum score for a document is still 100; however, this
threshhold is not easily reached because the number of documents in which
a term occurs directly affects the number of occurrences required to
reach a score of 100.
-------------------
NOTE: DML affects the score results. In other words, a query for a specific
token on two different occasions may not return the same score for a
given document if DML has taken place between these
2 occasions.
In addition, the new scoring method does not affect scoring for
theme queries.
-------------------
1.2 Processing of Stopwords in Text Queries Enhanced
====================================================
In previous releases, if a stopword was specified as one of the operands
in a query expression, ConText returned an error and did not process the
query.
In Release 2.3, ConText replaces the stopword(s) with a NULL value and
processes the query to return results. No error is
returned.
-------------------
NOTE: The effects of the replacement on the query varies depending on the
operators in the query expression.
-------------------
In most cases, the results returned by the query reflect the remaining operands
and operators in the expression. In a few select cases, such as query
expressions with a stopword as the first operand for the NOT (~) operator, no
results are returned.
The query feedback table, a new feature in Release 2.3, can be used to view
the replacement that ConText generates for queries that contain one or more
stopwords as operands.
1.3 Changes to ctxload Parameters
=================================
In Release 2.3, ctxload has been enhanced to provide the following
functionality:
-- document update and export, which enables users to update the
contents of the text column for a specified row or to
write the text column contents for the row to an
operating-system file.
-- import/creation of case-sensitive thesauri
To support these enhancements, the following command-line arguments have
been changed or added:
Release 2.0 argument and purpose Release 2.3 argument and purpose
-------------------------------- -------------------------------------
-file specified the name of a text -file same as before; however, it is
or thesaurus file to load, now also used to specify the
or a thesaurus export file name of the file from which
to create. text is loaded during document
update or the name of the file
created
during document export.
-name specified the name of the -name same as before; however, it is
table to which text is loaded, now also used to specify the
the name of the thesaurus to policy name for the text
be created, or the name of the column to be updated or.
thesaurus to be exported. exported.
-export specifies that ctxload exports
the contents of the text
column for a row into an
operating-system file.
-update specifies that ctxload updates
the text column for a row with
the contents of a specified
operating-system file.
-pk specifies the primary key for
the row for which the text
column is updated/exported.
-thescase specifies whether the
thesaurus created by
ctxload is case-sensitive.
1.4 New Arguments for PL/SQL Stored Procedures and Functions
============================================================
The following new arguments have been added to the stored procedures and
functions in the ConText PL/SQL packages:
Package Procedure/Function New Argument Purpose
----------- ------------------- --------------- ---------------------------
CTX_DDL CREATE_INDEX create_trig Specify whether the DML
trigger is created during
indexing
pop_index Specify whether the ConText
index tables are populated
during indexing.
CTX_THES CREATE_THESAURUS case_sensitive Specify whether the thesurus
is case-sensitive.
CTX_QUERY OPEN_CON struct_query Include structured data in
an in-memory query.
CTX_LING REQUEST_GIST glevel Specify the type (paragraph or
sentenct) of Gist/theme
summary to create.
pov Specify whether to create a
Gist for a document or a theme
summary for one of the document
themes. If no value is
specified, a Gist and theme
summaries for all of the
document themes are created.
Each new argument has a default value. As a result, most of your applications
which call these procedures/functions will not require modification, provided
you want to used the defaults in the application.
-------------------
NOTE: Oracle Forms applications that call these procedures/functions will
require either valid or NULL values to be specified for each of the
new arguments.
-------------------
1.5 Supplied External Filters Installed/Upgraded with ConText
=============================================================
In previous releases, the external filters provided by Oracle were
distributed on a separate CD-ROM. These filters had to be manually
installed after installation of ConText. In addition, wrappers had to be
created for each external filter that you wanted
to use.
In Release 2.3, the executables, as well as the wrappers, for the external
filters are installed automatically. If you upgrade from a previous
release, the old filters are upgraded to the new
filters.
1.6 Enhanced Printjoin and Punctuation Handling for Indexing and Querying
=========================================================================
In previous releases, non-alphanumeric characters that appeared at the end of
a token and were defined as printjoins (attribute for the BASIC LEXER Tile)
were removed during indexing and queries. If the same printjoin character
appeared consecutively, all but one of the printjoins
were removed.
In addition, the 'punctuations' attribute for the BASIC LEXER Tile
was not implemented. All non-alphanumeric characters that appeared at the end
of a token were simply removed during indexing and
queries.
In Release 2.3, all printjoin characters, including consecutive printjoins, are
treated as alphanumeric characters and included in the index entry for the
token to which they are attached; however, if the printjoin character is also
defined as a punctuation character, the printjoin character is only treated as
an alphanumeric character if the character immediately following it is a
printjoin, skipjoin, or alphanumeric character.
For example, if the period (.) is defined as both a printjoin and a
punctuation character, the following transformations take place during
indexing and querying:
.doc --> .doc
dog.doc --> dog.doc
dog..doc --> dog..doc
dog. --> dog
dog... --> dog..
-------------------
NOTE: Because of the way the basic lexer identifies and stores tokens during
indexing, the change to printjoin handling has an effect on both
querying and highlighting of documents that have
already been indexed.
You may want to drop and recreate your existing index(es) if you
defined printjoin characters for the BASIC LEXER Tile in your Lexer
preferences and any of the following conditions
apply:
-- consecutive printjoins occur in the tokens in your documents
-- printjoins occur at the end of the tokens in your documents
-- same characters defined as **both** printjoins and
punctuations for the BASIC LEXER Tile
-------------------
1.7 Case-sensitive Thesaurus Expansion in Queries
=================================================
If a case-sensitive thesaurus is used in a query expansion, the thesaurus
lookup is performed using the query terms exactly
as entered in the query.
