Add support for SHOW CREATE SCHEMA

Author: agrawalreetika

Diff for: presto-docs/src/main/sphinx/sql.rst

@@ -47,6 +47,7 @@ This chapter describes the SQL syntax used in Presto.
     sql/show-catalogs
     sql/show-columns
     sql/show-create-function
+    sql/show-create-schema
     sql/show-create-table
     sql/show-create-view
     sql/show-functions

Diff for: presto-docs/src/main/sphinx/sql/show-create-schema.rst

@@ -0,0 +1,37 @@
+=================
+SHOW CREATE SCHEMA
+=================
+
+Synopsis
+--------
+
+.. code-block:: none
+
+    SHOW CREATE SCHEMA schema_name
+
+Description
+-----------
+
+Show the SQL statement that creates the specified schema.
+
+Examples
+--------
+
+Show the SQL that can be run to create the ``sf1`` schema::
+
+    SHOW CREATE SCHEMA hive.sf1;
+
+.. code-block:: none
+
+                  Create Schema
+    -----------------------------------------
+     CREATE SCHEMA hive.sf1
+     WITH (
+        location = 'hdfs://localhost:9000/user/hive/warehouse/sf1.db'
+     )
+    (1 row)
+
+See Also
+--------
+
+:doc:`create-schema`

Diff for: presto-hive/src/main/java/com/facebook/presto/hive/HiveMetadata.java

@@ -15,6 +15,7 @@
 
 import com.facebook.airlift.json.JsonCodec;
 import com.facebook.airlift.json.smile.SmileCodec;
+import com.facebook.presto.common.CatalogSchemaName;
 import com.facebook.presto.common.Subfield;
 import com.facebook.presto.common.predicate.NullableValue;
 import com.facebook.presto.common.predicate.TupleDomain;
@@ -65,6 +66,7 @@
 import com.facebook.presto.spi.PrestoException;
 import com.facebook.presto.spi.QueryId;
 import com.facebook.presto.spi.RecordCursor;
+import com.facebook.presto.spi.SchemaNotFoundException;
 import com.facebook.presto.spi.SchemaTableName;
 import com.facebook.presto.spi.SchemaTablePrefix;
 import com.facebook.presto.spi.SortingProperty;
@@ -201,6 +203,7 @@
 import static com.facebook.presto.hive.HivePartition.UNPARTITIONED_ID;
 import static com.facebook.presto.hive.HivePartitioningHandle.createHiveCompatiblePartitioningHandle;
 import static com.facebook.presto.hive.HivePartitioningHandle.createPrestoNativePartitioningHandle;
+import static com.facebook.presto.hive.HiveSchemaProperties.getDatabaseProperties;
 import static com.facebook.presto.hive.HiveSessionProperties.HIVE_STORAGE_FORMAT;
 import static com.facebook.presto.hive.HiveSessionProperties.RESPECT_TABLE_FORMAT;
 import static com.facebook.presto.hive.HiveSessionProperties.getBucketFunctionTypeForExchange;
@@ -502,6 +505,17 @@ public List<String> listSchemaNames(ConnectorSession session)
         return metastore.getAllDatabases(getMetastoreContext(session));
     }
 
+    @Override
+    public Map<String, Object> getSchemaProperties(ConnectorSession session, CatalogSchemaName schemaName)
+    {
+        MetastoreContext metastoreContext = getMetastoreContext(session);
+        Optional<Database> database = metastore.getDatabase(metastoreContext, schemaName.getSchemaName());
+        if (database.isPresent()) {
+            return getDatabaseProperties(database.get());
+        }
+        throw new SchemaNotFoundException(schemaName.getSchemaName());
+    }
+
     @Override
     public HiveTableHandle getTableHandle(ConnectorSession session, SchemaTableName tableName)
     {

Diff for: presto-hive/src/main/java/com/facebook/presto/hive/HiveSchemaProperties.java

@@ -13,8 +13,10 @@
  */
 package com.facebook.presto.hive;
 
