supertable_core/
optimize.rs

1//! # Table Optimization
2//!
3//! This module provides tools for optimizing table layout, such as compacting small files
4//! (bin-packing) and sorting data (Z-Ordering).
5
6use crate::table::Table;
7use crate::transaction::Transaction;
8use anyhow::Result;
9
10/// Options for compaction.
11#[derive(Debug, Clone)]
12pub struct CompactOptions {
13    /// Target file size in bytes (e.g., 128MB).
14    pub target_size_bytes: u64,
15    /// Minimum number of files to trigger compaction.
16    pub min_files_to_compact: usize,
17    /// Filter for compaction
18    pub filter: Option<String>,
19}
20
21impl Default for CompactOptions {
22    fn default() -> Self {
23        Self {
24            target_size_bytes: 128 * 1024 * 1024,
25            min_files_to_compact: 5,
26            filter: None,
27        }
28    }
29}
30
31/// Scheduler for running compaction tasks.
32pub struct CompactionScheduler {
33    // Placeholder for scheduler state
34}
35
36impl CompactionScheduler {
37    pub fn new() -> Self {
38        Self {}
39    }
40
41    pub async fn schedule_compaction(&self, _table: &Table) -> Result<()> {
42        // Placeholder
43        Ok(())
44    }
45}
46
47/// Strategy for compaction.
48#[derive(Debug, Clone)]
49pub enum CompactionStrategy {
50    /// Combines small files into larger ones.
51    BinPack,
52    /// Sorts data by specific columns (e.g., Z-Order).
53    Sort {
54        /// Columns to sort by.
55        sort_columns: Vec<String>,
56    },
57}
58
59/// Main optimizer entry point.
60pub struct Optimizer {
61    table: Table,
62    options: CompactOptions,
63    strategy: CompactionStrategy,
64}
65
66impl Optimizer {
67    pub fn new(table: Table) -> Self {
68        Self {
69            table,
70            options: CompactOptions::default(),
71            strategy: CompactionStrategy::BinPack,
72        }
73    }
74
75    /// Sets the compaction options.
76    pub fn with_options(mut self, options: CompactOptions) -> Self {
77        self.options = options;
78        self
79    }
80
81    /// Sets the compaction strategy.
82    pub fn with_strategy(mut self, strategy: CompactionStrategy) -> Self {
83        self.strategy = strategy;
84        self
85    }
86
87    /// Executes the optimization.
88    pub async fn execute(self) -> Result<Transaction> {
89        let snapshot = self.table.metadata.current_snapshot();
90        if snapshot.is_none() {
91            return Ok(self.table.new_transaction());
92        }
93        let snapshot = snapshot.unwrap();
94
95        let all_files = snapshot.all_data_files(&self.table.storage).await?;
96
97        // Filter files based on self.filter (Placeholder)
98        // Identify small files
99
100        let mut files_to_compact = Vec::new();
101        // let mut other_files = Vec::new();
102
103        let target_size = self.options.target_size_bytes;
104
105        for file in all_files {
106            if (file.file_size_in_bytes as u64) < target_size {
107                files_to_compact.push(file);
108            } else {
109                // other_files.push(file);
110            }
111        }
112
113        if files_to_compact.len() < self.options.min_files_to_compact {
114            return Ok(self.table.new_transaction());
115        }
116
117        // Implementation limitation:
118        // Real compaction requires reading these files, merging them, and writing new ones.
119        // For this prototype, we will just return a transaction that *would* replace them,
120        // but since we can't easily read/write locally without full context, we'll
121        // leave it as a placeholder that does no-op but compiles.
122
123        // In a real implementation:
124        // 1. Group files into bins of target_size
125        // 2. Read each bin -> RecordBatch
126        // 3. Write RecordBatch -> New DataFile
127        // 4. Create Transaction: Remove old files, Add new files
128
129        let tx = self.table.new_transaction();
130        // tx.remove_files(files_to_compact.iter().map(|f| f.file_path.clone()).collect());
131        // tx.add_files(new_files);
132
133        Ok(tx)
134    }
135}
supertable_core/optimize.rs

supertable_core/
optimize.rs
