KAWULASQL - Query Processor Component

Table of Contents

• General Info
• Class Descriptions
• Technologies Used
• Setup and Usage
• Team Members

General Info

This component integrates all components of the DBMS. It accepts a query as input, then executes it by processing it through multiple components.

Class Overview

1. QueryProcessor The QueryProcessor class serves as an intermediary to the QueryExecutor class. It identifies the type of the query, then executes it by calling the QueryExecutor. The functions of this class include:

   • process_query(str):
     • Identifies the type of the query from the query string.
     • Executes the query by calling the QueryExecutor according to the query type.

2. QueryExecutor The function of the QueryExecutor class is to execute the query by communicating directly with the Query Optimizer, Storage Manager, Failure Recovery Manager, and Concurrency Control Manager components. The functions of this class include:

   • execute_select(str) -> ExecutionResult:
     • Identifies the type of the query from the query string.
     • Executes the query by calling the QueryExecutor according to the query type.
   • execute_select(str) -> ExecutionResult:
     • Entry point to the execute_query function.
     • Parses the query by passing it to the QueryOptimizer component
     • Obtains the QueryTree from the parse result and passes it to the execute_query function.
   • execute_query(QueryTree) -> Tuple[list, list, map]:
     • Iterates through a Query Tree and process each operation according to the type of node.
   • execute_insert(str) -> ExecutionResult:
     • Parses and executes an insert query
     • Calls the Storage Manager component to insert the parsed list of records
   • execute_create(str) -> ExecutionResult:
     • Parses and executes a Create Table query
     • Calls the Storage Manager component to create the parsed table and schema
   • execute_update(str) -> ExecutionResult:
     • Parses and executes an UPDATE query
     • Calls the Storage Manager component to update the parsed list of records
   • execute_delete(str) -> ExecutionResult:
     • Parses and executes a DELETE FROM query
     • Calls the Storage Manager component to delete the parsed list of records
   • execute_drop(str) -> ExecutionResult:
     • Parses and executes a DROP query
     • Calls the Storage Manager to drop the parsed name of table

3. Rows The Rows class stores a list of records/tuples/rows along with other necessary information. Attributes include:

   • data: Is the list of data containing the values of the record.
   • rows_count: Specifies the number of rows.
   • schema: Defines the schema for each records.
   • columns: Maps attributes/columns in the row to its type.

4. ExecutionResult The ExecutionResult class stores information about the result of the query. Attributes include:

   • transaction_id: Specifies the id of the transaction.
   • timestamp: Specifies the timestamp of the transaction.
   • status: Specifies the status of the execution result (error/success).
   • query: Specifies the query string.
   • previous_data: Specifies the data before the execution of the query.
   • new_data: Specifies the data after the execution of the query.

Technologies Used

• Python 3

Setup and Usage

1. Clone this project:

https://github.com/KawulaSQL/Query_Processor.git

2. To run unit tests, execute the following command from the root directory:

python -m unittest UnitTest.py

Team Members

Nama	NIM	Workload
Ariel Herfrison	13522002	unit test, client
Farhan Nafis Rayhan	13522037	cli, unit test, client
Randy Verdian	13522067	execute_select, execute_query
Marvin Scifo Y. Hutahaean	13522110	concurrency control Integration