+import com.facebook.presto.hive.metastore.Database;
 import com.facebook.presto.spi.session.PropertyMetadata;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
 
 import java.util.List;
 import java.util.Map;
@@ -39,4 +41,11 @@ public static Optional<String> getLocation(Map<String, Object> schemaProperties)
     {
         return Optional.ofNullable((String) schemaProperties.get(LOCATION_PROPERTY));
     }
+
+    public static Map<String, Object> getDatabaseProperties(Database database)
+    {
+        ImmutableMap.Builder<String, Object> result = ImmutableMap.builder();
+        database.getLocation().ifPresent(location -> result.put(LOCATION_PROPERTY, location));
+        return result.build();
+    }
 }

Diff for: presto-hive/src/test/java/com/facebook/presto/hive/TestHiveIntegrationSmokeTest.java

@@ -2781,6 +2781,20 @@ public void testShowCreateTable()
         actualResult = computeActual("SHOW CREATE TABLE \"test_show_create_table'2\"");
         assertEquals(getOnlyElement(actualResult.getOnlyColumnAsSet()), createTableSql);
     }
+    @Test
+    public void testShowCreateSchema()
+    {
+        String createSchemaSql = "CREATE SCHEMA show_create_hive_schema";
+        assertUpdate(createSchemaSql);
+        String expectedShowCreateSchema = "CREATE SCHEMA show_create_hive_schema\n" +
+                "WITH (\n" +
+                "   location = '.*show_create_hive_schema'\n" +
+                ")";
+
+        MaterializedResult actualResult = computeActual("SHOW CREATE SCHEMA show_create_hive_schema");
+        assertThat(getOnlyElement(actualResult.getOnlyColumnAsSet()).toString().matches(expectedShowCreateSchema));
+        assertUpdate("DROP SCHEMA show_create_hive_schema");
+    }
 
     @Test
     public void testTextfileAmbiguousTimestamp()

Diff for: presto-iceberg/src/main/java/com/facebook/presto/iceberg/IcebergHiveMetadata.java

@@ -14,6 +14,7 @@
 package com.facebook.presto.iceberg;
 
 import com.facebook.airlift.json.JsonCodec;
+import com.facebook.presto.common.CatalogSchemaName;
 import com.facebook.presto.common.type.Type;
 import com.facebook.presto.common.type.TypeManager;
 import com.facebook.presto.hive.HdfsContext;
@@ -87,6 +88,7 @@
 import java.util.TimeZone;
 import java.util.stream.Stream;
 
+import static com.facebook.presto.hive.HiveSchemaProperties.getDatabaseProperties;
 import static com.facebook.presto.hive.HiveStatisticsUtil.createPartitionStatistics;
 import static com.facebook.presto.hive.HiveStatisticsUtil.updatePartitionStatistics;
 import static com.facebook.presto.hive.HiveUtil.decodeViewData;
@@ -208,6 +210,17 @@ public List<String> listSchemaNames(ConnectorSession session)
         return metastore.getAllDatabases(getMetastoreContext(session));
     }
 
+    @Override
+    public Map<String, Object> getSchemaProperties(ConnectorSession session, CatalogSchemaName schemaName)
+    {
+        MetastoreContext metastoreContext = getMetastoreContext(session);
+        Optional<Database> database = metastore.getDatabase(metastoreContext, schemaName.getSchemaName());
+        if (database.isPresent()) {
+            return getDatabaseProperties(database.get());
+        }
+        throw new SchemaNotFoundException(schemaName.getSchemaName());
+    }
+
     @Override
     public List<SchemaTableName> listTables(ConnectorSession session, Optional<String> schemaName)
     {

Diff for: presto-iceberg/src/test/java/com/facebook/presto/iceberg/hive/TestIcebergSmokeHive.java

