LTXHWM

onconfig.std value

None (not present in onconfig.std)

if not present

80 (if DYNAMIC_LOGS is set to 1 or 2)
50 (if DYNAMIC_LOGS is set to 0)

units

Percent

range of values

1 through 100

takes effect

When the database server is shut down and restarted

refer to

The following material:

• DYNAMIC_LOGS
• LTXEHWM
• Setting high-watermarks for rolling back long transactions, in the chapter on managing logical logs in the IBM Informix Administrator's Guide

LTXHWM specifies the long-transaction high-watermark. The long-transaction high-watermark is the percentage of available log space that, when filled, triggers the database server to check for a long transaction. When the logical-log space reaches the LTXHWM threshold, the database server starts rolling back the transaction. If you decrease the LTXHWM value, increase the size or number of log files to make rollbacks less likely.

If DYNAMIC_LOGS is set to 1 or 2, the database server adds as many logs are needed to complete the rollback.

If you do not want too many logical logs to be added, LTXHWM should be set to a smaller value (around 60). If dynamic logging is turned off (DYNAMIC_LOGS = 0), LTXHWM should be set lower (around 50) to avoid running out of logical space.

If you set LTXHWM to 100, the database server issues a warning message:

LTXHWM is set to 100%. This long transaction high water mark will never be reached.
Transactions will not be aborted automatically by the server, regardless of their length.

If the transaction hangs, follow the instructions for recovering from a long transaction hang, in the chapter on managing logical-log files in the IBM Informix Administrator's Guide.