IBM FileNet Content Engine s Content Based retrieval with IBM Content Search Server

Transcription

1 IBM FileNet Content Engine s Content Based retrieval with IBM Content Search Server Sridhar Satuloori IBM 10/18/2011 Sridhar Satuloori is a FileNet Content Engine developer with IBM in Costa Mesa, California. He is working with the Content Engine development for the past 6 years and has worked on various components of the Content Engine including CBR with CSS server. He also leads the sustaining and support activities for the Content Engine, and is experienced in working with Building Enterprise edition of J2EE application servers. Sridhar holds a masters degree in Computer Science from IIT Roorkee, India. For suggestions or comments on this article, reach out to him at Sridhar.Satuloori@us.ibm.com

2 Introduction 3 Content Search Services 3 Requirements 4 Installing CSE Client 5 Installing CSS server 5 Adding CSS server to a domain 5 Using CE Java API to create a CSS server 8 Configuring an object store for CSS 8 Set the text search indexing language 9 Index Area 9 Enable the object store for CBR 12 CBR enabling the class 13 Enable Dispatcher for IBM Search 14 Indexing Objects 14 By adding a document 15 By selecting documents and creating an indexing job 15 By indexable class 17 Searching for information 17 Basic search 18 Property search 18 Partitioning 18 Date partition 19 String partition 19 XML-based XPath Searches 20 Delete the index and Index Areas 21 2 IBM

3 Introduction Content Engine (CE) supports content-based retrieval (CBR) for documents, annotations, folders, and custom objects. With CBR, you can search a CE object store for objects that contain specific words or phrases embedded in the content or in the properties of objects that have been configured for full-text indexing. CE provides objects textual data and property values that are searchable using IBM Content Search Services (CSS) or the IBM Legacy Content Search Engine. This tutorial shows you how to use CSS for indexing of and searching for CE objects. The tutorial provides step-by-step instructions on how to use the basic CBR features using the CE's Enterprise Manager tool, and it also provides snippets of CE Java API code to use the same feature programmatically. Content Search Services With the P8 5.0 release, CSS is introduced as an index and search server for CE objects. The CSS server uses: Apache Lucene for indexing and search, UIMA (Unstructured Information Management Architecture) for tokenization, and LanguageWare for dictionary processing Full-text indexing and indexing of specific metadata attributes can be configured on a per CE class basis. For example any create or update operation on a given document instance triggers the CE server to evaluate the object s full-text attribute to determine whether to queue the document for indexing. The Indexing Process: The indexing process begins at the CE when CBR-enabled objects, such as documents, are created or updated. The CE stores indexing data for the CE object in indexes created and managed by the CSS servers. Each index is associated with a distinct index area in a CE object store. During the indexing process, the system can write to multiple indexes across the different index areas. When an index's capacity is reached, the index is automatically closed and a new index is created. The CE queries items from the indexing table to identify documents that are queued for indexing, then groups index requests pertaining to the same target index into an index batch. The binary documents in this batch are converted to text, and the entire batch is then submitted to a CSS indexing server. After the CSS index server receives the index batch, the preprocessing functions begin. Preprocessing functions consist of:, 3 IBM