For example, two queries for 'Turkey' and 'turkey', using a case-sensitive
thesaurus, may return two different expansions, whereas the same queries
using a case-insensitive thesaurus would return the
same expansions.
-------------------
NOTE: To see the expansions performed using thesauri, use the query
feedback table, a new feature in Release 2.3, which provides detailed
information about the expansions that ConText performs in a query.
-------------------
1.8 Proper Names File (ctxprop.dmp) No Longer Provided
======================================================
The ctxprop.dmp file, which is used to populate the CTX_PROPER_NAMES table,
is no longer included in the ConText distribution.
The ConText Linguistics case-sensitivity routines no longer use the
CTX_PROPER_NAMES table to process all-uppercase and
all-lowercase documents.
1.9 ctxsrvx Executable Obsolete
===============================
In previous releases, the Knowledge Catalog/Lexicon used by ConText to
generate theme indexes and linguistic output was compiled with the ctxsrv
executable. For users that did not require the linguistic capabilities of
ConText, a second executable, ctxsrvx, was provided. This executable was
compiled without the Knowledge Catalog/Lexicon and could be used to start
ConText servers with linguistics disabled.
With Release 2.3, the Knowledge Catalog/Lexicon is stored in a database table
owned by CTXSYS. Linguistic information is retrieved by ConText from the
table as needed.
As a result, the ctxsrvx executable is no longer needed. For backward
compatibility, ctxsrvx may still be provided; however, it is either a
link/shortcut to the ctxsrv executable or identical
to ctxsrv.
-------------------
NOTE: As a result of the Knowledge Catalog/Lexicon now being stored in a
database table, to use the Linguistics, you must import the data
from the provided file into the database table after installation
or upgrade.
For more information, see "7.4 Enabling the Linguistics" in this
document.
-------------------
-----------------------------------------------------------------------------
********************
* *
* New Features *
* *
********************
ConText, Release 2.3, has a number of new features, designed to provide
more flexibility for data storage, indexing, and queries, as well as improve
query performance. The new features are grouped
according to function:
2.1 Text Management (loading, storage, filtering, etc.)
2.2 Indexing
2.3 International
2.4 Querying
2.5 Viewing
2.6 Linguistics
2.7 ConText Workbench
For more information about the new text management, indexing, and
international features, see "Oracle8 ConText
Cartridge Administrator's Guide".
For more information about the new querying, viewing, and Linguistic features,
see "Oracle8 ConText Cartridge Application Developer's
Guide".
For more information about the new ConText Workbench features, see "Oracle8
ConText Cartridge Workbench User's Guide".
2.1 Text Management (Loading, Storage, Filtering, etc.) Features
================================================================
2.1.1 Case-sensitive Thesauri
-----------------------------
ConText supports creating case-sensitive thesauri through either
CTX_THES.CREATE_THESAURUS or the thesaurus load functionality
in ctxload.
In a case-sensitive thesaurus, terms are stored exactly as entered. In a
case-insensitive thesaurus, terms are stored in all-uppercase, regardless of
the case in which they were entered.
-------------------
NOTE: Case-sensitive thesauri have an effect on query expansion. For
more information, see "1.7 Case-sensitive Thesaurus Expansion in
Queries".
-------------------
2.1.2 Support for Startjoin and Endjoin Characters
--------------------------------------------------
Through the new 'startjoin' and 'endjoin' attributes provided in the BASIC
LEXER Tile, users can specify characters that, when they appear at the
beginning and end of a token, explicitly start/end the token. In addition,
those characters specified as startjoins and endjoins are included in the
ConText index entry for the token.
Startjoins and endjoins are especially useful for defining document sections
to enable named section searching.
For more information about document sections and section searching, see
"2.1.5 Section and Section Group Definition" and "2.4.2 Named Section
"Searching
2.1.3 Support for FTP in URL Data Store
---------------------------------------
The URL data store (URL Tile) now supports the File Transfer Protocol (FTP)
in addition to HTTP and local file protocol.
URLs that use FTP, either on the Internet or on private intranets, can now be
accessed for indexing and viewing.
2.1.4 Support for Document Update/Export in ctxload
---------------------------------------------------
In previous releases, ctxload could only be used to create new rows and
insert new data into the text column for a given row. It could not be used
to update an existing row.
In Release 2.3, ctxload supports updating the text column for a row. In
addition, ctxload can be used to export the text column for a row to an
operating-system file.
2.1.5 Section and Section Group Definition
------------------------------------------
In Release 2.3, ConText supports restricting text queries to a user-defined
section. Sections are identified by user-defined start and end tags and are
grouped into section groups. A section group is attached to a text column
through the text indexing policy for the column and section information is
stored in the ConText index tables during indexing.
To enable named section searching, ConText provides new PL/SQL procedures
for creating and managing sections and section groups:
-- ADD_SECTION
-- CREATE_SECTION_GROUP
-- DROP_SECTION_GROUP
-- REMOVE_SECION
ConText also provides two new attributes for managing sections and section
groups:
-- 'section_group' (GENERIC WORD LIST Tile), which specifies the name of the
section group to be assigned to a text column
-- 'keep_tag' (HTML FILTER Tile), which specifies HTML tags to be retained by
the HTML filter for use in defining and identifying sections for HTML
documents.
Finally, Oracle provides a new template policy and new predefined preferences
for quickly and easily enabling basic section searching
of HTML documents:
-- New template policy: TEMPLATE_BASIC_WEB
-- New predefined preferences:
-- BASIC_HTML_FILTER
-- BASIC_HTML_LEXER
-- BASIC_HTML_WORDLIST
For more information about section searching, see
"2.4.2 Section Searching".
