Database-Engine

Overview

This project is a mini database engine implemented in Java. It provides basic database operations such as insertions, deletions, updates, and select operations. The project also uses B+Trees to optimize the performance of select queries.

• Supports 3 datatypes (Strings, Integers, Doubles).
• Stores tables, pages and indicies in serialized object files.
• Stores page ranges (min and max clustering key of each page) for each table.
• Supports fast equality and range queries by maintaining a balanced B+Tree on desired column.
• Saves metadata about tables in a CSV format, and uses Singleton design pattern to maintain a single instance of the Metadata class throughout its usage.

Supported Operations

• Insertions
  • Runs in O(N * log N) to keep tuples sorted based on the table clustering key.
  • Finds appropriate insertion position by binary search on page ranges.
• Deletions
  • Runs in O(log N) when deleting by clustering key or an indexed column.
  • Runs in O(N) otherwise.
• Updates
  • Runs in O(N) to search for the tuple and update it.
• Select
  • Time complexity of O(K + log N) for range queries on indexed columns.
  • N represents the total number of data items stored in the B+Tree.
  • K represents the number of data items found within the specified range.
  • Supports operators (=, !=, >, >=, <, <=) for each condition, and logical operators (AND, OR, XOR) between multiple conditions.

Technologies used

1. Java
2. Maven