4 Document construction: For XML documents, the XML filtering utility removes any superfluous XML elements from the extracted text. Non-searchable XML elements must be defined as a surplus element in the CSS configuration. Language identification: Ensure accurate processing and optimal performance by specifying a default language for an object store. If one language cannot be definitively identified for the content of an object store, set it to the majority documents language. Identification of the language can be set to automatic to trigger the language identification on an object-by-object basis Tokenization of the document s content and properties: This is the final step of preprocessing. Tokens are created from the extracted text and an index for the document is updated or created in its respective index area The Search Process: Users can submit CBR queries against the full text index with its criteria CBR enabled properties or terms that exist in the content. Search requests are initiated through FileNet Enterprise Manager or other client applications using the CE API and include a full-text expression that is submitted to the CSS search server by the CE subsystem dispatcher. The search server uses word stems, synonyms, and stop words to improve search efficiency. The It searches for and identifies the stem for all word terms included in a full-text search expression. For example, a search for the word running automatically searches for the word run, too. The search server also searches for all defined synonyms in the search expression. For example, if International Business Machines and ibm are defined as synonyms, searching for ibm is equivalent to searching for ibm or International Business Machines. A stop word is a word or phrase that is ignored by the search server to avoid irrelevant search results caused by common expressions. For example, if the word the is defined as a stop word, the phrase The cat and the dog and cat and dog are equivalent. The search server uses these definitions to evaluate the appropriate index and runs the full-text search. The results are returned to the CE dispatcher subsystem which then joins the results with other tables in the query and runs the query. The stop words will not have any effect on the indexing, and they will appear in the indexes created by the CSS server. Requirements This tutorial assumes that you have the following installed and configured on the same machine: Content Engine or higher Content Search Services server or higher and Content Search Engine or higher client installed. This tutorial assumes that you have basic knowledge of the Content Engine and the CE Java API. 4 IBM

5 Installing CSE Client A CE installation does not include the components needed for the text extraction required for indexing binary documents (such as Microsoft Word and Excel). To enable the CSS server to extract the text from binary documents, you must execute the CSE client installer on the platform where the CE is deployed. The CSE client installer adds the correct INSO files for that platform, which are required for the text extraction. The CSE client installer also updates the CSS client files that are bundled with the CE. After a successful CSE installation, the CE size grows by 10 to 15Mb based on the platform. The CE needs to be bootstrapped and deployed. After a successful deployment, the CE Ping page shows the INSO version installed. Installing CSS server The CSS server is a scalable server for document indexing and search. Each CSS instance can be used for either indexing or search or for both tasks. The CSS server can be installed as a single server that can be used for both indexing and search. In a multi-css server installation, you can configure the CE server to use some CSS servers for indexing, some for search, and some for both indexing and search. The recommended approach is to deploy multiple CSS server instances and assign each one to do only indexing or search tasks. The CSS server installer also lets you install multiple CSS servers on the same host. In addition to the host name and port number, the CSS installer prompts for the seed to generate the authentication token. This token is required by the CSS server to communicate with it. After a successful installation, the installer shows the authentication token. The authentication token can also be printed using the CSS server configtool command. Adding CSS server to a domain After installing the CSS server, the next step is to add the CSS server to the CE Domain. Each CSS server is associated with a particular site and can be used by any object store within that site. 1. Log on to Enterprise Manager as the GCD Administrator 2. Right-click Enterprise Manager [domain]>select Properties 3. On the IBM Content Search Servers tab, click Create>Clicking Create starts the CSS server create wizard 4. Click Next 5 IBM

6 5. Enter the display name Tutorial_CSS_Server for the CSS server in the server identification screen 6. Click Next 7. Select Initial Site as the site you want this server to be associated with 8. At the Create an IBM Content Search Services Server window, enter the following server settings and click Next Host name - Hostname or IP address of the CSS server. Port - The port number that the CSS server is listening. This can also be found in the jetty.xml file under the config directory of CSS server installation. Authentication token - The authentication for the CSS server. 6 IBM

7 Note: This can also be obtained by running the configtool command, as follows: C:\Program Files\IBM\Content Search Services\CSS Server\bin>configTool.bat printtoken -configpath "c:\program Files\ibm\Content Search Services\CSS Server\config" The authentication token is printed below. This token is used to communicate with the server. Store the token if applicable. DVx8bw== The encryption key is printed below. This key is used to encrypt the password during text index backup and restore operations. Store the key if applicable. c8dtrhjeyisvb/zfdfj/+w== Mode Each CSS Server can be configured for either indexing or search or for both. Select the server mode IndexAndSearch. This tutorial uses the same server for both indexing and search. Status - Select Enabled. This status will be automatically changed to Unavailable if the CE detects that the CSS server is not responding. 9. Enabling SSL support lets the CE server communicate with the CSS server using SSL. For this tutorial we are not using SSL, so click Next 10. Review the data entered 11. Click Finish. 7 IBM

