uqa-engine 0.2.3

Engine: schema-aware table store, catalog restore, transactions
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
133
134
135
136
137
138
139
140
141
142

//
// Unified Query Algebra
//
// Copyright (c) 2023-2026 Cognica, Inc.
//

//! Stored index semantics and the common key-enforcement boundary.

use crate::engine_capabilities::RelationLookupMode;
use crate::{CatalogIndexRow, Engine, StorageBackendError, StorageBackendResult};
use uqa_sql::ast::{Expr, IndexKey, TableKeyConstraint, TableKeyConstraintKind};

#[derive(Debug, Clone, Default, PartialEq, serde::Serialize, serde::Deserialize)]
#[serde(deny_unknown_fields)]
pub(crate) struct IndexDefinition {
    #[serde(default)]
    pub(crate) included_columns: Vec<String>,
    #[serde(default)]
    pub(crate) column_order: Vec<uqa_sql::ast::IndexColumnOrder>,
    #[serde(default)]
    pub(crate) key_names: Vec<String>,
    #[serde(default)]
    pub(crate) key_types: Vec<uqa_sql::ast::ColumnType>,
    #[serde(default)]
    pub(crate) predicate: Option<Box<Expr>>,
    pub(crate) unique: bool,
    pub(crate) nulls_not_distinct: bool,
}

pub(crate) fn index_definition(index: &CatalogIndexRow) -> StorageBackendResult<IndexDefinition> {
    index.definition_json.as_deref().map_or_else(
        || Ok(IndexDefinition::default()),
        |definition| serde_json::from_str(definition).map_err(StorageBackendError::from),
    )
}

impl Engine {
    /// Key descriptors used by row validation, key reservations, and conflict arbitration. Standalone unique indexes remain independent catalog objects and do not create SQL constraints.
    pub(crate) fn enforced_keys(&self, table: &str) -> StorageBackendResult<Vec<EnforcedKey>> {
        let mut keys = self
            .try_key_constraints(table)?
            .into_iter()
            .map(EnforcedKey::from)
            .collect::<Vec<_>>();
        let table = self
            .try_resolve_table_name(table)?
            .ok_or_else(|| StorageBackendError::Other(format!("table `{table}` does not exist")))?;
        let catalog = self.catalog_read_view();
        let mut resolution = self.session_execution_view().relation_name_resolution();
        resolution.set_lookup_mode(RelationLookupMode::Bound);
        for index in catalog.catalog_indexes() {
            let definition = index_definition(index)?;
            if !definition.unique {
                continue;
            }
            let applies = if index.table_name == table {
                true
            } else {
                let source = catalog
                    .table_resolved(&resolution, &index.table_name)
                    .map_err(|error| StorageBackendError::Other(error.to_string()))?;
                source.is_some_and(|source| source.hierarchy.partition_spec.is_some())
                    && catalog
                        .hierarchy_scan_tables(&resolution, &index.table_name, true)
                        .map_err(|error| StorageBackendError::Other(error.to_string()))?
                        .contains(&table)
            };
            if applies {
                let index_keys: Vec<IndexKey> = serde_json::from_str(&index.columns_json)?;
                keys.push(EnforcedKey {
                    index: Some(index.relation.clone()),
                    keys: index_keys.clone(),
                    predicate: definition.predicate,
                    constraint_owned: false,
                    constraint: TableKeyConstraint {
                        name: Some(index.relation.name.clone()),
                        kind: TableKeyConstraintKind::Unique,
                        columns: index_keys
                            .iter()
                            .filter_map(IndexKey::column)
                            .map(str::to_owned)
                            .collect(),
                        nulls_not_distinct: definition.nulls_not_distinct,
                        without_overlaps: false,
                    },
                });
            }
        }
        Ok(keys)
    }
}

/// Runtime key enforcement keeps index predicates separate from SQL constraints.
#[derive(Debug, Clone)]
pub(crate) struct EnforcedKey {
    pub(crate) constraint: TableKeyConstraint,
    pub(crate) keys: Vec<IndexKey>,
    pub(crate) index: Option<crate::RelationIdentity>,
    pub(crate) predicate: Option<Box<Expr>>,
    pub(crate) constraint_owned: bool,
}

impl std::ops::Deref for EnforcedKey {
    type Target = TableKeyConstraint;

    fn deref(&self) -> &Self::Target {
        &self.constraint
    }
}

impl From<TableKeyConstraint> for EnforcedKey {
    fn from(constraint: TableKeyConstraint) -> Self {
        Self {
            keys: constraint
                .columns
                .iter()
                .cloned()
                .map(IndexKey::Column)
                .collect(),
            index: None,
            constraint,
            predicate: None,
            constraint_owned: true,
        }
    }
}

impl Engine {
    pub(crate) fn referenceable_keys(
        &self,
        table: &str,
    ) -> StorageBackendResult<Vec<TableKeyConstraint>> {
        Ok(self
            .enforced_keys(table)?
            .into_iter()
            .filter(|key| {
                key.predicate.is_none() && key.keys.iter().all(|key| key.column().is_some())
            })
            .map(|key| key.constraint)
            .collect())
    }
}