2.1.6 New Format for Master-Detail Tables
-----------------------------------------
In previous releases, ConText required you to create a policy on the detail
table in a master-detail relationship. This resulted in potentially slower
queries for text/themes and structured data, as well as slower DML and
non-intuitive one-step queries.
ConText, Release 2.3, supports defining a policy on the master table, rather
than the detail table. The detail table name and attributes are specified in
the Data Store preference, rather than in the policy.
To implement the new master/detail data store, a new Data Store Tile, MASTER
DETAIL NEW, is provided.
2.2 Indexing Features
======================
2.2.1 Control Over Index Table Poplation During Indexing
--------------------------------------------------------
ConText provides a new parameter, pop_index, for CTX_DDL.CREATE_INDEX. This
new parameter allows a user to create the ConText index tables for a policy
without generating the index. The ConText index tables can be populated
later through automatic DML, if enabled, or through manual DML
(CTX_DML.REINDEX).
2.2.2 Control Over DML Trigger Creation During Indexing
-------------------------------------------------------
ConText provides a new parameter, create_trig, for CTX_DDL.CREATE_INDEX. This
new parameter allows a user to create a ConText index, but supress creation
of the DML trigger that enables automatic DML for
the index.
Updating of the index can then be controlled through manual DML
(CTX_DML.REINDEX).
2.2.3 Case-sensitive Text Indexing
----------------------------------
In previous releases, ConText automatically converted all tokens to
all-uppercase when creating text index entries. As a result, text queries
were always case-insensitive.
In Release 2.3, to support case-sensitive text queries, ConText provides a
new parameter, case_sensitive, for CTX_DDL.CREATE_INDEX. This new parameter
allows a user to create a ConText index in which the index entries are
recorded exactly as the tokens appear in the text.
2.3 International Features
==========================
2.3.1 NLS indexing
------------------
ConText supports the indexing of documents stored in any NLS
character set. Among other benefits, this feature enables the
indexing of documents based on the Unicode standard.
2.3.2 Enhanced Fuzzy Match for Non-English Languages and OCR Text
-----------------------------------------------------------------
Fuzzy matching is now available in German, French, Italian, Spanish,
and Dutch, as well as English.
In addition, ConText supports enhanced fuzzy matching for text that has been
scanned using Optical Character Recognition (OCR).
To enable fuzzy matching for these languages and OCR text, ConText provides
new values for the 'fuzzy_match' attribute (GENERIC
WORD LIST).
2.3.3 Chinese and Korean Lexers (Production Status)
--------------------------------------------------
The Chinese and Korean lexers, which enable full text indexing in these
languages, have a status of full production in this
release.
2.3.4 Predefined Stoplists for Western European Languages
----------------------------------------------------------
Stoplists, in the form of predefined Stoplist preferences, are provided for
the following Western European languages:
-- French
-- German
-- Italian
-- Spanish
2.3.5 German Composite Text Indexing
------------------------------------
To support querying for root nouns in German-language text and retrieving
text that contains either the root nouns or any compound nouns in which the
roots appear, the text lexer used for indexing German-language text (BASIC
LEXER) now provides an attribute named 'composite' to enable decompounding of
compound nouns. If enabled, this feature separates compound nouns into their
root nouns and stores the roots, as well as the original compound nouns, in
the text index.
-------------------
NOTE: German composite indexing does not support case-sensitive indexing,
another new feature in 2.3.6. Tokens in a German composite index
are always stored in all-uppercase.
-------------------
2.4 Querying Features
=====================
2.4.1 Structured Data in In-memory Queries
------------------------------------------
In addition to text search criteria, application developers can include
structured data search criteria in in-memory queries.
The CTX_QUERY.OPEN_CON procedure provides a new parameter, struct_query, to
enable structured data criteria in in-memory queries.
2.4.2 Named Section Searching
-----------------------------
ConText now supports restricting a text query to a specified, user-defined
section.
One or more sections are created by the text administrator and assigned to a
section group, which is then assigned to a policy for a text column. During
creation of the ConText index, the section information for each token is
stored in the index along with the token.
Using the new WITHIN operator, text queries against the column can be
restricted to one of the sections for the column.
For more information about defining sections and section groups, see
"2.1.5 Section and Section Group Definition".
2.4.3 Post-query Counting of Query Hits
---------------------------------------
In previous releases, the only method of counting the number of hits in a
two-step or in-memory query was to first call CTX_QUERY.COUNT_HITS to return
the number of hits, then submit the query to return
the results.
In Release 2.3, a new function, CTX_QUERY.COUNT_LAST, has been added, which
returns a count of the number of rows from the last two-step or in-memory
query.
2.4.4 Query Feedback Table
--------------------------
In Release 2.3, ConText provides a new procedure, CTX_QUERY.FEEDBACK, which
generates information about the expansions, if any, that occur in a query, as
well as the precedence of the operators and operands in the query, and stores
the information in a database table. This query feedback table can then be
queried using standard SQL to return the information
generated about the query.
In general, CTX_QUERY.FEEDBACK is run prior to submitting a ConText query
so that the information can be used to refine the query before the query is
submitted.
For example, the query feedback can be used to inform the user entering the
query that their current query will be expanded to include a large number of
terms and whether the user wants the query to be
submitted as entered.
2.4.5 Case-sensitive Text Queries
---------------------------------
In Release 2.3, if a case-sensitive text index is created for a column, text
queries on the index are case-sensitive, resulting
in higher precision.