8 12. After you click Finish, the CE server validates all the values entered and communicates with the CSE server to make sure it is up and running. Then Enterprise Manager prompts that the IBM Search Server object has been created successfully. Using CE Java API to create a CSS server 1. Get the domain Object for CEDomain using connection to the CE server Domain domain = Factory.Domain.fetchInstance(Factory.Connection.getConnection(" ocalhost:9080/wsi/fncews40mtom/"), "CEDomain", null); 2. Create the TextSearchServer Instance using the Factory CmTextSearchServer tss = Factory.CmTextSearchServer.createInstance(domain); 3. Set the hostname, port numer and authentication token. tss.set_displayname("tutorial_css_server"); tss.set_textsearchserverhost("localhost"); tss.set_textsearchserverport("8191"); tss.set_textsearchcredential("dvx8bw==".getbytes()); 4. Set the tss server in the Index and search mode. tss.set_textsearchservermode(textsearchservermode.index_and_search); 5. Mark the server as enabled tss.set_textsearchserverstatus(textsearchserverstatus.enabled); 6. Add this server to the site. tss.set_site(site); 7. And save tss.save(refreshmode.refresh); Configuring an object store for CSS An object store is a database repository for storing objects (such as documents, folders, and business objects) and the metadata defining an object's classes and properties. Each object store has a database containing metadata such as property values for documents, folders, and other objects. The document content is located in either the object store database (a database storage area) or in another storage area associated with the object store. In order for an object store to be enabled for search, you have to configure the object store with index areas and enable one of the object store's classes for CBR. When the CE server indexes documents on the CSS server, the full text indexes created by the CSS server gets stored in index areas. 8 IBM

9 Note: An index area is a file system directory that contains indexes created by the CSS server. Each object store can have more than one index area and each index area can have multiple indexes. Set the text search indexing language Identifying the text search indexing language for an object store is important to ensure accurate text processing in the CSS server and for optimal indexing performance. If the object store contains objects that belong to more than one language, set the text indexing language to the language of the majority of documents. 1. In the Enterprise Manager navigation pane, right-click on the object store>click Properties 2. Click the CBR IBM Search tab. 3. Select en (English) as the indexing language Using the CE Java API Retrieve the object store TutoralObjectStore associated with the Domain CEDomain. Set the text search indexing language to en. Specifying the language of the objects in the CE skips the language identification step in the CSS server while indexing the document. Automatic language identification might incorrectly identify a language or might fail if the document is very small in size. For production systems, setting the text search indexing language to auto may not work as expected and is not advisable as it will impact the performance of the indexing. ObjectStore objectstore = = Factory.ObjectStore.fetchInstance(domain, "TutoralObjectStore", null); objectstore.set_textsearchindexinglanguage( en ); objectstore.save(refreshmode.refresh); Index Area An index area is a file system directory that contains CSS indexes. Each object store can have multiple index areas and each index area can have multiple indexes. The index contains the indexing information for the objects that belong to the same indexable base class or subclasses of the base class. The text in the content elements and in the CBR-enabled properties of an object is stored as one entry in an index. Consequently, a full-text search returns one search result for each object regardless of the number of times that the object text matches the search criteria. 9 IBM

10 Both an index area and an index have a status property that controls whether index information can be changed or added. The status does not control the accessibility of index information for CSS servers. Index information is always available for searches. The possible statuses are OPEN, FULL, CLOSED, and, for index areas, STANDBY. To add an index area to an object store: 1. In the Enterprise Manager navigation pane, expand the object store (TutoralObjectStore), right click on the Index areas folder and select Index Area. The Index Area Creation Wizard displays 2. Click on Next 3. Select IBM Search Server Index Area 4. Click Next 5. Enter the index area name as Tutorial_IndexArea. 6. Click Next 10 IBM

