[jira] Commented: (DIRRMS-22) Need mechanism to find index holes in the bit vector

[ji...@apache.org]

The following comment has been added to this issue:

     Author: Alex Karasulu
    Created: Mon, 19 Apr 2004 12:35 PM
       Body:
Holes need to be filled within bit permissions database.

rowIds  values
     |  |
     |  |
     V  V     Hole at index 2
    •-•-•
    |1|*|---> perm at index 0
    |2|*|---> perm at index 1
    |4|*|---> perm at index 3
    |5|*|---> perm at index 4
    | | |
    | | |
    •-•-•

rowIds  values
     |  |
     |  |
     V  V     Hole filled!
    •-•-•
    |1|*|---> perm at index 0
    |2|*|---> perm at index 1
    |4|*|---> perm at index 3
    |5|*|---> perm at index 4
    |6|*|---> perm at index 2
    | | |
    •-•-•

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View this comment:
  http://issues.apache.org/jira/browse/DIRRMS-22?page=comments#action_35152

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View the issue:
  http://issues.apache.org/jira/browse/DIRRMS-22

Here is an overview of the issue:
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        Key: DIRRMS-22
    Summary: Need mechanism to find index holes in the bit vector
       Type: Task

     Status: Open
   Priority: Major

    Project: Directory RMS
 Components: 
             Berkeley JE

   Assignee: Alex Karasulu
   Reporter: Alex Karasulu

    Created: Mon, 19 Apr 2004 9:46 AM
    Updated: Mon, 19 Apr 2004 12:35 PM

Description:
Right now it's not all that simple to rapidly find the next available bit index to occupy.  One would think the secondary indices would help and they do but since all permissions from all applications are involved the problem is not as simple as it seems.  At first glance it might appear as though a join would work but we still need to find the smallest available index and so order creeps into the picture taking the option of a join out.  

Keep in mind this operation is for writes and it need not be that fast since we're optimized for reads.  However it still needs to be efficient regardless and fairly straight forward.


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