Implement DropIndex

DropIndex by Index Name method implemented in Catalog class.
Test Added for DropIndex

Author: dasdipanjan04

src/catalog/catalog.cpp

@@ -374,10 +374,8 @@ ResultType Catalog::CreateIndex(const std::string &database_name,
   if (txn == nullptr)
     throw CatalogException("Do not have transaction to create database " +
                            index_name);
-
   LOG_TRACE("Trying to create index %s for table %s", index_name.c_str(),
             table_name.c_str());
-
   // check if database exists
   auto database_object =
       DatabaseCatalog::GetInstance()->GetDatabaseObject(database_name, txn);
@@ -393,11 +391,9 @@ ResultType Catalog::CreateIndex(const std::string &database_name,
 
   IndexConstraintType index_constraint =
       unique_keys ? IndexConstraintType::UNIQUE : IndexConstraintType::DEFAULT;
-
   ResultType success = CreateIndex(
       database_object->GetDatabaseOid(), table_object->GetTableOid(), key_attrs,
       index_name, index_type, index_constraint, unique_keys, txn);
-
   return success;
 }
 
@@ -612,8 +608,22 @@ ResultType Catalog::DropIndex(oid_t index_oid,
   return ResultType::SUCCESS;
 }
 
+ResultType Catalog::DropIndex(const std::string &index_name,
+                              concurrency::TransactionContext *txn){
+    if(txn == nullptr){
+        throw CatalogException("Do not have transaction to drop index " + index_name);
+    }
+    auto index_object = catalog::IndexCatalog::GetInstance()->GetIndexObject(index_name,txn);
+    if(index_object == nullptr){
+        throw CatalogException("Index name " + index_name + " cannot be found");
+    }
+    ResultType result = DropIndex(index_object->GetIndexOid(),txn);
+
+    return result;
+}
+
 //===--------------------------------------------------------------------===//
-// GET WITH NAME - CHECK FROM CATALOG TABLES, USING TRANSACTION
+// GET WITH NAME - CHECK FROM CATALOG TABLES, USING TRANSACTION             //
 //===--------------------------------------------------------------------===//
 
 /* Check database from pg_database with database_name using txn,

src/include/catalog/catalog.h

@@ -23,6 +23,7 @@ namespace catalog {
 class Schema;
 class DatabaseCatalogObject;
 class TableCatalogObject;
+class IndexCatalogObject;
 }  // namespace catalog
 
 namespace concurrency {
@@ -134,6 +135,9 @@ class Catalog {
   // Drop an index, using its index_oid
   ResultType DropIndex(oid_t index_oid, concurrency::TransactionContext *txn);
 
+  // Drop an index, using its index name
+  ResultType DropIndex(const std::string &index_name,
+                       concurrency::TransactionContext *txn);
   //===--------------------------------------------------------------------===//
   // GET WITH NAME - CHECK FROM CATALOG TABLES, USING TRANSACTION
   //===--------------------------------------------------------------------===//
@@ -173,6 +177,11 @@ class Catalog {
       oid_t database_oid, oid_t table_oid,
       concurrency::TransactionContext *txn);
 
+
+
+ std::shared_ptr<IndexCatalogObject> GetIndexObject(
+         const std::string &database_name, const std::string &index_name, const std::string &table_name,
+         concurrency::TransactionContext *txn);
   //===--------------------------------------------------------------------===//
   // DEPRECATED FUNCTIONS
   //===--------------------------------------------------------------------===//

test/executor/drop_test.cpp

@@ -13,7 +13,7 @@
 #include <cstdio>
 
 #include "gtest/gtest.h"
-
+#include "catalog/index_catalog.h"
 #include "catalog/catalog.h"
 #include "catalog/database_catalog.h"
 #include "common/harness.h"
@@ -219,5 +219,52 @@ TEST_F(DropTests, DroppingTrigger) {
   txn_manager.CommitTransaction(txn);
 }
 
+TEST_F(DropTests, DroppingIndexByName) {
+  auto catalog = catalog::Catalog::GetInstance();
+  catalog->Bootstrap();
+
+  auto &txn_manager = concurrency::TransactionManagerFactory::GetInstance();
+
+  auto txn = txn_manager.BeginTransaction();
+  catalog->CreateDatabase(TEST_DB_NAME, txn);
+  auto db = catalog->GetDatabaseWithName(TEST_DB_NAME, txn);
+
+  // Insert a table first
+  auto id_column = catalog::Column(
+      type::TypeId::INTEGER, type::Type::GetTypeSize(type::TypeId::INTEGER),
+      "dept_id", true);
+  auto name_column =
+      catalog::Column(type::TypeId::VARCHAR, 32, "dept_name", false);
+
+
+  std::unique_ptr<catalog::Schema> table_schema(
+      new catalog::Schema({id_column, name_column}));
+  std::unique_ptr<catalog::Schema> table_schema2(
+      new catalog::Schema({id_column, name_column}));
+
+  catalog->CreateTable(TEST_DB_NAME, "department_table_01", std::move(table_schema),
+                       txn);
+
+  auto source_table = db->GetTableWithName("department_table_01");
+  oid_t col_id = source_table->GetSchema()->GetColumnID(id_column.column_name);
+  std::vector<oid_t> source_col_ids;
+  source_col_ids.push_back(col_id);
+  std::string index_name1 = "pg_table_pkey";
+  catalog->CreateIndex(TEST_DB_NAME, "department_table_01",
+                       source_col_ids, index_name1, false,
+                       IndexType::BWTREE, txn);
+
+  auto index_catalog = catalog::IndexCatalog::GetInstance()->GetIndexObject(index_name1, txn);
+  auto index_oid = index_catalog->GetIndexOid();
+  catalog->DropIndex(index_oid,txn);
+
+  std::string index_name2 = "pg_database_pkey";
+  catalog->CreateIndex(TEST_DB_NAME, "department_table_01",
+                       source_col_ids, index_name2, false,
+                       IndexType::BWTREE, txn);
+  catalog->DropIndex(index_name2,txn);
+
+  txn_manager.CommitTransaction(txn);
+}
 }  // namespace test
 }  // namespace peloton