11 7. Enter the Root Directory Path as \\sridhar\collections. Make sure that the path exists. Keep the other values unchanged. 8. Click Next 4. Verify the values and click Finish. Using the CE Java API CmTextSearchIndexArea cia = Factory.CmTextSearchIndexArea.createInstance(os); cia.set_resourcestatus(resourcestatus.open); cia.set_descriptivetext("tutorial_indexarea"); cia.set_displayname("tutorial_indexarea"); String rootdir = "\\\\sridhar\\collections "; try{file f = new File(rootDir); if (!f.exists()) f.mkdirs(); } catch (Exception e) {e.printstacktrace();} cia.set_rootdirectorypath(rootdir); // Following are the optional properties cia.set_site(os.get_site()); 11 IBM

12 cia.set_maxindexes(new Integer(MAX_INDEXES)); cia.set_maxobjectsperindex(new Double(MAX_OBJECTS_PER_INDEX)); cia.set_resourcestatus(resourcestatus.open); cia.save(refreshmode.refresh); Enable the object store for CBR To run CBR on an object store, the object store has to be enabled for CSS services. Enabling CSS lets the CE server index the documents to the configured CSS server, and searches the indexes created by the CSS server. If both the IBM Legacy Content Search Engine and CSS are enabled, then the CE server initiates the object store migration to CSS. During the migration process, the CE objects will be indexed into both search engines. 1. In the Enterprise Manager navigation pane, right-click on the object store (TutoralObjectStore) > click Properties. 2. Click the CBR IBM Search tab. 3. Check IBM Content Search Services Enabled. Using the CE Java API Fetch the ObjectStore object and set TextSearchEnabled to TRUE. objstore.set_textsearchenabled(boolean.valueof(true)); objstore.save(refreshmode.no_refresh); 12 IBM

13 CBR enabling the class The only objects that can be indexed in a CE object store are the objects that belong to a CBRenabled class. Setting the CBR enabled flag on the object store class allows full-text indexing of the objects in that class. A class and its subclasses can be marked for CBR. For example, you can search the content of Document objects if you set the Document class to be CBR-enabled. CBR enabling a class lets the newly created objects of that class to be indexed. An Index job needs to be created to index the objects that were existed before enabling the CBR on the class. To set the CBR-enabled status for a class: 1. From the Enterprise Manager navigation pane, expand the object store (TutoralObjectStore) node. 2. Right-click on the Document Class definition and click Properties. 3. In the General tab, check the CBR Enabled check box. 4. Click OK. Using the CE Java API Fetch the ClassDefinition object and set IsCBREnabled to TRUE. ClassDefinition doccd = Factory.ClassDefinition.fetchInstance(objStore, ClassNames.DOCUMENT, null); doccd.set_iscbrenabled(boolean.true); doccd.save(refreshmode.refresh); 13 IBM

14 Enable Dispatcher for IBM Search The CE subsystem dispatcher groups the index requests to form an index batch. The target index is the same for all index requests in a batch. The dispatcher should be enabled for the documents to be indexed into CSS indexes. The CBR dispatcher can be enabled at the domain, site, virtual server, and server levels. Setting the value at a lower level (server is the lowest, domain the highest) overrides the setting at a higher level. 1. In Enterprise Manager, right-click Enterprise Manager [domain], select Properties, and on the IBM Content Search Servers tab, click Create. 2. On the IBM Search Configuration tab, check Enable Dispatcher Using the CE Java API Get the list of SubsystemConfigurations. From this list find the CmTextSearchConfiguration. Set the DispatcherEnabled to true on the CmTextSearchConfiguration SubsystemConfigurationList sclist = domain.get_subsystemconfigurations(); CmTextSearchConfiguration tsc = null; // find the Text Search Config object from domain for (int i = 0; i < sclist.size(); i++) { if ( sclist.get(i) instanceof CmTextSearchConfiguration ) { tsc = (CmTextSearchConfiguration)sclist.get(i); break; } } tsc.set_dispatcherenabled(boolean.true); domain.save(refreshmode.refresh); Indexing Objects The Indexing of a CE object involves several steps from the CE to the CSS server. The indexing process starts when a document or properties are submitted for indexing by creating or updating the CBR-enabled object. The CE server generates an index request if the CBR-enabled object is created or updated. The CE server creates an index job if a user tries to index the CBR-enabled class or object. Re-indexing an index from the index area also creates an index job. For all of the objects that are part of an index request or index job, CE determines the correct index area and the index for 14 IBM

