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From Geoffry Roberts <threadedb...@gmail.com>
Subject Re: Embedded Mutations: Is this kind of thing done?
Date Fri, 25 Apr 2014 14:53:35 GMT
Ok Josh, you have me worried.

I am storing the object's name in the colfam: e.g. "patientId", the
object's data type goes in the colq: e.g "org.hl7.v3.II", then the value in
the colval.  I think the largest graph I'm likely to have is < 5k and you
say I soul have memory problems.  This is good topic.  How then can I
estimate?


On Fri, Apr 25, 2014 at 10:17 AM, Josh Elser <josh.elser@gmail.com> wrote:

> Not necessarily. If you are storing just the type in the colq and have one
> value and type per document/row, you won't have a problem. If you have more
> than one value in a type per document/row, the last one you inserted will
> be what sticks (which is likely undesirable).
>
> Of course, this is also assuming there isn't some other uniquely
> identifying attribute in the colfam.
>
>
> On 4/25/14, 9:55 AM, Geoffry Roberts wrote:
>
>> Thanks for the comments.
>>
>> I'm using the qualifier to tell me the type of the value.  Sounds like
>> I'm misusing it.
>>
>> My EMF documents are running  no more than 5k so I gather a row will fit
>> into memory well enough.
>>
>>
>> On Fri, Apr 25, 2014 at 9:29 AM, Mike Drob <madrob@cloudera.com
>> <mailto:madrob@cloudera.com>> wrote:
>>
>>     Large rows are only an issue if you are going to try to put the
>>     entire row in memory at once. As long as you have small enough
>>     entries in the row, and can treat them individually, you should be
>> fine.
>>
>>     The qualifier is anything that you want to use to determine
>>     uniqueness across keys. So yes, this sounds fine, although possibly
>>     not fine grain enough.
>>
>>     Mike
>>
>>
>>     On Fri, Apr 25, 2014 at 9:11 AM, Geoffry Roberts
>>     <threadedblue@gmail.com <mailto:threadedblue@gmail.com>> wrote:
>>
>>         Interesting, multiple mutations that is.  Are we talking
>>         multiples on the same row id?
>>
>>         Upon reflection, I realized the embedded thing is nothing
>>         special.  I think I'll keep adding columns to a single mutation.
>>           This will make for a wide row, but I'm not seeing that as a
>>         problem.  I am I being naive?
>>
>>         Another question if I may.  As I walk my graph, I must keep
>>         track of the type of the value being persisted.  I am using the
>>         qualifier for this, putting in it a URI that indicates the type.
>>           Is this a proper use for the qualifier?
>>
>>         Thanks for the discussion
>>
>>
>>         On Thu, Apr 24, 2014 at 11:23 PM, William Slacum
>>         <wilhelm.von.cloud@accumulo.net
>>         <mailto:wilhelm.von.cloud@accumulo.net>> wrote:
>>
>>             Depending on your table schema, you'll probably want to
>>             translate an object graph into multiple mutations.
>>
>>
>>             On Thu, Apr 24, 2014 at 8:40 PM, David Medinets
>>             <david.medinets@gmail.com <mailto:david.medinets@gmail.com>>
>>
>>             wrote:
>>
>>                 If the sub-document changes, you'll need to search the
>>                 values of every Accumulo entry?
>>
>>
>>                 On Thu, Apr 24, 2014 at 5:31 PM, Geoffry Roberts
>>                 <threadedblue@gmail.com <mailto:threadedblue@gmail.com>>
>>
>>                 wrote:
>>
>>                     The use case is, I am walking a complex object graph
>>                     and persisting what I find there.  Said object graph
>>                     in my case is always EMF (eclipse modeling
>>                     framework) compliant.  An EMF graph can have in if
>>                     references to--brace yourself--a non-cross document
>>                     containment reference.  When using Mongo, these were
>>                     persisted as a DBObject embedded into a containing
>>                     DBObject.  I'm trying to decide whether I want to
>>                     follow suit.
>>
>>                     Any thoughts?
>>
>>
>>                     On Thu, Apr 24, 2014 at 4:03 PM, Sean Busbey
>>                     <busbey@cloudera.com <mailto:busbey@cloudera.com>>
>>
>>                     wrote:
>>
>>                         Can you describe the use case more? Do you know
>>                         what the purpose for the embedded changes are?
>>
>>
>>                         On Thu, Apr 24, 2014 at 2:59 PM, Geoffry Roberts
>>                         <threadedblue@gmail.com
>>                         <mailto:threadedblue@gmail.com>> wrote:
>>
>>                             All,
>>
>>                             I am in the throws of converting
>>                             some(else's) code from MongoDB to Accumulo.
>>                               I am seeing a situation where one DBObject
>>                             if being embedded into another DBObject.  I
>>                             see that Mutation supports a method called
>>                             getRow()  that returns a byte array.  I
>>                             gather I can use this to achieve a similar
>>                             result if I were so inclined.
>>
>>                             Am I so inclined?  i.e. Is this the way we
>>                             do things in Accumulo?
>>
>>                             DBObject, roughly speaking, is Mongo's
>>                             counterpart to Mutation.
>>
>>                             Thanks mucho
>>
>>                             --
>>                             There are ways and there are ways,
>>
>>                             Geoffry Roberts
>>
>>
>>
>>
>>                         --
>>                         Sean
>>
>>
>>
>>
>>                     --
>>                     There are ways and there are ways,
>>
>>                     Geoffry Roberts
>>
>>
>>
>>
>>
>>
>>         --
>>         There are ways and there are ways,
>>
>>         Geoffry Roberts
>>
>>
>>
>>
>>
>> --
>> There are ways and there are ways,
>>
>> Geoffry Roberts
>>
>


-- 
There are ways and there are ways,

Geoffry Roberts

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