Christopher Tubbs created ACCUMULO-918:
------------------------------------------

             Summary: Support secondary ColumnVisibility filtering
                 Key: ACCUMULO-918
                 URL: https://issues.apache.org/jira/browse/ACCUMULO-918
             Project: Accumulo
          Issue Type: Improvement
          Components: tserver
            Reporter: Christopher Tubbs
            Assignee: Christopher Tubbs
             Fix For: 1.5.0


To some degree, users have the ability to choose what to see during a scan, by 
providing a subset of their own authorizations at scan time. However, even this 
only gives the user the ability to filter using a *disjunction* of all elements 
in that subset (in other words, if it matches *any* of their authorizations). 
Users are not able to request data that matches a *conjunction* of the elements 
in their set of authorizations (or the subset requested at scan time).

Example:
User has auths: {color:blue}a,b{color}
User can see entries labeled with any of the following:
{color:blue}
{noformat}
a
a|b
{noformat}
{color}

If the user desired to only view entries that matched the disjunction, 
{color:blue}a|b{color}, and not {color}a{color} only, then this is not 
currently possible. The reason this isn't possible is because the design of the 
VisibilityFilter is to prevent users from getting access to data they are not 
allowed to see. It does nothing to constrain the data to only what they *want* 
to see.

This can be done on the client side, but it can also be achieved with a 
secondary filter applied later in the iterator stack, so that the undesirable 
data doesn't get sent back over the network in the first place.

Consider the same situation, but the user wants to match entries that are 
visible by {color:blue}a{color} *AND* visible by {color:blue}b{color}.
After the system iterator is applied, the user can see:
{color:blue}
{noformat}
a
a|b
{noformat}
{color}
After the second iterator is applied, with the authorizations 
{color:blue}b{color} specified, the user can see only:
{color:blue}
{noformat}
a|b
{noformat}
{color}

As a system iterator, the current VisibilityFilter cannot be used by users, as 
it doesn't properly get initialized with init(), and is constructed using an 
alternate constructor on the tserver. So, the VisibilityFilter needs to be 
changed to support being used by users in the iterator stack, or another filter 
needs to provide similar functionality for users.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

Reply via email to