For example, in previous releases, a text query for "Oracle" returned
all documents that contained any occurrences of the term "oracle", "Oracle",
"ORACLE", etc.
In this release, a text query for "Oracle" on a case-sensitive index returns
only the documents that contain the term "Oracle".
2.4.6 NEAR Operator with Multiple Terms
---------------------------------------
In Release 2.3, the NEAR operator can be used to score retrieved documents
based on the proximity of two or more terms.
2.5 Viewing Features
====================
See "2.6.3 Theme Highlighting" and "2.7.3 Netscape Plug-in Viewer" for more
information about the new document viewing features
in Release 2.3.
2.6 Linguistic Features (English-text Only)
===========================================
-------------------
NOTE: Beginning with this release, "generic Gists" are referred to as
"Gists" and "point-of-view (POV) Gists" are referred to as
"theme summaries".
-------------------
2.6.1 Sentence-level Gists and Theme Summaries
----------------------------------------------
In Release 2.3, application developers can choose to generate either
paragraph-level (DEFAULT) or sentence-level Gists/theme
summaries.
Paragraph summarization selects the most representative paragraphs in a
document to build Gists and theme summaries. Sentence-level summarization
selects the most representative sentences.
The CTX_LING.REQUEST_GIST procedure provides a new parameter, glevel, to
enable paragraph-level and sentence-level Gists.
2.6.2 Improved Flexibility for Gist and Theme Summary Generation
----------------------------------------------------------------
In Release 2.3, application developers have the following options when
requesting Gists and theme summaries:
1) document Gist and theme summaries for each document theme (DEFAULT)
2) document Gist only
3) theme summary for specified theme only
The CTX_LING.REQUEST_GIST procedure provides a new parameter, pov, which can
be used to limit Gist/theme summary generation to the document Gist only or
to a theme summary for a specific theme in the document.
2.6.3 Theme Highlighting
------------------------
In Release 2.3, the CTX_QUERY.HIGHLIGHT procedure now supports generating
highlight information for a specified theme in a specified document. With
theme highlighting, the paragraphs that contribute to the theme for a
document are identified and markup information or the actual marked-up text
is stored in output tables specified by the user.
2.6.4 Improved Performance for Linguistics
------------------------------------------
In Release 2.3, the performance of the Linguistics has been greatly improved.
In addition, the ctxsrv executable has been reduced in size by approximately
80%, resulting in less memory required for Linguisitic
processing.
2.6.5 Hierarchy Information for Theme Generation
------------------------------------------------
In previous releases, CTX_LING.REQUEST_THEMES returned only the themes
for a document and stored each theme as a row in
a user-specified table.
In Release 2.3, if a document theme has an entry in the ConText Knowledge
Catalog, REQUEST_THEMES returns the parent concept for the theme, as well as
all the other higher-level concepts for the theme, as stored in the Knowledge
Catalog. In effect, REQUEST_THEMES returns the full Knowledge Catalog
hierarchy of concepts for each document theme.
A theme and its hierarchy is stored as a single string, separated by
commas (:). The top level concept in the hierarchy occurs first in the
string, followed by each successively lower-level concept, with the actual
theme occurring last.
In addition, ConText provides two new procedures, CTX_LING.SET_FULL_THEMES
and CTX_LING.GET_FULL_THEMES, for managing the theme hierarchies returned by
REQUEST_THEMES.
2.7 ConText Workbench Features
==============================
2.7.1 Web-based Administration Tool
-----------------------------------
In previous releases, the GUI System Administration tool was only available
for the Windows NT and Windows 95 platforms
An HTML version of the System Administration tool is now provided for managing
ConText from any Web-enabled environment.
2.7.2 TextServer3 Migration Utility
-----------------------------------
A new utility is provided for migrating a TextServer3 data dictionary to a
ConText data dictionary.
2.7.3 Netscape Plug-in Viewer
-----------------------------
In Release 2.3, the ConText Workbench provides a plug-in for viewing documents
with query terms highlighted within a Netscape browser.
For Microsoft Word (v6.0 and earlier) and WordPerfect (v6.0 and earlier)
documents, the Netscape plug-in provides WYSIWYG
viewing of the documents.
For those document formats for which ConText supports filtering, but not
WYSIWYG viewing, the viewer converts the documents
to ASCII before displaying.
-----------------------------------------------------------------------------
*******************************************
* *
* New ConText Data Dictionary Objects *
* *
*******************************************
-------------------
NOTE: For a list of the new arguments provided for exisiting procedures and
functions, see "1.4 New Arguments for PL/SQL Stored Procedures and
Functions".
-------------------
3.1 New Tiles
=============
ConText, Release 2.3, provides a new Data Store Tile, MASTER DETAIL NEW, to
support the new method for defining master-detail relationships between
tables.
3.2 New Predefined Preferences
==============================
ConText, Release 2.3, provides the following new preferences for quickly and
easily enabling basic section searching in HTML documents:
-- BASIC_HTML_FILTER
-- BASIC_HTML_LEXER
-- BASIC_HTML_WORDLIST
3.3 New Template Policies
=========================
ConText, Release 2.3, provides a new template policy, TEMPLATE_BASIC_WEB, that
can be used to create section-enabled policies for columns that contain URLs to
HTML documents.
It uses the URL Data Store preference and the new predefined preferences (see
above).