@@ -28,17 +28,21 @@
 import com.facebook.presto.iceberg.IcebergUtil;
 import com.facebook.presto.spi.ConnectorSession;
 import com.facebook.presto.spi.SchemaTableName;
+import com.facebook.presto.testing.MaterializedResult;
 import com.facebook.presto.tests.DistributedQueryRunner;
 import com.google.common.collect.ImmutableSet;
 import org.apache.iceberg.Table;
+import org.testng.annotations.Test;
 
 import java.io.File;
 import java.nio.file.Path;
 
 import static com.facebook.presto.hive.metastore.InMemoryCachingHiveMetastore.memoizeMetastore;
 import static com.facebook.presto.iceberg.CatalogType.HIVE;
 import static com.facebook.presto.iceberg.IcebergQueryRunner.getIcebergDataDirectoryPath;
+import static com.google.common.collect.Iterables.getOnlyElement;
 import static java.lang.String.format;
+import static org.assertj.core.api.Assertions.assertThat;
 
 public class TestIcebergSmokeHive
         extends IcebergDistributedSmokeTestBase
@@ -83,4 +87,19 @@ protected Table getIcebergTable(ConnectorSession session, String schema, String
                 session,
                 SchemaTableName.valueOf(schema + "." + tableName));
     }
+
+    @Test
+    public void testShowCreateSchema()
+    {
+        String createSchemaSql = "CREATE SCHEMA show_create_iceberg_schema";
+        assertUpdate(createSchemaSql);
+        String expectedShowCreateSchema = "CREATE SCHEMA show_create_iceberg_schema\n" +
+                "WITH (\n" +
+                "   location = '.*show_create_iceberg_schema'\n" +
+                ")";
+
+        MaterializedResult actualResult = computeActual("SHOW CREATE SCHEMA show_create_iceberg_schema");
+        assertThat(getOnlyElement(actualResult.getOnlyColumnAsSet()).toString().matches(expectedShowCreateSchema));
+        assertUpdate("DROP SCHEMA show_create_iceberg_schema");
+    }
 }

Diff for: presto-main/src/main/java/com/facebook/presto/metadata/DelegatingMetadataManager.java

@@ -95,6 +95,12 @@ public List<String> listSchemaNames(Session session, String catalogName)
         return delegate.listSchemaNames(session, catalogName);
     }
 
+    @Override
+    public Map<String, Object> getSchemaProperties(Session session, CatalogSchemaName schemaName)
+    {
+        return delegate.getSchemaProperties(session, schemaName);
+    }
+
     @Override
     public Optional<SystemTable> getSystemTable(Session session, QualifiedObjectName tableName)
     {

Diff for: presto-main/src/main/java/com/facebook/presto/metadata/Metadata.java

@@ -74,6 +74,11 @@ public interface Metadata
 
     List<String> listSchemaNames(Session session, String catalogName);
 
+    /**
+     * Gets the schema properties for the specified schema.
+     */
+    Map<String, Object> getSchemaProperties(Session session, CatalogSchemaName schemaName);
+
     Optional<SystemTable> getSystemTable(Session session, QualifiedObjectName tableName);
 
     /**

Diff for: presto-main/src/main/java/com/facebook/presto/metadata/MetadataManager.java

@@ -73,6 +73,7 @@
 import com.facebook.presto.spi.statistics.TableStatisticsMetadata;
 import com.facebook.presto.sql.analyzer.FeaturesConfig;
 import com.facebook.presto.sql.analyzer.FunctionsConfig;
+import com.facebook.presto.sql.analyzer.SemanticException;
 import com.facebook.presto.sql.analyzer.TypeSignatureProvider;
 import com.facebook.presto.transaction.TransactionManager;
 import com.facebook.presto.type.TypeDeserializer;
@@ -129,6 +130,7 @@
 import static com.facebook.presto.spi.StandardErrorCode.SYNTAX_ERROR;
 import static com.facebook.presto.spi.TableLayoutFilterCoverage.NOT_APPLICABLE;
 import static com.facebook.presto.spi.analyzer.ViewDefinition.ViewColumn;
+import static com.facebook.presto.sql.analyzer.SemanticErrorCode.MISSING_SCHEMA;
 import static com.facebook.presto.sql.analyzer.TypeSignatureProvider.fromTypes;
 import static com.facebook.presto.transaction.InMemoryTransactionManager.createTestTransactionManager;
 import static com.google.common.base.Preconditions.checkArgument;
@@ -318,6 +320,21 @@ public List<String> listSchemaNames(Session session, String catalogName)
         return ImmutableList.copyOf(schemaNames.build());
     }
 
