 | Enable an existing application for pureQuery using client
optimization
A key benefit of pureQuery is the ability for database applications to
take advantage of static SQL when they may not have been able to
before. As mentioned before, static SQL (as defined by DB2) is the
ability to precompile an application's SQL before the application is
executed for the first time. Having this information can provide
insights that may improve performance, problem determination, and
security.
Support for static SQL in new application development has been around
for a long time for traditional programming languages (for example,
COBOL or C) and more recently for Java applications (for example,
through Java's SQLJ language extension and the Java pureQuery API).
Existing ODBC- and CLI-based applications that were implemented
without the programming languages static SQL support can leverage
static SQL through DB2's CLI/ODBC Static Profiling feature. With the
introduction of the pureQuery client optimization feature, existing
.NET applications can now also reap the benefits of static SQL.
The pureQuery client optimization feature was designed with those
existing applications in mind, for which a re-implementation of the
data access layer (to take advantage of static SQL) is not a viable
option. The process of enabling an existing application for pureQuery
(or in other words, static SQL) is divided into four phases, which are
depicted in Figure 3.
Figure 3. pureQuery client
optimization process overview
-
Capture: You configure the IBM Data Server Provider for
.Net, which is used by .NET applications to access DB2 data
servers, to capture the application's successfully executed SQL
while that application is running. The captured information is
stored in a text file, which is processed in a subsequent phase by
a DB2 utility and consumed by the IBM Data Server Provider for
.Net.
-
Configure: The captured SQL and its associated metadata is
enriched with information that enables a DB2 utility to create one
or more database packages, which enable the IBM Data Server
Provider for .Net to execute SQL statically.
-
Bind: Use the
db2cap utility to
process the configured metadata file and create database packages
that correlate to the captured SQL.
-
Execute: Configure the IBM Data Server Provider for .Net to
statically process SQL you had previously captured, configured,
and bound.
This process is an iterative process that is typically performed in a
test environment. Once the target application has been validated, you
can move it and its associated pureQuery-related artifacts (the
configured capture file and the database packages) to the production
environment.
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