3.4 New Procedures and Functions
================================
ConText, Release 2.3, provides new PL/SQL procedures and functions to enable
the following new features:
-- Named Section Searching:
-- CTX_DDL.ADD_SECTION
-- CTX_DDL.CREATE_SECTION_GROUP
-- CTX_DDL.DROP_SECTION_GROUP
-- CTX_DDL.REMOVE_SECION
-- Query Feedback: CTX_QUERY.FEEDBACK
-- Query Hits Counting: CTX_QUERY.COUNT_LAST
-- Hierarchy Information for Theme Generation:
-- CTX_LING.SET_FULL_THEMES
-- CTX_LING.GET_FULL_THEMES
3.5 New Views
=============
ConText, Release 2.3, provides the following new views for monitoring
sections and section groups:
-- CTX_ALL_SECTION GROUPS
-- CTX_ALL_SECTIONS
-- CTX_USER_SECTION_GROUPS
-- CTX_USER_SECTIONS
CTX_ALL_SECTION_GROUPS displays the ID, name, and owner of all the
section groups that have been created.
CTX_ALL_SECTIONS displays the ID, name, owner, and section definition
(start tags, end tags, etc.), for each section that has been created.
It also displays the ID for the section group to
which the section belongs.
CTX_USER_SECTION_GROUPS displays the name of all the section groups that
have been created for the current user.
CTX_USER_SECTIONS displays the ID, name, and section definition (start
tags, end tags, etc.), for each section that has been created for the
current user. It also displays the ID for the section group to which the
section belongs.
-----------------------------------------------------------------------------
*****************************
* *
* Documentation Changes *
* *
*****************************
4.1 Workbench User's Guide (**NEW**)
====================================
In Release 2.3, a new manual is included in the ConText documentation set.
The ConText Workbench user's Guide serves as a single, complete source of
setup and usage information for all the components that comprise the Oracle
ConText Option Workbench.
It combines the descriptions and usage information for existing Workbench
components (collected from various other ConText documentation) with the
descriptions, setup information, and usage information for the new components
in the ConText Workbench, Release 2.3:
-- Administration tools
-- System Administration for Windows NT and 95
-- Configuration Manager for Web environments (**NEW**)
-- Sample Oracle Forms application
-- Document viewer
-- custom control
-- Netscape plug-in (**NEW**)
-- Input/Output Utility
4.2 Administrator's Guide
=========================
-- ConText, Release 2.3, new features documented
-- Chapters removed:
-- "Chapter 7, Configuring ConText Option"
-- "Chapter 8, Tuning ConText Option"
-------------------
NOTE: These chapters will be available in a new manual, "Oracle
ConText Option Tuning", which will be released after
Release 2.3.
-------------------
-- Reference section ("Part IV") removed and chapters reorganized into
relevent section:
-- "Chapter 9, Executables and Utilities" split into two chapters:
-- "ConText Server Executables and Utilities" in "Part I"
-- "Text Loading Utility" in "Part
II"
-- "Chapter 10, Data Dictionary" merged into "Understanding the ConText
Data Dictionary" chapter
-- "Chapter 11, PL/SQL Packages" split into two chapters:
-- "PL/SQL Packages - Administration" in "Part I"
-- "PL/SQL Packages - Text Management"
in "Part II"
-- "Appendix A, ConText Server and Queue Views" and "Appendix B, ConText Data
Dictionary Views" combined into a single
appendix named "ConText Views"
-- New appendix named "Supplied Stoplists", which contains a list of the stop
words for each of the predefined Stoplist preferences.
4.3 Application Developer's Guide
=================================
-- ConText, Release 2.3, new features documented
-- New Chapters:
-- "Chapter 5: Query Expression Feedback"
-- "Appendix C: Stopword Transformations"
-- Chapters removed:
-- "Chapter 1: Introduction" removed from
manual
-- "Appendix C: Forms Sample Application" moved to new manual, "Oracle
ConText Option Workbench User's Guide"
-- "Appendix D: Input/Output Utility" moved to new manual, "Oracle8
ConText Cartridge Workbench User's Guide"
-- Chapters enhanced:
-- "Chapter 3, Query Methods" (renumbered to "Chapter 2") expanded
to include sections on counting query hits.
-- "Chapter 5, Theme Queries" (renumbered to "Chapter 4") expanded
and reorganized into three sections:
-- "Understanding Theme Queries"
-- "Constructing Theme Queries"
-- "Refining Theme Queries"
-- "Chapter 6, Viewing Highlighted Text" renamed to "Chapter 6:
Document Presentation" to reflect the addition of new document
presentation features for Release 2.3
-----------------------------------------------------------------------------
***************************
* *
* Installation Issues *
* *
***************************
5.0 Location of ConText Installation Information
================================================
The information required for installing ConText is located in the Oracle8
installation documentation for your operating system.
Additional installation information for ConText may be located in the
Oracle8 Server release notes for your operating system.
5.1 Perform Oracle8 and ConText Installation Separately
=======================================================
Because the ConText data dictionary should be installed into an existing
tablespace, Oracle Corporation suggests installing ConText in a separate step
after Oracle8 has been installed and the appropriate tablespaces have been
created.
After Oracle8 is installed and the appropriate tablespaces are created, return
to the Installer screen which lists the available produts for installation and
select the ConText entry.
-----------------------------------------------------------------------------
**********************
* *
* Upgrade Issues *
* *
**********************
6.0 Requirements for Upgrading
==============================
Upgrading from a previous version of ConText must
occur in two separate steps:
1) Upgrade/migrate your Oracle database to the version 8.0.4
2) Upgrade ConText from the previous version to version
2.3.6
-------------------
NOTE: Version 8.0.4 of Oracle is the only supported Oracle database version
for version 2.3.6 of ConText.
-------------------
In addition, all ConText servers that are currently running must be shut down
BEFORE upgrade.
For more information about upgrading ConText, see the Oracle8 Server
installation documentation for your operating system.
