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COSMOS CMDBf Query to SQL Mapping

Revision as of 23:04, 26 May 2008 by Hkyleung.ca.ibm.com (Talk | contribs) (→‎Mapping)

Overview

MDRs and federating CMDBs support CMDBf query services, which accepts queries in CMDBf query format. The query service interprets the CMDBf query and queries the underlying data store for data. We can safely assume that no database or application would understand the CMDBf query today, as it is a new standard. So the MDR or ferderating CMDB would need to translate the CMDBf query to another query language, or invoke an appropriate method call of the application that serves the data for the MDR.

It is common to have data stored in relational databases. It is useful to come up with a set of guidelines for mapping CMDBf queries to SQL, and vice versa.

CMDBf query only supports a subset of SQL query capabilities, and there are CMDBf queries that are difficult to be done with SQL. The goal is to cover the basic queries that allows a two-way mapping between CMDBf query and SQL.

Schema

The examples below will use the following two schema definitions. These two schemas are equivalent but the CMDBf queries may be different.

Schema 1

Schema1.jpg

Schema 2

Schema2.jpg

Both schemas are for modeling relationships between operating system instances (OS) with computers. An operating system instance can be installed on one computer. In the first schema, the relationship is represented by the foreign key from the OS table to the Computer table. In the second schema, the relationship is represented by a separate table.

Mapping

  • namespace: database or schema
  • recordConstraint/recordType/@localName: table name
  • recordConstraint/propertyValue/@localname: column name
  • recordConstraint/propertyValue/*: predicates in the where clause
    • a predicate is in the form <column_name> <operator> <value>
    • operators supported: =, <, >, <=, >=, contains, like, isNull
    • the negate operation can be applied on a predicate
    • When there are more than one predicates, they can be logically AND-ed or OR-ed, using the matchAny attribute. (A combination of AND and OR is not allowed.)
    • The value on the right side of the operator cannot be a variable or a column name. i.e. the operator can only operate on a constant.
  • SQL lets you select a subset of the table columns to be included in the query result. The response filtering can be done by:
    • suppressFromResult attribute of itemTemplate or relationshipTemplate: columns from tables representing the items or relationships will not be part of the query result.
    • recordConstraint/contentSelector/selectedProperty/@localName: columns to include.
  • relationshipTemplate can be used to specify a table JOIN.

Queries

Find all computers

SQL: select * from Computer

CMDBf Query: 

<s:query xmlns:s="http://cmdbf.org/schema/1-0-0/datamodel">
   <s:itemTemplate id="computers">
      <s:recordConstraint >
         <s:recordType namespace="http://www.eclipse.org/cosmos/examples" localName="Computer" >
         </s:recordType>
      </s:recordConstraint>
   </s:itemTemplate>
</s:query>

Find computers with model equals "A123"

SQL: select * from Computer where model=A123

CMDBf Query: 

<s:query xmlns:s="http://cmdbf.org/schema/1-0-0/datamodel">
   <s:itemTemplate id="computers">
      <s:recordConstraint>
         <s:recordType namespace="http://www.eclipse.org/cosmos/examples" localName="Computer" >
         </s:recordType>
         <s:propertyValue namespace="http://www.eclipse.org/cosmos/examples" localName="model" >
         <s:equal>A123</s:equal>
         </s:propertyValue>
      </s:recordConstraint>
   </s:itemTemplate>
</s:query>

Find computers with 2G memory or more

SQL: select * from Computer where memory > 2000

CMDBf Query: 

<s:query xmlns:s="http://cmdbf.org/schema/1-0-0/datamodel">
   <s:itemTemplate id="computers">
      <s:recordConstraint>
         <s:recordType namespace="http://www.eclipse.org/cosmos/examples" localName="Computer" >
         </s:recordType>
         <s:propertyValue namespace="http://www.eclipse.org/cosmos/examples" localName="memory" >
         <s:greater>2GB</s:greater>
         </s:propertyValue>
      </s:recordConstraint>
   </s:itemTemplate>
</s:query>

Find computers with serial number XYZ

SQL: select * from Computers where serialnum=XYZ

CMDBf Query: 

<s:query xmlns:s="http://cmdbf.org/schema/1-0-0/datamodel">
   <s:itemTemplate id="computers">
      <s:recordConstraint>
         <s:recordType namespace="http://www.eclipse.org/cosmos/examples" localName="Computer" >
         </s:recordType>
         <s:propertyValue namespace="http://www.eclipse.org/cosmos/examples" localName="serialnum" >
         <s:equal>XYZ</s:equal>
         </s:propertyValue>
      </s:recordConstraint>
   </s:itemTemplate>
</s:query>

Use InstanceIdConstratin?!

