Github user dongjoon-hyun commented on a diff in the pull request: https://github.com/apache/spark/pull/22868#discussion_r229059209 --- Diff: docs/sql-migration-guide-hive-compatibility.md --- @@ -51,6 +51,22 @@ Spark SQL supports the vast majority of Hive features, such as: * Explain * Partitioned tables including dynamic partition insertion * View + * If column aliases are not specified in view definition queries, both Spark and Hive will + generate alias names, but in different ways. In order for Spark to be able to read views created + by Hive, users should explicitly specify column aliases in view definition queries. As an + example, Spark cannot read `v1` created as below by Hive. + + ``` + CREATE TABLE t1 (c1 INT, c2 STRING); + CREATE VIEW v1 AS SELECT * FROM (SELECT c1 + 1, upper(c2) FROM t1) t2; + ``` + + Instead, you should create `v1` as below with column aliases explicitly specified. + + ``` + CREATE VIEW v1 AS SELECT * FROM (SELECT c1 + 1 AS inc_c1, upper(c2) AS upper_c2 FROM t1) t2; --- End diff -- Also, let's update this one together.
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