flink-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From vasia <...@git.apache.org>
Subject [GitHub] flink pull request: [FLINK-1520]Read edges and vertices from CSV f...
Date Mon, 13 Jul 2015 19:08:56 GMT
Github user vasia commented on the pull request:

    https://github.com/apache/flink/pull/847#issuecomment-121025189
  
    Hi @andralungu,
    
    do you mean support for POJOs as vertex / edge values?
    I guess that's a limitation we can't easily overcome, I agree.
    Still though, a nicely designed `fromCsv()` method would simplify the common case.
    
    As for the examples, I don't like what they currently look like in this PR either. However,
that's not a problem of `fromCsv()`. The if-block can be easily simplified by changing `getDefaultEdgeDataSet`
to `getDefaultGraph`. The else-block looks longer because of the mapper, which, in the current
examples is in the main method.
    
    What I think is quite problematic, is the `types()` methods. Ideally, we would have the
following:
    1. `types(K)` : no vertex value, no edge value
    2. `types(K, VV)`: no edge value
    3. `types(K, EV)`: no vertex value
    4. `types(K, VV, EV)`: both vertex and edge values are present
    However, because of type erasure, we can't have both 2 and 3. The current implementation
(having separate `typesEdges` and `typesVertices`) means that both should always be called,
even if not necessary. Another way would be to give 2 and 3 different names... So far I haven't
been able to come up with a nice solution. Ideas?


---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastructure@apache.org or file a JIRA ticket
with INFRA.
---

Mime
View raw message