High water mark is the maximum amount of database blocks used so far by a segment. This mark cannot be reset by delete operations.
When there is a lob column in any table, heavy insert can cause enq high water mark contention due to increase in volume of inserts.
TRUNCATE will reset HWM
The blocks above the HWM level is free blocks, they are ready to use. exception Above the HWM when using the APPEND hint in the INSERT statement (or using DIRECT=Y in sql*loader)
We have to set the event available as below to higher value to reduce enq High water mark contention. ALTER SYSTEM SET EVENT=”44951 TRACE NAME CONTEXT FOREVER, LEVEL <1 - 1024>” scope=spfile;
When there is a lob column in any table, heavy insert can cause enq high water mark contention due to increase in volume of inserts.
TRUNCATE will reset HWM
The blocks above the HWM level is free blocks, they are ready to use. exception Above the HWM when using the APPEND hint in the INSERT statement (or using DIRECT=Y in sql*loader)
We have to set the event available as below to higher value to reduce enq High water mark contention. ALTER SYSTEM SET EVENT=”44951 TRACE NAME CONTEXT FOREVER, LEVEL <1 - 1024>” scope=spfile;
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