MX 2.x)

Starting, Configuring, and Managing MXCS

HP NonStop SQL/MX Connectivity Service Manual—524944-008

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Benefits of MFC

JDBC applications that use the java.sql.PreparedStatement object and ODBC

applications that use complex queries through the path SQLPrepare() ->SQLExecute()

-> SQLFetch() calls result in lower processor utilization, lower memory consumption,

and better response time.

A query that uses the java.sql.Statement object from JDBC and the

execdirect () API from ODBC will not benefit from the MFC feature. For

information on specific benefits from MFC, see the Module File Cache For NonStop

ODBC/MX and JDBC/T4 Drivers White Paper.

Limitations of MFC

•

It does not handle session-specific SQL/MX Control Query Defaults (CQD) and

SQL/MX Control Query Shape (CQS).

•

For light weight queries, MFC performs only marginally better than SQL/MX

compile.

•

MFC is not supported for rowset operations.

Troubleshooting MFC

The troubleshooting of MFC includes:

•

.lock Files

•

.mdf Files

•

.lst Files

•

.sql Files

•

Disk Activity

•

Enable Fileset and OSS Caching

•

Known Issues

.lock Files

The *.lock files are generated for every query that pass through the MFC module file

creation process. These files are also used for synchronizing, so that different

connections do not re-create the same module file. The *.lock files are deleted from the

specified compiled_module_location directory after the binary module is

successfully created.

The *.lock files are not deleted for the queries that cannot create module files. For

example, ODBC application queries using scalar functions, such as SUM or AVG or

ABS cannot create module files.