Getting Startedwith pureQuery

Chapter 6 – The Client Optimizer: pureQuery for Existing Applications 113
There are several ways to specify pureQuery properties. The most common ways are in a
properties file and as the value of the IBM Data Server Driver for JDBC and SQLJ property
pdqProperties. For each property, pureQuery looks for that property in several
locations, in a particular order. pureQuery uses the first value that it finds. If pureQuery
does not find the property, pureQuery uses the default value of that property. The following
lists describe the standard approaches for specifying pureQuery properties.
Connection through a DataSource object: If the application creates a connection to the
database by using a javax.sql.DataSource object, pureQuery searches for pureQuery
properties in these locations, in the order in which they are listed.
1. A file named pdq.dataSourceName.properties in your application classpath,
where dataSourceName represents the name of the DataSource object
2. A file named pdq.appwide.properties in your application classpath
3. The value of the property pdqProperties in the DataSource object. The
implementations of javax.sql.DataSource that the IBM Data Server Driver for
JDBC and SQLJ provides, as well as those that pureQuery provides, have a
method setPdqProperties(String) that you can use for setting this. When
you specify pureQuery properties in this way, you do not need to include the
“pdq.” in the property names.
4. A file named pdq.properties in the classpath that indicates the location of the
JDBC driver.
Connection through the DriverManager class: If the application creates a connection
to the database by using the java.sql.DriverManager class, pureQuery searches
pureQuery properties in these locations, in the order in which they are listed.
1. The value of the property pdqProperties in the URL. When you specify
pureQuery properties in this way, you do not need to include the “pdq.” in the
property names.
2. A java.util.Properties object that is passed as a parameter to a
java.sql.DriverManager.getConnection method. When you specify
pureQuery properties in this way, you do not need to include the “pdq.” in the
property names.
3. A file named pdq.properties in the classpath.
If you use a properties file to specify pureQuery properties, each line of the file should
contain the name of a property, then an equal sign (=), and finally the value for that
property. If you want a line in a properties file to be a comment that pureQuery ignores,
make # the first character of the line. The backslash character (\) is an escape character,
so if you want to use a backslash in the value of a property, you need to specify two
backslashes (\\). Listing 6.1 provides an example of a properties file that specifies the
value C:\path\captureFile.pdqxml for the property pdq.pureQueryXml, the value