+    @Override
+    public Map<String, Object> getSchemaProperties(Session session, CatalogSchemaName schemaName)
+    {
+        if (!getMetadataResolver(session).schemaExists(schemaName)) {
+            throw new SemanticException(MISSING_SCHEMA, format("Schema '%s' does not exist", schemaName));
+        }
+
+        Optional<CatalogMetadata> catalog = getOptionalCatalogMetadata(session, transactionManager, schemaName.getCatalogName());
+        CatalogMetadata catalogMetadata = catalog.get();
+        ConnectorSession connectorSession = session.toConnectorSession(catalogMetadata.getConnectorId());
+        ConnectorMetadata metadata = catalogMetadata.getMetadataFor(catalogMetadata.getConnectorId());
+
+        return metadata.getSchemaProperties(connectorSession, schemaName);
+    }
+
     @Override
     public Optional<TableHandle> getTableHandleForStatisticsCollection(Session session, QualifiedObjectName table, Map<String, Object> analyzeProperties)
     {

Diff for: presto-main/src/main/java/com/facebook/presto/sql/rewrite/ShowQueriesRewrite.java

@@ -53,6 +53,7 @@
 import com.facebook.presto.sql.tree.ConstraintSpecification;
 import com.facebook.presto.sql.tree.CreateFunction;
 import com.facebook.presto.sql.tree.CreateMaterializedView;
+import com.facebook.presto.sql.tree.CreateSchema;
 import com.facebook.presto.sql.tree.CreateTable;
 import com.facebook.presto.sql.tree.CreateView;
 import com.facebook.presto.sql.tree.DoubleLiteral;
@@ -113,10 +114,12 @@
 import static com.facebook.presto.metadata.MetadataUtil.createCatalogSchemaName;
 import static com.facebook.presto.metadata.MetadataUtil.createQualifiedName;
 import static com.facebook.presto.metadata.MetadataUtil.createQualifiedObjectName;
+import static com.facebook.presto.metadata.MetadataUtil.getConnectorIdOrThrow;
 import static com.facebook.presto.metadata.SessionFunctionHandle.SESSION_NAMESPACE;
 import static com.facebook.presto.spi.StandardErrorCode.FUNCTION_NOT_FOUND;
 import static com.facebook.presto.spi.StandardErrorCode.GENERIC_USER_ERROR;
 import static com.facebook.presto.spi.StandardErrorCode.INVALID_COLUMN_PROPERTY;
+import static com.facebook.presto.spi.StandardErrorCode.INVALID_SCHEMA_PROPERTY;
 import static com.facebook.presto.spi.StandardErrorCode.INVALID_TABLE_PROPERTY;
 import static com.facebook.presto.sql.ExpressionUtils.combineConjuncts;
 import static com.facebook.presto.sql.QueryUtil.aliased;
@@ -151,6 +154,7 @@
 import static com.facebook.presto.sql.tree.RoutineCharacteristics.Language;
 import static com.facebook.presto.sql.tree.RoutineCharacteristics.NullCallClause;
 import static com.facebook.presto.sql.tree.ShowCreate.Type.MATERIALIZED_VIEW;
+import static com.facebook.presto.sql.tree.ShowCreate.Type.SCHEMA;
 import static com.facebook.presto.sql.tree.ShowCreate.Type.TABLE;
 import static com.facebook.presto.sql.tree.ShowCreate.Type.VIEW;
 import static com.facebook.presto.util.AnalyzerUtil.createParsingOptions;
@@ -581,6 +585,22 @@ else if (constraint instanceof UniqueConstraint) {
                 return singleValueQuery("Create Table", formatSql(createTable, Optional.of(parameters)).trim());
             }
 
