Forum Stats

  • 3,854,728 Users
  • 2,264,414 Discussions


enhance ATTRIBUTE CLUSTERING to do "quick & dirty" work

berx Member Posts: 219 Silver Badge
edited Jun 27, 2018 6:43PM in Database Ideas - Ideas

Attribute Clustering requires a sort of the rows before they are stored to disk.

If the rows does not match into PGA, the Sort must be done using TEMP. This can increase the time needed for INSERT dramatically.

To mitigate this effect, I suggest to allow a quick&dirty ATTRIBUTE CLUSTERING: whenever the Sort Area in PGA is totally used, save those rows to disk.

This will lead to sorted sub-chunks on disk, all of the max PGA size.

Even the data will not be that perfect ordered, it can be a reasonable trade-off between un-sorted inserts and slow (dribven by TEMP-Sort) inserts?

This database idea has been accepted and raised as: ENH 27131584 - ENHANCE ATTRIBUTE CLUSTERING TO DO "QUICK & DIRTY" WORK

berxUser259623 -OracleChandrakaanth Ramamurthyvinaykumar2Manish ChaturvediFranck PachotArpit Jain -OracleLothar FlatzJagadekarablessed DBA
12 votes

Under Review - Voting Still Open · Last Updated


  • nbayliss-Oracle
    nbayliss-Oracle Member Posts: 1 Employee

    We are currently considering this idea.

    Can anyone fill me in on how they are using attribute clustering? What kind of use-cases? How many databases? With or without zone maps? Benefits found? Would the change make it more likely that you would use ACs?

    Nigel Bayliss.