> On Feb. 15, 2017, 11:51 p.m., Madhan Neethiraj wrote: > > intg/src/main/java/org/apache/atlas/model/instance/AtlasObjectId.java, line > > 53 > > <https://reviews.apache.org/r/56105/diff/1/?file=1619639#file1619639line53> > > > > AtlasObjectId should point to an unique object; hence the use of > > 'uniqueAttributes' here. If a non-unique attribute is allowed, it can > > potentially match muliple objects - making AtlasObjectId ambigious. > > David Radley wrote: > Policing attributes in graphs to be unique is problematic; how do you > police uniqueness without big graph scans. If we label attributes as unique > but do not police it - this is misleading as the attriubutes may not be > unique in reality. > Too many unique attributes would lead to a proliferation of indexes and > associated performance implications. RDBs have slick mechanisms for dealing > with primary keys and foreign keys and the like - they can readily do this as > they are set based. This is why I think we should not be encouraging the use > of unique attributes. I think being able to specify any attribute would help; > for example a name is useful but not unique. > > Madhan Neethiraj wrote: > Some attributes, like employee_id/dept_id can be used to identify a > specific entity instance. Contrast this with other attributes, like > comment/description/createTime, which can't be used identify a specific > instance. > > Wouldn't it be useful to distinguish attributes based on above criteria?
If Atlas could trust the source system to police the field to be unique (so Atlas does not need to police it), for example if this was an RDB foreign key; this would be very useful. For other cases when there is no unique attribute, then adding a non-unique attribute would also be useful For glossary terms and categories (an area,I am looking into in ATLAS-1410), they have no unique attributes apart from the guid, they do have name attribute as a human readable way of identifying an object instance, but is probably not unique. I was hoping that this fix would allow me to include the name field in the relationship - this turned out to be very useful for debugging in my prototyping. - David ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/56105/#review165780 ----------------------------------------------------------- On Jan. 31, 2017, 1:08 a.m., Madhan Neethiraj wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://reviews.apache.org/r/56105/ > ----------------------------------------------------------- > > (Updated Jan. 31, 2017, 1:08 a.m.) > > > Review request for atlas. > > > Bugs: ATLAS-1506 > https://issues.apache.org/jira/browse/ATLAS-1506 > > > Repository: atlas > > > Description > ------- > > Attribute uniqueAttribues is now added to AtlasObjectId. > > > Diffs > ----- > > intg/src/main/java/org/apache/atlas/model/instance/AtlasObjectId.java > 4896e9d > intg/src/main/java/org/apache/atlas/type/AtlasBuiltInTypes.java a25f3f6 > intg/src/test/java/org/apache/atlas/type/TestAtlasObjectIdType.java 7d55233 > > Diff: https://reviews.apache.org/r/56105/diff/ > > > Testing > ------- > > - updated unit tests to cover the changes to AtlasObjectId > > > Thanks, > > Madhan Neethiraj > >