6.1 Installer Upgrade Options for ConText 2.3.6
===============================================
When upgrading to ConText, Release 2.3, the Oracle Installer provides the
following choices.
Migration:
-- 1.1.2 (7.3.2) to 2.3.6 (8.0.4)
-- 2.0.4 (7.3.3) to 2.3.6 (8.0.4)
-- 2.3.4 (7.3.4) to 2.3.6 (8.0.4)
Upgrade:
-- 2.0.6 (8.0.3) to 2.3.6 (8.0.4)
6.2 Manual Upgrade
==================
If you are upgrading manually, you must copy the new software (executables,
scripts, packages, etc.) to the appropriate subdirectories in the ConText
directory, then run the appropriate scripts for your
version of ConText:
1.1.2 to 2.0.4 --> sys20000.sql as SYS
upg20000.sql as CTXSYS
2.0.4 to 2.3.4 --> upg23400.sql as CTXSYS
2.3.4 to 2.3.6 --> **NONE** (no database changes)
-------------------
NOTE: After manual upgrade from 1.1.2, if you want to use the ConText
Linguistics, you must import the ctxset.dmp file, using the Import/
Export utility provided by Oracle:
IMP ctxsys/<passwd> file=ctxset.dmp full=y
ignore=y
The ctxset.dmp file is generally located in the admin subdirectory in
the ConText directory in your Oracle home directory; however, the
exact location is operating system dependent.
For more information about the exact location of the file, see the
Oracle8 Server documentation specific to your operating system.
-------------------
6.2 Upgrading ConText Indexes
=============================
After upgrading to Release 2.3 from a previous release, you **MUST** call the
CTX_DDL.UPGRADE_INDEX procedure once for each existing ConText index.
UPGRADE_INDEX converts ConText indexes to the current
release.
UPGRADE_INDEX can be called by the owner of the policy for the index or by
CTXSYS.
In the following example, the ConText index for the 'html_docs' policy is
upgraded to version 2.3 by the policy owner:
exec ctx_ddl.upgrade_index('html_docs')
For more information about CTX_DDL.UPGRADE_INDEX, see "Oracle8 ConText
Cartridge Administrator's Guide".
-----------------------------------------------------------------------------
********************
* *
* Usage Issues *
* *
********************
7.1 New Features Which Require Reindexing
=========================================
To use the following new features or enhancements, you must drop existing
ConText indexes on the text columns for which you want to use the new feature,
then create new ConText indexes for the columns:
-- named section searching
-- startjoin and endjoin characters
-- new master/detail data store method
-- enhancements for printjoin and punctuation characters
-- case-sensitive text indexing
-- German composite text indexing
-------------------
NOTE: In addition to creating new ConText indexes, you also may have to
perform some setup to use these features.
For example, to use section searching for a text column, you must
create a section group, create sections for the section group, and
assign the section group to the policy for the text column. Then you
can create the ConText index for the column.
-------------------
7.2 Enabling One-Step Queries
=============================
If you want to use one-step queries in ConText, you must set the ConText
initialization parameter TEXT_ENABLE to TRUE. TEXT_ENABLE enables Oracle8
to recognize the CONTAINS SQL function utilized in
one-step queries.
You can set TEXT_ENABLE for all users and sessions in the initsid.ora file.
You can also set TEXT_ENABLE for the current session using the SQL command,
ALTER SESSION.
-------------------
NOTE: Once you have set TEXT_ENABLE, start one or more ConText servers
with the Query (Q) personality to ensure one-step queries are
processed.
-------------------
7.2.1 Setting TEXT_ENABLE for All Users
---------------------------------------
To set TEXT_ENABLE for all users, perform the following
steps:
1. Shut down the database.
2. Add the following line to the initsid.ora file:
text_enable=true
-------------------
NOTE: Setting TEXT_ENABLE for all users does not create a security
violation. It only ensures that one-step text queries can be
processed.
-------------------
7.2.2 Setting TEXT_ENABLE for the Session
-----------------------------------------
To set TEXT_ENABLE for the current session only, issue the following SQL
command:
alter session set text_enable = true
7.3 Supplied External Filters
=============================
ConText, Release 2.3, supports using external filters to filter text for
creating ConText indexes and highlighting. External filters are provided by
ConText for a number of formats, including:
-- AmiPro
-- Lotus 1-2-3
-- Microsoft Excel
-- Microsoft PowerPoint
-- Microsoft Word
7.3.1 Installing the Filters
----------------------------
The external filters are supplied as executables which are automatically
installed with ConText. In addition, wrappers for each of the executables are
installed with ConText. The location of the filter executables and wrappers
is dependent on your operating system.
For more information about the location of the filter executables and
wrappers, see the Oracle8 installation documentation specific to your
operating system.
-------------------
NOTE: In previous releases, the supplied external filters were included on
a separate CD-ROM and had to be installed manually.
In this release, the installation of the supplied external filters is
handled by the Oracle Installer.
-------------------
7.3.2 Using the Filters
-----------------------
To use one or more external filters for a text column, create a Filter
preference that calls the wrapper for each desired filter, then use the
preference in the policy for the column.
-------------------
NOTE: The type of column (single-format or mixed-format) determines the Tile
and attributes that you must set when creating the
Filter preference.
If the column stores documents in a single format, use the USER FILTER
Tile and the 'command' attribute.
If the column stores documents in more than one format, use the
BLASTER FILTER Tile and the 'executable' attribute.
-------------------
For more information about creating Filter preferences for external filters,
see "Oracle8 ConText Cartridge Administrator's
Guide".
7.3.3 PDF Filter Limitations
----------------------------
The PDF filter provided for all platforms other than Windows NT and Sun Solaris
2.x has a status of BETA. The BETA PDF filter does not support multi-column
documents or documents over 1 Mb in size.