+            if (node.getType() == SCHEMA) {
+                CatalogSchemaName catalogSchemaName = createCatalogSchemaName(session, node, Optional.of(node.getName()));
+                if (!metadataResolver.schemaExists(catalogSchemaName)) {
+                    throw new SemanticException(MISSING_SCHEMA, node, "Schema '%s' does not exist", catalogSchemaName);
+                }
+
+                Map<String, Object> properties = metadata.getSchemaProperties(session, catalogSchemaName);
+                Map<String, PropertyMetadata<?>> allTableProperties = metadata.getSchemaPropertyManager().getAllProperties().get(getConnectorIdOrThrow(session, metadata, catalogSchemaName.getCatalogName()));
+                List<Property> propertyNodes = buildProperties(objectName, Optional.empty(), INVALID_SCHEMA_PROPERTY, properties, allTableProperties);
+                CreateSchema createSchema = new CreateSchema(
+                        node.getName(),
+                        false,
+                        propertyNodes);
+                return singleValueQuery("Create Schema", formatSql(createSchema, Optional.of(parameters)).trim());
+            }
+
             throw new UnsupportedOperationException("SHOW CREATE only supported for tables and views");
         }
 

Diff for: presto-main/src/test/java/com/facebook/presto/metadata/AbstractMockMetadata.java

@@ -140,6 +140,12 @@ public List<String> listSchemaNames(Session session, String catalogName)
         throw new UnsupportedOperationException();
     }
 
+    @Override
+    public Map<String, Object> getSchemaProperties(Session session, CatalogSchemaName schemaName)
+    {
+        throw new UnsupportedOperationException();
+    }
+
     @Override
     public Optional<TableHandle> getTableHandleForStatisticsCollection(Session session, QualifiedObjectName tableName, Map<String, Object> analyzeProperties)
     {

Diff for: presto-parser/src/main/antlr4/com/facebook/presto/sql/parser/SqlBase.g4

@@ -118,6 +118,7 @@ statement
     | EXPLAIN ANALYZE? VERBOSE?
         ('(' explainOption (',' explainOption)* ')')? statement        #explain
     | SHOW CREATE TABLE qualifiedName                                  #showCreateTable
+    | SHOW CREATE SCHEMA qualifiedName                                 #showCreateSchema
     | SHOW CREATE VIEW qualifiedName                                   #showCreateView
     | SHOW CREATE MATERIALIZED VIEW qualifiedName                      #showCreateMaterializedView
     | SHOW CREATE FUNCTION qualifiedName types?                        #showCreateFunction

Diff for: presto-parser/src/main/java/com/facebook/presto/sql/SqlFormatter.java

@@ -858,6 +858,10 @@ protected Void visitShowCreate(ShowCreate node, Integer context)
                 builder.append("SHOW CREATE TABLE ")
                         .append(formatName(node.getName()));
             }
+            else if (node.getType() == ShowCreate.Type.SCHEMA) {
+                builder.append("SHOW CREATE SCHEMA ")
+                        .append(formatName(node.getName()));
+            }
             else if (node.getType() == ShowCreate.Type.VIEW) {
                 builder.append("SHOW CREATE VIEW ")
                         .append(formatName(node.getName()));

Diff for: presto-parser/src/main/java/com/facebook/presto/sql/parser/AstBuilder.java

@@ -375,6 +375,12 @@ public Node visitShowCreateTable(SqlBaseParser.ShowCreateTableContext context)
         return new ShowCreate(getLocation(context), ShowCreate.Type.TABLE, getQualifiedName(context.qualifiedName()));
     }
 
+    @Override
+    public Node visitShowCreateSchema(SqlBaseParser.ShowCreateSchemaContext context)
+    {
+        return new ShowCreate(getLocation(context), ShowCreate.Type.SCHEMA, getQualifiedName(context.qualifiedName()));
+    }
+
     @Override
     public Node visitShowCreateFunction(SqlBaseParser.ShowCreateFunctionContext context)
     {

Diff for: presto-parser/src/main/java/com/facebook/presto/sql/tree/ShowCreate.java

@@ -28,6 +28,7 @@ public class ShowCreate
     public enum Type
     {
         TABLE,
+        SCHEMA,
         VIEW,
         MATERIALIZED_VIEW
     }