accumulo-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Josh Elser <>
Subject Re: "NOT" operator in visibility string
Date Wed, 05 Mar 2014 21:30:37 GMT
Hi Joe,

I believe the biggest reason that a NOT operator is not included in the
syntax is for simplicity.

It's humorous how often even experienced users can find themselves tracking
down "why can't I see my data" at the application level when the problem
was just incorrect markings or authorizations.

Second, the functionality is already present by the lack of providing the
label which you want to negate. Categorizing data into static labels tends
to be more manageable over using many roles. While enumerating the inverse
of a negation is possible, it is valid that the marking may be much larger
on disk than a representation using a negation.

Another important tidbit (not sure if you realized yet), but it will be
tricky to make sure that the flatten method in ColumnVisibility still works
correctly. This makes sure that CVs are "normalized" to equivalent forms.
Adding parens can likely make it easier, but that's something else to keep
in mind.

That being said, you should feel free to open an issue when you have a
patch ready and we can continue the conversation about including a new
operator on the mailing lists.

On Mar 5, 2014 3:49 PM, "joeferner" <> wrote:

> I'm looking at implementing the "NOT" operator in visibility strings. I
> actually have it working just need to write some unit tests for it. I was
> wondering if there was any reason why it don't exist now? It looks to be
> explicitly called out in the docs "dog|!cat".
> The new HBase also looks to support the "NOT" operator:
> --
> View this message in context:
> Sent from the Users mailing list archive at

View raw message