For Windows NT and Sun Solaris 2.x, the PDF filter has a status of production.
The filter correctly processes multi-column and large PDF documents; however,
the filter replaces bullet marks with characters.
7.4 Enabling the Linguistics
============================
In Release 2.3, the Knowledge Catalog/Lexicon utilized by the ConText
Linguistics is stored in a database table owned by CTXSYS, rather than
compiled as part of the ctxsrv executable.
However, the table is not populated during installation/upgrade of ConText.
If you want to create theme indexes, perform theme queries, or generate
linguistic output for your English text, the data for the Knowledge Catalog
table must be imported after installation/upgrade from the ctxlex.dmp export
file provided by ConText.
The following procedure provides instructions for
importing the data:
1) Ensure the tablespace for CTXSYS has at least
30-40 Megabytes available.
2) Create a rollback segment in a tablespace that has at least 30 Megabytes
available. For example:
sql> create rollback segment rollbk_temp tablespace drsys storage (
2 initial 5M next 5M optimal 10M minextents
2 maxextents unlimited);
This example creates a rollback segment named 'rollbk_temp' in a tablespace
named 'drsys'.
3) Bring the new rollback segment online and bring all existing rollback
segments, **EXCEPT** system offline.
4) Use the IMP utility to import the ctxlex.dmp file
as CTXSYS:
IMP ctxsys/<passwd> file=ctxlex.dmp full=y
ignore=y buffer=50000 feedback=50000
5) Bring the new rollback segment offline and bring all existing rollback
segments online.
-------------------
NOTE: The ctxlex.dmp file is generally located in the admin subdirectory in
the ConText directory in your Oracle home directory.
For example, in a UNIX-based environment, the file is located in
$ORACLE_HOME/ctx/admin. In a Windows NT environment, the file is
located in ORACLE_HOME\CTX80\ADMIN.
For more information about the exact location of the file, see the
Oracle8 Server documentation specific to your operating system.
-------------------
-----------------------------------------------------------------------------
*************************
* *
* Linguistic Issues *
* *
*************************
8.1 CTX_PROPER_NAMES Table Obsolete
===================================
In Release 2.3, the CTX_PROPER_NAMES is no longer used by the ConText
Linguistics to process English-text documents that are in all-uppercase
or all-lowercase.
As a result, the ctxprop.dmp file is no longer provided. The ctxprop.dmp
file contained a list of proper names that, when imported into the
CTX_PROPER_NAMES table, enabled the ConText Linguistics case-sensitivity
routines.
If you are upgrading from a previous release and have already imported
ctxprop.dmp into this table, you can delete or truncate
the table.
8.2 Importing Knowledge Catalog/Lexicon Data
============================================
Before ConText can be used to create theme indexes or generate linguistic
output, the Knowledge Catalog/Lexicon data must be imported into the lexicon
table.
For more information, see "7.4 Enabling the
Linguistics".
8.3 Starting ConText Servers for Theme Indexing and Querying
============================================================
Unlike Gist, theme, and theme summary generation, theme indexing and theme
querying do not require ConText servers running with the Linguistics (L)
personality.
Creation of theme indexes is a DDL operation performed by ConText servers
running with the DDL (D) personality. Similarly, theme queries are processed
by ConText servers running with the Query (Q) personality.
For more information about ConText servers, personalities, and the
ctxsrv executable, see "Oracle8 ConText Cartridge Administrator's
Guide".
8.4 Specifying Settings for Linguistic Processing
=================================================
Both the Linguistics and the Theme Lexer use linguistic settings, specified
as setting configurations, to determine:
1) processing for all-uppercase and all-lowercase text or mixed-case text
2) size of theme summaries
3) size and generation method for Gists
ConText provides two predefined setting configurations:
-- GENERIC (mixed-case text)
-- SA (all-uppercase or all-lowercase text)
'GENERIC' is the default predefined setting configuration and is automatically
enabled for each ConText server at start up.
You can create your own custom setting configurations using either of the GUI
administration tools provided in the ConText Workbench. You create custom
setting configurations using the predefined setting configurations as
templates.
You can enable the 'SA' setting configuration or a custom setting
configuration for the current database session/user, using the
SET_SETTINGS_LABEL in the CTX_LING PL/SQL package.
-------------------
NOTE: Successful theme and Gist generation relies on specifying a setting
configuration that matches the size and type of documents to be
processed.
However, theme indexing and theme queries do not rely as heavily on
the settings. As such, the default setting configuration should be
used always for theme indexing/queries.
-------------------
For more information about setting configurations and using the linguistic
settings, see "Oracle8 ConText Cartridge Application
Developer's Guide".
8.5 Changing Settings for Theme Indexing and Queries
====================================================
Because theme indexes are generated on a per column basis and must be
regularly updated/maintained to ensure accurate results for theme queries and
SET_SETTINGS_LABEL only enables a setting configuration for the current
session/user, Oracle Corporation does **NOT** recommend changing the
linguistic settings for theme indexing/queries.
-------------------
NOTE: Once a theme index has been created for a column, the setting
configuration for the current session and any subsequent sessions
should **NOT** be changed.
-------------------
For theme and Gist/theme summary generation, which is performed on a per
document basis and generally requires manual maintenence, enabling a different
setting is not necessary, but is recommended if the default setting
configuration does not generate the desired linguistic
output.
8.6 Obsolete Predefined Setting Configurations
==============================================
The following predefined setting configurations are obsolete and provided only
for backward compatibility:
-- S
-- P
-- PP
-- PS
-- PSP
-- PSA
-- PSAP
If you use any of these obsolete setting configurations in an existing
application, you can continue to use them without any adverse effects; however,
for new applications, you should only use the 'GENERIC' or 'SA' or any custom
setting configurations that you have defined.