15 these objects to be indexed into. Next, CE groups the index requests that are targeted for the same index into a single batch. All of the index requests in a batch will be targeted for the same index. When the CBR dispatcher gets activated, it picks up a batch and starts working on the index requests in this batch. Indexing is an asynchronous operation and will be executed when the index dispatcher thread is available for indexing. For the index requests that contain the nontextual documents, the CBR dispatcher launches a thread to extract the text from it. Any nontextual documents must be converted to text before submitting them to the CSS server. CE uses the Oracle Outside In Search Export product for extracting the text from the non-textual documents. After the text is submitted to the CSS indexing server with automatic language identification in the object store properties, then the CSS (index) server tries to identify the language of the text from the text of the document. A CSS index server can misidentify the text language for an object, especially when the object has few words. You can find an object with a misidentified text language by exact match searches but not by language-aware searches. In particular, a word stem search that a search server performs automatically cannot be found for an object with a misidentified language. After language identification, the CSS server creates tokens for the text document based on a language-aware analysis of the text. Word stems and other language constructs are identified. Once the tokens are created, the index server updates the index entry for the CE object into the target index. By adding a document For an object store that is CBR- enabled, the CE server creates the index request for every new or updated object whose class is CBR-enabled. Users can see the index request in the indexing queue of FileNet Enterprise Manager. Indexing requests will be deleted by CE soon after the document is indexed. Users can re-index the document in the FileNet Enterprise Manager content pane by: right-click on the object >clicking All Tasks > Index for Content Search. An index job is created. By selecting documents and creating an indexing job Another way of indexing a document is to select the documents and create an index job. This Bulk Operations action will create an index job that can be managed through the Index Jobs Manager. This index job contains the index requests for each object. These index jobs can be viewed from the Object store -> Index Jobs managements view. This view also provides the list of index requests that are associated with the index job. 15 IBM

16 1. In the Enterprise Manager content pane, select multiple objects> rightclick>choose Multiselect Operations 2. Check Index for Content Search 3. Click Apply>OK Using the CE Java API Using the CE Java API, IndexJobItemList is created with the number of IndexJobSingleItem that contains the CE objects that need to be indexed. A new IndexJob for the object store will be assigned with the IndexJobItemList that needs to be worked on. Document docwithcontent = Factory.Document.createInstance(objStore, docclassname); ContentElementList cel = Factory.ContentElement.createList(); ContentTransfer ctnew = Factory.ContentTransfer.createInstance(); String text ="This is the content element for the Tutorial"; ByteArrayInputStream is = new ByteArrayInputStream(text.getBytes()); ctnew.setcapturesource(is); ctnew.set_contenttype("text/plain"); cel.add(ctnew); docwithcontent.save(refreshmode.refresh); IndexJobItemList itemlist = Factory.IndexJobItem.createList(); IndexJobSingleItem item = Factory.IndexJobSingleItem.createInstance(); item.set_singleitem(docwithcontent); itemlist.add(item); IndexJob indexjob = Factory.IndexJob.createInstance(objectStore); indexjob.set_indexitems(itemlist); indexjob.save(refreshmode.refresh, null); while (indexjob.get_jobstatus() == IndexJobStatus.IN_PROGRESS indexjob.get_jobstatus() == IndexJobStatus.PENDING) { waitsecs(10); indexjob.refresh();} 16 IBM

