Module storage_engine 

StorageEngine Trait Abstraction (Task 1)

Decouples the query engine from concrete storage implementations. Enables pluggable backends: LSMTree for compatibility, Lscs for columnar TOON workloads.

I/O Reduction Model

Traditional Row I/O: O(N × K) where N=rows, K=total columns
Columnar I/O:        O(N × k) where k=selected columns

For k/K = 0.2 (typical TOON projection):
I/O_reduction = 1 - (k/K) = 80%

Structs

ColumnIterator

Iterator over columns

LscsAdapter

Adapter to make Lscs implement StorageEngine

Row

A row of data with column values

StorageStats

Storage engine statistics

TxnHandle

Transaction handle for ACID operations

Enums

StorageEngineType

Storage engine types

Traits

StorageEngine

StorageEngine trait - the core abstraction for pluggable storage backends

Functions

open_storage_engine

Open a storage engine from a path

Type Aliases

ColumnId

Column identifier

RowId

Row identifier