-----------------------------------------------------------------------------
**************************
* *
* Fixes/Enhancements *
* *
**************************
9.1 Fixes/Enhancements in Release 2.3
=====================================
403354
Oracle Installer hangs when creating database objects
for CTXSYS.
405408
Error during ConText index creation with Soundex enabled due to incorrect
format for 'stclause' and 'instclause' attributes
in GENERIC WORD LIST Tile.
451530
Queries only return hits from master-detail tables if search terms are
encountered in the first 2000 characters of the text.
458969
Two-step query with large query ID gives incorrect
value in results table.
459036
ctxsrvx core dumps when NLS_LANG is set to AL24UTFFSS
466374
A cursor is left open when executing a one-step query in which the query
expression contains a user-defined function.
474426
Performance problems with struct_query in a two-step query if the datatype for
the textkey is not CHAR or VARCHAR2.
474471
OPTIMIZE_INDEX uses the STORAGE parameters for a view, rather than the STORAGE
parameters specified in the Engine preference.
476799
Fuzzy search with master-detail tables crashes ConText
servers.
478063 (Also fixes 462571)
Access control checks user rather than effective
user.
481502
Internal error encountered, user unable to create a ConText index on a text
table as the owner.
495711
Incorrect results when ID in CTX_QUERY.HIGHLIGHT
is 10 digits or greater.
500035
After loading large amounts of data and calling SYNC, nothing appears in the
DRQ_INPROG table and ConText hangs.
504488
Poor performance for two-step queries that include
structured data
505982
Cannot drop index when server started and there is
pending DML.
509331
Query length over 2000 characters doesn't return error 'Query too complex'
when expected.
510916
Encounter Oracle error --- ORA-04098: TRIGGER 'T1_TR_ROW' IS INVALID AND
FAILED RE-VALIDATION --- when trying to insert into a text table when a
ConText index has been dropped on another text table.
512209
Internal errors encountered when generating themes and gists with user
defined settings.
512698
Don't remove duplicates from DRQ_PENDING for better performance on large
DML batches.
512699
Fold DRQ_INPROG into DRQ_PENDING for better performance
on batch DML.
514404
Cannot create index on theme policy when record contains
policy or preference.
517274
Cannot load documents larger in size than 64K when using automated text loading
(sources and ctxload).
520688 (Also fixes 487974)
HTML filter not indexing some keywords.
521663
Internal error while executing fuzzy match on term, when fuzzy match returns
large number of expansions.
532547
Internal error encountered in ConText log when INSERT and DELETE text using
multiple servers.
569521
ConText query performance degrades as the number of database users
increases.
-----------------------------------------------------------------------------
*************************
* *
* Known Limitations *
* *
*************************
The following section lists known problems that may affect your usage of
ConText, Release 2.3.
10.1 One-Step Queries in PL/SQL Not Supported (344159)
======================================================
ConText, Release 2.3, does not support using one-step queries within
PL/SQL blocks.
If you are using PL/SQL to develop applications, use two-step queries
(CTX_QUERY.CONTAINS) or dynamic SQL (DBMS_SQL package).
The following example illustrates using dynamic SQL in a PL/SQL block to fetch
the score returned by a one-step query for documents containing the word
'test'.
declare
myscore number;
c1 number;
n number;
f number;
stmt varchar2(1024);
begin
stmt := 'select score(0) from docs where contains(text,'test')>0';
c1 := dbms_sql.open_cursor;
dbms_sql.parse(c1, stmt, dbms_sql.v7);
dbms_sql.define_column(c1, 1, myscore);
n := dbms_sql.execute(c1);
loop
f := dbms_sql.fetch_rows(c1);
exit when f = 0;
dbms_sql.column_value(c1, 1, myscore);
dbms_output.put_line('score : ' || myscore);
end loop;
dbms_sql.close_cursor(c1);
end;
10.2 Indexing with Soundex Fails When Many Results Tables are Present (401217)
==============================================================================
If a large number of internal result tables (utilized in one-step queries)
are present during text indexing with Soundex enabled, the index creation will
fail.
-------------------
Suggestion: Before performing text indexing with Soundex, verify that all
unnecessary result tables have been dropped.
-------------------
10.3 One-Step Queries for LONG Columns in Remote Tables Not Supported (436969)
==============================================================================
ConText, Release 2.3, does not support one-step queries on LONG and LONG RAW
columns in remote database tables and views.
10.4 Resume Index Optimization Not Supported
============================================
If index creation or optimization fails during processing,
CTX_DDL.RESUME_FAILED_INDEX can be used to resume the operation from the
failure point; however, additional errors may occur
for index optimization.
-------------------
Suggestion: If index optimization fails during processing, do not use
RESUME_FAILED_INDEX. Instead, fix the reason for the error,
clear the errored request from the error logs, and start
optimization from the beginning.
-------------------
10.5 Scoring for NEAR Operator Inconsistent with Other Operators
================================================================
All the operators in a text query produce scores for query hits based on the
frequency of the occurrences of the query terms, with the exception of the
NEAR operator.
When the NEAR operator is used in a text query, it produces a
score based on the proximity of the two query terms. If the two terms are
adjacent, the score is 100. As the number of tokens between the two terms
increases, the score decreases.
As such, the two scoring methods are inconsistent and, when used together,
will not generally produce meaningful scores.
To avoid this situation, Oracle Corporation suggests that you do not combine
usage of the NEAR operator with other operators.
-----------------------------------------------------------------------------