From 89673da0beb2b64434d29a94e07fa9c6fb4a93e8 Mon Sep 17 00:00:00 2001
From: Eduard Tudenhoefner <etudenhoefner@gmail.com>
Date: Tue, 5 Dec 2023 10:29:32 -0800
Subject: [PATCH] [SPARK-45807][SQL] Add createOrReplaceView(..) /
 replaceView(..) to ViewCatalog

### What changes were proposed in this pull request?

ViewCatalog API improvements described in [SPIP](https://docs.google.com/document/d/1XOxFtloiMuW24iqJ-zJnDzHl2KMxipTjJoxleJFz66A/edit?usp=sharing) that didn't make it into the codebase as part of #37556

### Why are the changes needed?

Required for DataSourceV2 view support.

### Does this PR introduce _any_ user-facing change?

No
### How was this patch tested?

N/A

### Was this patch authored or co-authored using generative AI tooling?

N/A

Closes #43677 from nastra/SPARK-45807.

Authored-by: Eduard Tudenhoefner <etudenhoefner@gmail.com>
Signed-off-by: Holden Karau <holden@pigscanfly.ca>
---
 .../sql/connector/catalog/ViewCatalog.java    | 86 +++++++++++++++++++
 1 file changed, 86 insertions(+)

diff --git a/sql/catalyst/src/main/java/org/apache/spark/sql/connector/catalog/ViewCatalog.java b/sql/catalyst/src/main/java/org/apache/spark/sql/connector/catalog/ViewCatalog.java
index eb67b9904869d..eef348928b2ca 100644
--- a/sql/catalyst/src/main/java/org/apache/spark/sql/connector/catalog/ViewCatalog.java
+++ b/sql/catalyst/src/main/java/org/apache/spark/sql/connector/catalog/ViewCatalog.java
@@ -140,6 +140,92 @@ View createView(
       String[] columnComments,
       Map<String, String> properties) throws ViewAlreadyExistsException, NoSuchNamespaceException;
 
+  /**
+   * Replace a view in the catalog.
+   * <p>
+   * The default implementation has a race condition.
+   * Catalogs are encouraged to implement this operation atomically.
+   *
+   * @param ident a view identifier
+   * @param sql the SQL text that defines the view
+   * @param currentCatalog the current catalog
+   * @param currentNamespace the current namespace
+   * @param schema the view query output schema
+   * @param queryColumnNames the query column names
+   * @param columnAliases the column aliases
+   * @param columnComments the column comments
+   * @param properties the view properties
+   * @throws NoSuchViewException If the view doesn't exist or is a table
+   * @throws NoSuchNamespaceException If the identifier namespace does not exist (optional)
+   */
+  default void replaceView(
+          Identifier ident,
+          String sql,
+          String currentCatalog,
+          String[] currentNamespace,
+          StructType schema,
+          String[] queryColumnNames,
+          String[] columnAliases,
+          String[] columnComments,
+          Map<String, String> properties) throws NoSuchViewException, NoSuchNamespaceException {
+    if (viewExists(ident)) {
+      dropView(ident);
+      try {
+        createView(ident, sql, currentCatalog, currentNamespace, schema,
+                queryColumnNames, columnAliases, columnComments, properties);
+      }
+      catch (ViewAlreadyExistsException e) {
+        throw new RuntimeException("Race condition when dropping and creating view", e);
+      }
+    } else {
+      throw new NoSuchViewException(ident);
+    }
+  }
+
+  /**
+   * Create or replace a view in the catalog.
+   * <p>
+   * The default implementation has race conditions.
+   * Catalogs are encouraged to implement this operation atomically.
+   *
+   * @param ident a view identifier
+   * @param sql the SQL text that defines the view
+   * @param currentCatalog the current catalog
+   * @param currentNamespace the current namespace
+   * @param schema the view query output schema
+   * @param queryColumnNames the query column names
+   * @param columnAliases the column aliases
+   * @param columnComments the column comments
+   * @param properties the view properties
+   * @throws NoSuchNamespaceException If the identifier namespace does not exist (optional)
+   */
+  default void createOrReplaceView(
+          Identifier ident,
+          String sql,
+          String currentCatalog,
+          String[] currentNamespace,
+          StructType schema,
+          String[] queryColumnNames,
+          String[] columnAliases,
+          String[] columnComments,
+          Map<String, String> properties) throws NoSuchNamespaceException {
+    if (viewExists(ident)) {
+      try {
+        replaceView(ident, sql, currentCatalog, currentNamespace, schema,
+                queryColumnNames, columnAliases, columnComments, properties);
+      } catch (NoSuchViewException e) {
+        throw new RuntimeException("Race condition when checking and replacing view", e);
+      }
+    } else {
+      try {
+        createView(ident, sql, currentCatalog, currentNamespace, schema,
+                queryColumnNames, columnAliases, columnComments, properties);
+      } catch (ViewAlreadyExistsException e) {
+        throw new RuntimeException("Race condition when checking and creating view", e);
+      }
+    }
+  }
+
   /**
    * Apply {@link ViewChange changes} to a view in the catalog.
    * <p>