17 By indexable class You can also index the class that is enabled for CBR. Indexing the class creates an index job with an index item for each CE object of the Indexable class type in the object store. Using the CE Java API IndexJobItemList is created with the IndexJobClassItem for the class that the user wants to reindex. A new IndexJob for the object store will be assigned with the IndexJobItemList that needs to be worked on. IndexJobItemList itemlist = Factory.IndexJobItem.createList(); IndexJobClassItem classitem = Factory.IndexJobClassItem.createInstance(); classitem.set_classdefinition(factory.classdefinition.getinstance(objectstore, GuidConstants.Class_Document)); itemlist.add(classitem); IndexJob indexjob = Factory.IndexJob.createInstance(objectStore); indexjob.set_indexitems(itemlist); indexjob.set_descriptivetext("indexing the class "+ClassNames.DOCUMENT); indexjob.save(refreshmode.refresh); while (indexjob.get_jobstatus() == IndexJobStatus.IN_PROGRESS indexjob.get_jobstatus() == IndexJobStatus.PENDING) { try{ Thread.sleep(30*1000); }catch(exception e){} indexjob.refresh(); } Searching for information The process of searching for object text begins with the submission of a CBR query and ends with the return of the search results. A CBR query includes a CONTAINS function call to perform a full-text search. CSS is based on the Lucene text search engine, so the search expression syntax must generally conform to Lucene syntax. It additionally supports XPath-based searching for XML documents. When a CBR query is submitted, CE selects a search server to run the full-text search for the query. The default search server selected is the dual-mode server that most recently updated the index that is relevant for the full-text search. If the default server is not eligible to run the search, CE assigns the search request to a randomly selected available search server. Based on the search expression entered in the CONTAINS clause, the CE server identifies the indexes to search for this expression. Since all of the indexes are accessible to all of the search servers, the CE server submits the CBR query for the selected search server. The search server identifies the word stems for the terms in the full-text search expression and it also identifies any synonyms for the terms in the full-text search expression. The search server also identifies any stop words in the full-text search expression and removes them from the expression. 17 IBM

18 The search server reads the indexes that were passed by the CE server and runs the full-text search. The search results are passed back to the CE server. These full text results from the CSS server will be joined with other tables in the CBR query, and the final results will be sent to the client that issued the search query. Basic search The heart of a CBR query is the CONTAINS clause in a SQL statement. Following is an example that searches objects of type Document for the words, lion and tiger, in the objects' content. SELECT d.this FROM Document d INNER JOIN ContentSearch c ON d.this = c.queriedobject WHERE CONTAINS(d.*,'lion AND tiger') Using Enterprise Manager, users can submit a CBR query to search for object text in a single object store. In the Enterprise Manager navigation pane, expand the object store that you want to search>right-click on Search Results Click View > SQL View. Enter the above SQL statement for the query Click OK to submit the query. The search will be run on the CSS server, and the CE server combines the results and sends the results to Enterprise Manager. Property search CE allows users to search for words in String properties if the String properties are specifically enabled for CBR. The class definition of the properties should be enabled before you enable its properties. A String property can be enabled for CBR by modifying its Property Definition from the class. The following example searches the documents for the word, lion, in the CBR-enabled property, animal. SELECT d.this FROM Document d INNER JOIN ContentSearch c ON d.this = c.queriedobject WHERE CONTAINS(d.animal,'lion') Partitioning CE can do index partitioning based on the partitioning property value. Index partitioning is the way to group the indexing information for the objects whose partitioning property value is the same. Indexing partitioning improves the performance of the CBR search when the search criteria contain the partitioning criteria by including only indexes that have partitioning information. Otherwise performance may be worse because it has to search more number of collections For a CBR search to work on the partitions, the query should contain the partition property in the WHERE clause. 18 IBM

