Feature issue#12

[onderkalaci]

Shards backed by foreign tables marked correctly in the metadata.

Tested with:

1. Postgres 9.4
   • foreign table - SELECT/INSERT
   • normal table (RELKIND_RELATION) - SELECT/INSERT
2. Citus 3.0.1
   • foreign table - SELECT problematic - sent mail to @jasonmp85. But I don't think it is related to this fix, because when I test with undoing the fix, we still have the problem.
   • foreign table - INSERT OK
   • normal table (RELKIND_RELATION) - select/insert

closes #12

Review tasks:

• [x] Make call to get_rel_relkind during declaration of relationKind
• [x] Move declaration of shardStorageType to immediately after relationKind declaration
• [x] Add tests for this functionality (distribute a foreign table and verify the 'f' using a SELECT)

[jasonmp85]

I made two comments in the source that need to be addressed. Also: run the tests (make installcheck) and add a new one to verify that 'f' is inserted where we expect it.

[jasonmp85]

I've added a checklist to the PR description: after you address all items, we can :shipit:

[jasonmp85]

If you need guidance on how to add a test, check out 1247452e3d89497d1d54b59b7d6735d71d6652f8, in which I added a test for the bug when you try to distribute an index.

[coveralls]

Coverage increased (+0.01%) when pulling b659a6559d7695c93eca0c6b06fcff6b94377819 on feature-issue#12 into 46bcf2c0b1a5250a286e5dd6b0e9fa42e275725f on develop.

[onderkalaci]

@jasonmp85 Since it is the first time I wrote regression tests, it would be nice if you can check it in detail. I had to change expected/modifications.out.tmpl", is that required or useless? Is there a way not to do that?

[jasonmp85]

If you look into the Makefile, you'll see that the tmpl files are used to generate the sql and out files for certain tests. This is because certain tests' output will contain the port number of the PostgreSQL instance being used and since make installcheck just checks against the current installation, we have no way of predicting what that will be. So if a tmpl file exists, it should be what you modify; otherwise, just modify the sql and out files as necessary.

[jasonmp85]

This looks good! Merging.