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Chapter 15 JDBC Backing Store Setup : Cases That May Need Additional Setup

Cases That May Need Additional Setup
This section explains some cases that may require additional setup configuration.
Ontology Identifiers that Exceed the DBMS Maximum Column Length
Entity names and entity property names are used by backing store scripts to generate database table and column identifiers.
DBMSs put different limits on the length of a database identifier name. For example, in Oracle the maximum length is 30 characters, and in SQL Server the limit is 128 characters.
Generated database identifiers are longer than the TIBCO BusinessEvents identifiers because they contain characters in addition to the TIBCO BusinessEvents identifier.
You can handle long identifier issues in either of the following ways (or a combination of these ways).
Letting the Utility Generate Short Aliases for Table Names
You can allow the be-jdbcdeploy utility to generate short aliases for long names. You can also edit those names and rerun the utility. For details see Task J, Check the Aliases File and Modify Aliases as Desired.
Note that alias file entries are also generated for another reason. See Ontology Identifiers that Use Database Key Words.
Specifying Short Table Names in the CDD File
You can avoid the problem of long entity type names before you begin to configure the backing store by specifying short database identifiers using the CDD Table Name setting.
The advantage of this method is that you can choose meaningful names before running the be-jdbcdeploy utility. The disadvantages are that you may not know ahead of time which entities require short names, and you must also ensure that the table names you specify are unique across all entities in the ontology.
If you do not specify table names, and entity names are repeated, on the other hand, the generated table names are appended with dollar ($) characters as necessary, for example, D_ORDER, D_ORDER$, D_ORDER$$ and so on.
See Configure the CDD for Special Cases (As Needed) for details.
Ontology Identifiers that Use Database Key Words
As well as database names that are too long, ontology terms that are key (reserved) words in your DBMS product must also be mapped to an alias. If errors occur when you run the SQL scripts due to key word clashes, examine the errors and add the appropriate words to the key word mapping file.
A provided file (BE_HOME/bin/dbkeywordmap.xml) ships with some basic mappings: start, end, schema, mode, and index. You can use it as a model.
Unlike the Aliases file, the key word mapping file is not a project-specific file. It is intended to be generally useful across different projects. However, keyword mappings are also added to the aliases file when you run the SQL scripts, so you can also provide project-specific aliases for the generic mappings, if you want to.
The procedures are explained in the task sections within the section JDBC Backing Store Database Setup Utility Tasks.
String Properties that Exceed the DBMS Maximum Column Length
The default column size for String type attributes is 255 characters. If you expect the data length of an entity property to exceed that value, then in the CDD file set the Max Length field for each entity’s properties The utility changes the data type of String attributes with long lengths to CLOB, as appropriate.
See Configure the CDD for Special Cases (As Needed) for details.
Excluding Entities from the Backing Store
You do not have to use the backing store for all entities. In the CDD file you can specify entities for which you do not want to use the backing store.
See Configure the CDD for Special Cases (As Needed) for details.

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