motedb 0.1.2

AI-native embedded multimodal database for embodied intelligence (robots, AR glasses, industrial arms).
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132

//! Query planner and optimizer

use crate::Result;

/// Operator types in execution plan
#[derive(Debug, Clone)]
pub enum Operator {
    /// Full table scan
    Scan { source: String },
    /// Filter operation
    Filter { predicate: String },
    /// Projection operation
    Project { columns: Vec<String> },
    /// Index scan
    IndexScan { index_type: String, range: String },
    /// Join operation
    Join { left: Box<ExecutionPlan>, right: Box<ExecutionPlan> },
}

/// Execution plan tree
#[derive(Debug, Clone)]
pub struct ExecutionPlan {
    /// Root operator
    pub operator: Operator,
    /// Child plans
    pub children: Vec<ExecutionPlan>,
    /// Estimated cost
    pub cost: f64,
}

impl ExecutionPlan {
    /// Create a simple scan plan
    pub fn scan(source: String) -> Self {
        Self {
            operator: Operator::Scan { source },
            children: Vec::new(),
            cost: 100.0,
        }
    }
    
    /// Create an index scan plan
    pub fn index_scan(index_type: String, range: String) -> Self {
        Self {
            operator: Operator::IndexScan { index_type, range },
            children: Vec::new(),
            cost: 10.0, // Index scan is cheaper
        }
    }
    
    /// Add a filter operator
    pub fn with_filter(self, predicate: String) -> Self {
        
        Self {
            operator: Operator::Filter { predicate },
            children: vec![self.clone()],
            cost: self.cost + 5.0,
        }
    }
    
    /// Add a projection operator
    pub fn with_project(self, columns: Vec<String>) -> Self {
        
        Self {
            operator: Operator::Project { columns },
            children: vec![self.clone()],
            cost: self.cost + 1.0,
        }
    }
}

/// Query planner - converts SQL/API queries to execution plans
pub struct QueryPlanner {
    /// Enable query optimization
    enable_optimization: bool,
}

impl QueryPlanner {
    /// Create a new query planner
    pub fn new() -> Result<Self> {
        Ok(Self {
            enable_optimization: true,
        })
    }
    
    /// Create with optimization disabled (for testing)
    pub fn without_optimization() -> Result<Self> {
        Ok(Self {
            enable_optimization: false,
        })
    }
    
    /// Plan a simple range query
    pub fn plan_range_query(&self, index_type: &str, start: i64, end: i64) -> Result<ExecutionPlan> {
        let range = format!("[{}, {})", start, end);
        
        if self.enable_optimization && self.should_use_index(index_type) {
            // Use index scan
            Ok(ExecutionPlan::index_scan(index_type.to_string(), range))
        } else {
            // Fallback to full scan with filter
            Ok(ExecutionPlan::scan("default".to_string())
                .with_filter(format!("timestamp BETWEEN {} AND {}", start, end)))
        }
    }
    
    /// Determine if index should be used
    fn should_use_index(&self, _index_type: &str) -> bool {
        // Future: Consider selectivity, cost model, statistics
        true
    }
    
    /// Optimize an execution plan
    pub fn optimize(&self, plan: ExecutionPlan) -> Result<ExecutionPlan> {
        if !self.enable_optimization {
            return Ok(plan);
        }
        
        // Future optimizations:
        // - Predicate pushdown
        // - Column pruning
        // - Index selection
        // - Join reordering
        
        Ok(plan)
    }
}

impl Default for QueryPlanner {
    fn default() -> Self {
        Self::new().unwrap()
    }
}