GitHub user jiangxb1987 opened a pull request:
https://github.com/apache/spark/pull/17152
[SPARK-18389][SQL] Disallow cyclic view reference
## What changes were proposed in this pull request?
Disallow cyclic view references, a cyclic view reference may be created by
the following queries:
```
CREATE VIEW testView AS SELECT id FROM tbl
CREATE VIEW testView2 AS SELECT id FROM testView
ALTER VIEW testView AS SELECT * FROM testView2
```
In the above example, a reference cycle (testView -> testView2 -> testView)
exsits.
We disallow cyclic view references by checking that in ALTER VIEW command,
when the `analyzedPlan` contains the same `View` node with the altered view, we
should prevent the behavior and throw an AnalysisException.
## How was this patch tested?
Test by `SQLViewSuite.test("correctly handle a cyclic view reference")`.
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/jiangxb1987/spark cyclic-view
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/spark/pull/17152.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #17152
----
commit 1bd02603fa24e6790994105cd47c8b55a4c1de40
Author: jiangxingbo <[email protected]>
Date: 2017-03-03T15:30:59Z
detect cyclic view references.
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