Forum Stats

  • 3,874,720 Users
  • 2,266,768 Discussions
  • 7,911,958 Comments

Discussions

Hint to enforce "temp segment merge"

Lothar Flatz
Lothar Flatz Member Posts: 687 Silver Badge
edited Dec 3, 2018 7:56AM in Database Ideas - Ideas

When doing a direct path load the database has two different basic strategies, temp segment merge and brokered load.

https://blogs.oracle.com/optimizer/space-management-and-oracle-direct-path-load

There is a hint to enable brokered load (HWM_BROKERED ) but there is no hint to switch it off.

There is no hint to enable temp segment merge.

For some highly parallel inserts temp segment merge is the best strategy. If the inserts grows the segment quickly, brokered load can result in "enq: HV contention" waits.

The only way brokered load can be switched off is the hidden parameter "_INSERT_ENABLE_HWM_BROKERED" on system level.

This option is almost useless, because HWB is the better overall stategey. Only for some selected statements TSM is perferrable.

Lothar Flatz3829078Randolf GeistSven W.ctriebKazuhiroberxBPeaslandDBA
8 votes

Active · Last Updated