Oracle MCP Server

Instructions

Implementation Reference

• src/oracle_mcp_server/server.py:465-517 (handler)

  Core implementation of the explain_query tool. Executes EXPLAIN PLAN for the given SQL, retrieves the hierarchical execution plan from plan_table, formats it, cleans up the plan_table entry, and returns the plan details.
  async def explain_query(self, sql: str) -> Dict[str, Any]: """Get execution plan for a query""" conn = await self.connection_manager.get_connection() try: cursor = conn.cursor() # Generate unique statement ID statement_id = f"MCP_EXPLAIN_{datetime.now().strftime('%Y%m%d_%H%M%S')}" # Explain the plan explain_sql = f"EXPLAIN PLAN SET STATEMENT_ID = '{statement_id}' FOR {sql}" cursor.execute(explain_sql) # Fetch the execution plan plan_query = """ SELECT LPAD(' ', 2 * (LEVEL - 1)) || operation || ' ' || options AS operation, object_name, cost, cardinality, bytes FROM plan_table WHERE statement_id = :statement_id START WITH id = 0 CONNECT BY PRIOR id = parent_id AND statement_id = :statement_id ORDER BY id """ cursor.execute(plan_query, [statement_id, statement_id]) plan_rows = [] for row in cursor: plan_rows.append( { "operation": row[0], "object_name": row[1], "cost": row[2], "cardinality": row[3], "bytes": row[4], } ) # Clean up cursor.execute( "DELETE FROM plan_table WHERE statement_id = :statement_id", [statement_id], ) conn.commit() return {"execution_plan": plan_rows, "statement_id": statement_id} finally: conn.close()
• src/oracle_mcp_server/server.py:709-722 (registration)

  Registers the 'explain_query' tool with the MCP server, defining its name, description, and input schema.
  Tool( name="explain_query", description="Get the execution plan for a SQL query to analyze performance", inputSchema={ "type": "object", "properties": { "sql": { "type": "string", "description": "SQL query to explain", } }, "required": ["sql"], }, ),
• src/oracle_mcp_server/server.py:835-843 (handler)

  MCP tool dispatcher handler that handles 'explain_query' calls by extracting the SQL argument and invoking the QueryExecutor's explain_query method, then serializing and returning the result as TextContent.
  elif name == "explain_query": sql = arguments.get("sql") result = await self.executor.explain_query(sql) return [ TextContent( type="text", text=json.dumps(result, indent=2, default=str) ) ]
• src/oracle_mcp_server/server.py:712-721 (schema)

  Defines the input schema for the 'explain_query' tool, requiring a 'sql' string parameter.
  inputSchema={ "type": "object", "properties": { "sql": { "type": "string", "description": "SQL query to explain", } }, "required": ["sql"], },