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ASF GitHub Bot commented on DRILL-4514: --------------------------------------- Github user arina-ielchiieva commented on a diff in the pull request: https://github.com/apache/drill/pull/436#discussion_r56957772 --- Diff: exec/java-exec/src/main/java/org/apache/drill/exec/planner/sql/parser/SqlDescribeSchema.java --- @@ -0,0 +1,82 @@ +/** + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * <p/> + * http://www.apache.org/licenses/LICENSE-2.0 + * <p/> + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.drill.exec.planner.sql.parser; + +import org.apache.calcite.sql.SqlCall; +import org.apache.calcite.sql.SqlIdentifier; +import org.apache.calcite.sql.SqlKind; +import org.apache.calcite.sql.SqlLiteral; +import org.apache.calcite.sql.SqlNode; +import org.apache.calcite.sql.SqlOperator; +import org.apache.calcite.sql.SqlSpecialOperator; +import org.apache.calcite.sql.SqlWriter; +import org.apache.calcite.sql.parser.SqlParserPos; +import org.apache.drill.exec.planner.sql.handlers.AbstractSqlHandler; +import org.apache.drill.exec.planner.sql.handlers.DescribeSchemaHandler; +import org.apache.drill.exec.planner.sql.handlers.SqlHandlerConfig; + +import java.util.Collections; +import java.util.List; + +/** + * Sql parse tree node to represent statement: + * SHOW FILES [{FROM | IN} db_name] [LIKE 'pattern' | WHERE expr] + */ +public class SqlDescribeSchema extends DrillSqlCall { + + private final SqlIdentifier schema; + + public static final SqlSpecialOperator OPERATOR = + new SqlSpecialOperator("DESCRIBE_SCHEMA", SqlKind.OTHER) { + @Override + public SqlCall createCall(SqlLiteral functionQualifier, SqlParserPos pos, SqlNode... operands) { + return new SqlDescribeSchema(pos, (SqlIdentifier) operands[0]); + } + }; + + public SqlDescribeSchema(SqlParserPos pos, SqlIdentifier schema) { + super(pos); + this.schema = schema; + assert schema != null; --- End diff -- Agree, preconditions is better. But I have checked that schema can't come as null, so I have removed check for not null at all. > Add describe schema <schema_name> command > ----------------------------------------- > > Key: DRILL-4514 > URL: https://issues.apache.org/jira/browse/DRILL-4514 > Project: Apache Drill > Issue Type: New Feature > Affects Versions: Future > Reporter: Arina Ielchiieva > Assignee: Arina Ielchiieva > > Add describe database <db_name> command which will return directory > associated with a database on the fly. > Syntax: > describe database <db_name> > describe schema <schema_name> > Output: > {noformat} > DESCRIBE SCHEMA xdf.proc; > +---------------------+----------------------------+ > | name | location | > +---------------------+----------------------------+ > | xdf.proc | maprfs://dl.data/processed | > +---------------------+----------------------------+ > {noformat} > Current implementation covers only dfs schema. > For all other "<INFORMATION UNAVAILABLE>" will be returned. -- This message was sent by Atlassian JIRA (v6.3.4#6332)