PL/SQL Packages and Types Reference 10g Release 1 (10.1) Part Number B10802-01 |
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The DBMS_XDBT
package provides a convenient mechanism for administrators to set up a CONTEXT
index on the Oracle XML DB hierarchy. The package contains procedures to create default preferences, create the index and set up automatic synchronization of the CONTEXT
index
The DBMS_XDBT
package also contains a set of package variables that describe the configuration settings for the index. These are intended to cover the basic customizations that installations may require, but is by no means a complete set.
This chapter contains the following topics:
The DBMS_XDBT
package can be used in the following fashion:
DROPPREFERENCES Procedure
procedure.CREATEPREFERENCES Procedure
procedure.CONTEXT
index using the CREATEINDEX Procedure
procedure.CONFIGUREAUTOSYNC Procedure
procedure.The DBMS_XDBT package can be customized by using a PL/SQL procedure or an anonymous block to set the relevant package variables, configuration settings, and then execute the procedures. A more general approach would be to introduce the appropriate customizations by modifying this package in place, or as a copy. The system must be configured to use job queues, and the jobs can be viewed through the USER_JOBS
catalog views. This section describes the configuration settings, or package variables, available to customize the DBMS_XDBT
package.
Parameter | Default Value | Description |
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Name of the stoplist. |
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List of stopwords, in excess of |
This procedure sets up jobs for automatic SYNCs of the CONTEXT
index.
DBMS_XDBT.CONFIGUREAUTOSYNC;
USER_JOBS
catalog viewsAutoSyncPolicy
can be set to choose an appropriate synchronization policy.The synchronization can be based on one of the following:
Sync Basis | Description |
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The SYNC is triggered when the number of documents in the pending queue is greater than a threshold (See the MaxPendingCount configuration setting). The pending queue is polled at regular intervals (See the CheckPendingCountInterval configuration parameter) to determine if the number of documents exceeds the threshold. |
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The SYNC is triggered at regular intervals. (See the SyncInterval configuration parameter). |
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A combination of both of the preceding options. |
This procedure creates a user datastore preference for the CONTEXT
index on the XML DB hierarchy.
DBMS_XDBT.CREATEDATASTOREPREF;
d
atastore preference can be modified; see the DatastorePref
configuration setting.USER
datastore procedure also filters the incoming document. The DBMS_XDBT
package provides a set of configuration settings that control the filtering process.SkipFilter_Types
array contains a list of regular expressions. Documents with a mime type that matches one of these expressions are not indexed. Some of the properties of the document metadata, such as author, remain unindexed.
NullFilter_Types
array contains a list of regular expressions. Documents with a mime type that matches one of these expressions are not filtered; however, they are still indexed. This is intended to be used for documents that are text-based, such as HTML, XML and plain-text.This procedure creates a NULL
filter preference for the CONTEXT
index on the XML DB hierarchy.
DBMS_XDBT.CREATEFILTERPREF;
FilterPref
configuration setting.USER
datastore procedure filters the incoming document; see CREATEDATASTOREPREF Procedure
for more details.This procedure creates the CONTEXT
index on the XML DB hierarchy.
DBMS_XDBT.CREATEINDEX;
IndexName
configuration setting.LogFile
configuration parameter to enable ROWID
logging during index creation.IndexMemory
configuration parameter to determine the amount of memory that index creation, and later SYNCs, will use.This procedure creates a BASIC lexer
preference for the CONTEXT
index on the XML DB hierarchy.
DBMS_XDBT.CREATELEXERPREF;
lexer
preference can be modified; see LexerPref
configuration setting. No other configuration settings are provided.MultiLexer
preferences are not supported.This procedure creates a set of default preferences based on the configuration settings.
DBMS_XDBT.CREATEPREFERENCES;
This procedure creates a section group for the CONTEXT
index on the XML DB hierarchy.
DBMS_XDBT.CREATESECTIONGROUPPREF;
SectiongroupPref
configuration setting.AUTO_SECTION_GROUP
or the PATH_SECTION_GROUP
; see the SectionGroup
configuration setting.This procedure creates a stoplist for the CONTEXT
index on the XML DB hierarchy.
DBMS_XDBT.CREATESTOPLISTPREF;
StoplistPref
configuration setting.StopWords
array is a configurable list of stopwords. These are meant to be stopwords in addition to the set of stopwords in CTXSYS.DEFAULT_STOPLIST.
This procedure creates a BASIC_STORAGE
preference for the CONTEXT
index on the XML DB hierarchy.
DBMS_XDBT.CREATESTORAGEPREF;
StoragePref
configuration setting.CONTEXT
index; see the IndexTablespace
configuration setting.I_INDEX_CLAUSE
uses key compression.This procedure creates a wordlist preference for the CONTEXT
index on the XML DB hierarchy.
DBMS_XDBT.createWordlistPref;
WordlistPref
configuration setting. No other configuration settings are provided.FUZZY_MATCH
and STEMMER
attributes are set to AUTO
(auto-language detection)This procedure drops any previously created preferences for the CONTEXT
index on the XML DB hierarchy.
DBMS_XDBT.DROPPREFERENCES;