Find computers running Windows and their OS instances

SQL: select * from Computer, OS where OS.computer_serialnum=Computer.serialnum and OS.type=WINDOWS

CMDBf Query: 

<s:query xmlns:s="http://cmdbf.org/schema/1-0-0/datamodel">
   <s:itemTemplate id="computers">
      <s:recordConstraint>
         <s:recordType namespace="http://www.eclipse.org/cosmos/examples" localName="Computer" >
         </s:recordType>
      </s:recordConstraint>
   </s:itemTemplate>
   <s:itemTemplate id="operatingSystems">
      <s:recordConstraint>
         <s:recordType namespace="http://www.eclipse.org/cosmos/examples" localName="OS" >
         </s:recordType>
         <s:propertyValue namespace="http://www.eclipse.org/cosmos/examples" localName="type" >
         <s:equal>Windows</s:equal>
         </s:propertyValue>
      </s:recordConstraint>
   </s:itemTemplate>
   <s:relationshipTemplate id="installedOn">
      <s:sourceTemplate ref="computers" minimum="0" maximum="0" >
      </s:sourceTemplate>
      <s:targetTemplate ref="operatingSystems" minimum="0" maximum="0" >
      </s:targetTemplate>
   </s:relationshipTemplate>
</s:query>

Find computers running Windows

SQL:

select Computer.serialnum, Computer.model, Computer.memory
from Computer, OS
where OS.computer_serialnum=Computer.serialnum and OS.type=WINDOWS

CMDBf Query: 

<s:query xmlns:s="http://cmdbf.org/schema/1-0-0/datamodel">
   <s:itemTemplate id="computers">
      <s:recordConstraint>
         <s:recordType namespace="http://www.eclipse.org/cosmos/examples" localName="Computer" >
         </s:recordType>
      </s:recordConstraint>
   </s:itemTemplate>
   <s:itemTemplate id="operatingSystems" suppressFromResult="true">
      <s:recordConstraint>
         <s:recordType namespace="http://www.eclipse.org/cosmos/examples" localName="OS" >
         </s:recordType>
         <s:propertyValue namespace="http://www.eclipse.org/cosmos/examples" localName="type" >
         <s:equal>Windows</s:equal>
         </s:propertyValue>
      </s:recordConstraint>
   </s:itemTemplate>
   <s:relationshipTemplate id="installedOn">
      <s:sourceTemplate ref="computers" minimum="0" maximum="0" >
      </s:sourceTemplate>
      <s:targetTemplate ref="operatingSystems" minimum="0" maximum="0" >
      </s:targetTemplate>
   </s:relationshipTemplate>
</s:query>

Find serial numbers of computers running windows

SQL:

select Computer.serialnum
from Computer, OS
where OS.computer_serialnum=Computer.serialnum and OS.type=WINDOWS

CMDBf Query: 

<s:query xmlns:s="http://cmdbf.org/schema/1-0-0/datamodel">
   <s:contentSelector>
      <s:selectedRecordType namespace="http://www.eclipse.org/cosmos/examples" 
          localName="Computer">
         <s:selectedProperty namespace="http://www.eclipse.org/cosmos/examples"
             localName="serialnum"/>
      </s:selectedRecordType>
   </s:contentSelector>
   <s:itemTemplate id="computers">
      <s:recordConstraint>
         <s:recordType namespace="http://www.eclipse.org/cosmos/examples" localName="Computer" >
         </s:recordType>
      </s:recordConstraint>
   </s:itemTemplate>
   <s:itemTemplate id="operatingSystems" suppressFromResult="true">
      <s:recordConstraint>
         <s:recordType namespace="http://www.eclipse.org/cosmos/examples" localName="OS" >
         </s:recordType>
         <s:propertyValue namespace="http://www.eclipse.org/cosmos/examples" localName="type" >
         <s:equal>Windows</s:equal>
         </s:propertyValue>
      </s:recordConstraint>
   </s:itemTemplate>
   <s:relationshipTemplate id="installedOn">
      <s:sourceTemplate ref="computers" minimum="0" maximum="0" >
      </s:sourceTemplate>
      <s:targetTemplate ref="operatingSystems" minimum="0" maximum="0" >
      </s:targetTemplate>
   </s:relationshipTemplate>
</s:query>

Find computers running Windows, installed in 2008

SQL (Schema 1):

select Computer.serialnum, Computer.model, Computer.memory
from Computer, OS
where OS.computer_serialnum=Computer.serialnum and OS.type=WINDOWS and OS.installation_date > 2008-01-01

SQL (Schema 2):

select Computer.serialnum, Computer.model, Computer.memory
from Computer, installedOn, OS
where OS.computer_serialnum=Computer.serialnum and OS.type=WINDOWS and installedOn.installation_date > 2008-01-01

CMDBf Query (for Schema 2): 

<s:query xmlns:s="http://cmdbf.org/schema/1-0-0/datamodel">
   <s:itemTemplate id="computers">
      <s:recordConstraint>
         <s:recordType namespace="http://www.eclipse.org/cosmos/examples" localName="Computer" >
         </s:recordType>
      </s:recordConstraint>
   </s:itemTemplate>
   <s:itemTemplate id="operatingSystems" suppressFromResult="true">
      <s:recordConstraint>
         <s:recordType namespace="http://www.eclipse.org/cosmos/examples" localName="OS" >
         </s:recordType>
         <s:propertyValue namespace="http://www.eclipse.org/cosmos/examples" localName="type" >
         <s:equal>Windows</s:equal>
         </s:propertyValue>
      </s:recordConstraint>
   </s:itemTemplate>
   <s:relationshipTemplate id="installedOn">
      <s:sourceTemplate ref="computers" minimum="0" maximum="0" >
      </s:sourceTemplate>
      <s:targetTemplate ref="operatingSystems" minimum="0" maximum="0" >
      </s:targetTemplate>
         <s:recordType namespace="http://www.eclipse.org/cosmos/examples"
            localName="installedOn" >
            <s:propertyValue namespace="http://www.eclipse.org/cosmos/examples" 
               localName="installation_date">
               <greater>2008-01-01</greater>
            </s:propertyValue>
         </s:recordType>
   </s:relationshipTemplate>
</s:query>
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