19 CE supports partitioning based on dates, and partitioning based on a string. Date partition Date-partitioned indexes have an associated range of date values for the partition property of the objects indexed. For example, the associated date range for an index might be a two month period such as January 1, 2010 to March 1, The date range is defined by the Start Date and End Date properties of the index. The indexed objects have a partition property value greater than or equal to the Start Date value and less than the End Date value. When a new document containing a partitioning property is indexed, the value of the property is compared to the indexes of an index area. If the value is within the date range of an index and if the index is not full, the document is indexed into that index. If the partitioning property value of the document does not fit within the date ranges of the existing indexes, a new index is created. The new index Start Date and End Date property values determined by the object store Interval property and the partitioning date value of the document. The document is then indexed into the new collection. The following query searches for the words, lion and tiger, in documents that are created after April 06, 2011, 09:45AM. SELECT d.this FROM Document d INNER JOIN ContentSearch c ON d.this = c.queriedobject WHERE CONTAINS(d.*,'lion AND tiger') AND d.datecreated >= T09:45:00 String partition To search CSS index partitions, the WHERE clause of a query must contain conditions on the string property; otherwise, all indexes will be searched. For example, assume that a class has a custom property called "tenant" on which to partition documents, and the object store on which the class resides is configured to use "tenant" as the partitioned property, then the following query statement invokes a search on partitioned indexes. SELECT FROM Document D INNER JOIN ContentSearch CS ON D.This=CS.QueriedObject WHERE CONTAINS(*,'lion') AND D.tenant= IBM 19 IBM

20 1. In the Enterprise Manager navigation pane, right-click on the object store (TutoralObjectStore) and click Properties. 2. Click the CBR IBM Search tab. 3. In the Partitioning Settings, select the String Property name for the string partition. 4. For date partitioning, select the Date Property name and the Interval. XML-based XPath Searches A CBR query's CONTAINS function accepts an XPath-based expression for searching XML content. When queried, the XPath-based search expression is sent to the CSS server for processing. The CSS server implements only a subset of the XPath specification. CBR XPath-based searches can search only on CE Document and Annotation objects with one content element with a mime type as text/xml or application/xml. It supports only one XML node as part of the search. CBR searches by default assume that the XML encoding for an XML document is UTF-8, when it is not specified in the XML. In the following example, contains("foo"]' search expression is passed to the CONTAINS function: SELECT d.this FROM Document d INNER JOIN ContentSearch c ON d.this = c.queriedobject WHERE CONTAINS(d.*, '@xmlxp:''/listofelements/element[. contains("foo"]''') Consider the following XML, <?xml version="1.0" encoding="utf-8"?> <ListOfElements> <Element received_date=" ">foo</element> </ListOfElements> The above XML is used in the following XMLXP search expressions. To search the exact node the XMLXP expression should be contains("foo")]''. For search everything in a contains("foo")]''. To find multiple terms with an optional term under the same element /ListOfElements[. contains("foo %bar")]. 20 IBM

21 Delete the index and Index Areas In some instances, you might want to delete indexes and index areas. The CE server does not allow you to delete any non-empty indexes and index areas. To delete an index, you must delete the content in the indexes and then delete the index. Once all of the indexes in the index area are deleted, you can delete the index area. This can be achieved automatically by disabling the CBR enabled flag at the root level class and propagating it to all the subclasses. Disabling the CBR enabled flag does not delete the indexing information from the indexes. It only stops the full text indexing of new documents and updates to any of the existing documents. When disabling the CBR enabled flag on the root class, you should propagate the changes to all the subclasses. Keeping any subclasses as CBR-enabled will not allow the indexes to be deleted. After the CBR enabled flag is unchecked using Enterprise Manager, you have to start a reindexing job on the root class. The re-indexing job must be run on the root class, not on the subclasses, for all of the indexing information to be deleted. Once all the index information is deleted, the CE server deletes the indexes from the index area. You can delete the index area after all the indexes are deleted. 21 IBM