JDBC Type 4 Driver Performance Tuning Guide for Version 1.0

HP NonStop JDBC Type 4 Driver
Performance Tuning Guide for Version 1.0
Page 3 Hewlett-Packard Company — 529619-001 November 29, 2004
run time. Set these values appropriately with your data source properties.
Note: theses properties are not reset when a connection is pooled.
• Use prepared statements (PreparedStatement class), and parameterize its
arguments.
• Avoid retrieving unnecessary columns: don't use "SELECT *".
• Turn off autocommit when possible (the default is on). All transaction levels
might operate faster with autocommit turned off, although using this setting
requires you to code commits. Leave autocommit on for single statements.
• Avoid repeatedly calling expensive database query functions such as:
getBestRowIdentifier; getColumns, getCrossReference, get ExportedKeys,
getImportedKeys, getPrimaryKeys, getTables, and getVersionColumns. If
possible, call these functions once, and cache the returned data.
• Use the type-correct get() method, rather than getObject().
• Always close Statement and ResultSet objects as soon as possible.
• Use “BROWSE” (READ UNCOMMITTED) access on SQL statements when
possible.
4 MXCS Tuning Tips
• Use a non-default server data source when making a connection, and
configure the data source to optimize performance for your environment. See
the “serverDataSource” property in the NonStop JDBC Type 4 Driver
Programmer’s Reference manual, and “server data source” in the SQL/MX
Connectivity Service Manual.
5 Database Tuning Tip
• See the SQL/MX Query Guide.
• Safeguard supports multiple alias and password pairs for a single Guardian
user name. Using these aliases or password pairs can improve performance
because object caching reuses the underlying user name. You can set up an
anonymous log-in capability by adding a user name such as guest with no
password; then map this user name to a user group that has limited access to
the SQL objects.