DEF_TABLE_LOCKMODE configuration parameter

Use the DEF_TABLE_LOCKMODE configuration parameter to specify the lock mode at the page or row level for new tables.

onconfig.std value
PAGE
values
PAGE = sets lock mode to page for new tables
ROW = sets lock mode to row for new tables
takes effect
After you edit your onconfig file and restart the database server.
When you reset the value dynamically in your onconfig file by running the onmode -wf command.
When you reset the value in memory by running the onmode -wm command.
precedence rules
You can supersede all other lock mode settings for a specific table by including the LOCK MODE clause in the CREATE TABLE or ALTER TABLE statement.
The IFX_DEF_TABLE_LOCKMODE environment variable set on the client takes precedence over the variable on the server and the DEF_TABLE_LOCKMODE configuration parameter.
The IFX_DEF_TABLE_LOCKMODE environment variable set on the server takes precedence over the DEF_TABLE_LOCKMODE configuration parameter.

Usage

If the DEF_TABLE_LOCKMODE configuration parameter is set to ROW, it sets the lock mode to row for every newly created table for all sessions that are connected to logging or nonlogging databases. This parameter has no effect on the lock mode for existing tables.

If the DEF_TABLE_LOCKMODE configuration parameter is set to PAGE, the USELASTCOMMITTED configuration parameter and COMMITTED READ LAST COMMITTED option of the SET ISOLATION statement cannot enable access to the most recently committed data in tables on which uncommitted transactions hold exclusive locks, unless the tables were explicitly created or altered to have ROW as their locking granularity.


Copyright© 2019 HCL Technologies Limited