Development Specifications

If the connection pool mechanism is used during application development, comply with the following specifications:

• If GUC parameters are set in the connection, run SET SESSION AUTHORIZATION DEFAULT;RESET ALL; to clear the connection status before you return the connection to the connection pool.
• If a temporary table is used, delete the temporary table before you return the connection to the connection pool.

If you do not do so, the connection state in the connection pool will remain, which affects subsequent operations using the connection pool.

Table 1 describes the compatibility of application development drivers.

Table 1 Compatibility description

Driver	Compatibility Description
JDBC, Go, ODBC, libpq, Psycopg, and ecpg	The new drivers are forward compatible with the database. To use the new features added to the driver and database, you must upgrade the database.

• In principle, you need to set the compatibility parameter after the database creation, instead of switching the parameters when using the database.
• The JDBC driver must be upgraded to that maps to GaussDB Kernel 503.1.0 or later if the following features are used:
  • The s2 compatibility parameter is enabled and the validity check of sessiontimezone is set.

If the driver is used in a multi-thread environment:

The JDBC driver is not thread-safe and does not guarantee that the connection methods are synchronized. The caller synchronizes the calls to the driver.