Getting Startedwith pureQuery

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Getting Started with pureQuery
ON for the property pdq.captureMode, and the value DYNAMIC for the property
pdq.executionMode.
# This is a comment.
pdq.pureQueryXml=C:\\path\\captureFile.pdqxml
pdq.captureMode=ON
pdq.executionMode=DYNAMIC
Listing 6.1 - An example of specifying pureQuery properties in a properties file
As will be described later, you must specify pureQuery properties to use Client Optimizer
functionality. The pureQuery properties must be specified when your application creates
java.sql.Connection objects. If they are not, the application uses standard JDBC
functionality.
Refer to the IBM Optim pureQuery Runtime documentation for a complete list of the
pureQuery properties, along with information about their use.
6.5 Capturing SQL statements
The first step in using the Client Optimizer is to capture all of the SQL statements in the
application into a pureQueryXml file. You tell pureQuery to capture SQL statements by
setting certain properties in the pureQuery properties. pureQuery captures each SQL
statement only once. pureQuery considers two SQL statements to be the same if the text
of the SQL is identical (including capitalization and white space) and they have identical
execution characteristics. Additionally, pureQuery only captures SQL statements that a
JDBC application executes successfully. Therefore, if an application prepares a statement
without executing it, or if an application attempts to execute an SQL statement but the
execution fails, pureQuery will not capture that statement.
If you want pureQuery to capture all of the SQL statements that your application executes,
clearly your application needs to successfully execute all of the statements while you are
performing the capture. Usually, the easiest way to do this is to direct pureQuery to
capture during the execution of the tests of your application. You can capture SQL
statements incrementally; that is, if you capture SQL statements into a pureQueryXml file,
you can later capture again, specifying the same pureQueryXml file. If you do this,
pureQuery simply adds the newly captured SQL statements to your existing pureQueryXml
file. You can even capture during static execution, if you set the pureQuery properties
correctly.
If you capture SQL statements to create a pureQueryXml file, and then you modify your
application, IBM recommends that you delete your pureQueryXml file and capture again to
replace it. Otherwise, your pureQueryXml file can become bloated with information about
SQL statements that your application no-longer executes, as well as inaccurate information
about which parts of your application execute certain SQL statements.