DDML, a language based on XML (Extensible Markup Language), allows you to logically define the entities you want to add to the Precise schema, such as tables, views, indexes, foreign keys, and all other required components. It covers the common entities available in most popular DBMSs.
After you have defined all database entities in DDML, you must run the DDML creation script to physically create the entities in the database.
General DDML document format
The general format of a DDML document looks as follows:
| Tag | Description |
|---|---|
<tables-definition> | Root element of a DDML document. Its children are the main database entities:
|
<table-definition> | Includes the table-level attributes. Its children are the If a table is a statistics table, meaning means that the type attribute has the value STATISTICS, the |
<ddl-definition> | Includes ddl-level attributes. |
<view-definition> | Includes view-level attributes. |
<tables-definition> tag
Root element of the DDML document.
| Attribute | Definition |
|---|---|
product | Required. Holds the product short name (product shortcut) consisting if two characters that define the product. In this case, three custom-defined products are available:
|
<table-definition> tag
Holds all of the information included in a single table.
| Attribute | Definition |
|---|---|
name | Required. Holds the table name. |
type | Required. Specifies the table type and can hold one of the following values:
|
pctfree | Optional. Affects only Oracle and is developed as Can have a value between 0 and 99. If the PMDB is a Microsoft SQL Server database, this attribute is transformed to |
pctused | Optional. Affects only Oracle and is developed as PCTUSED pctused. Can have a value between 0 and 99. |
initrans | Optional. Affects only Oracle and is developed as INITRANS initrans. Can have a value between 1 and 255. |
maxtrans | Optional. Affects only Oracle and is developed as MAXTRANS maxtrans. Can have a value between 1 and 255. |
oracle-storage-clause | Optional. Affects only Oracle and is developed as
|
oracle-additional-clause | Optional. Added to support any other Oracle features that cannot be defined in an Oracle storage clause. For example: NOLOGGING |
filterable | Required for statistics tables (type=STATISTICS). If one or more columns are not relevant or needed in the PMDB, set this attribute to TRUE. If a statistics table is filterable and some columns are specified as not needed in the load or summary control files, these columns are not loaded or summarized. |
The <table-definition> tag can have the following children:
<column-definition><index-definition><foreign-key-definition>
| Additional Child | Definition |
|---|---|
<summary-hour> | Optional. Instructs to define an hour-level summary table for this table. Used for time slice statistics tables. The name of the summary table is specified by the name attribute (required). The summary table name should follow the naming conventions specified in Naming conventions. |
<summary-day> | Optional. Instructs to define a day-level summary table for this table. The name of the summary table is specified by the name attribute (required). The summary table name should follow the naming conventions specified in Naming conventions. |
<summary-week> | Optional. Instructs to define a week-level summary table for this table. The name of the summary table is specified by the name attribute (required). The summary table name should follow the naming conventions specified in Naming conventions. |
<summary-month> | Optional. Instructs to define a month-level summary table for this table. The name of the summary table is specified by the name attribute (required). The summary table name should follow the naming conventions specified in Naming conventions. |
<ddl-definition> tag
Holds DDL (Data Definition Language) and DML (Data Manipulation Language) statements that can be performed during installation or uninstallation, such as stored procedures.
| Attribute | Definition |
|---|---|