uqa-execution 0.4.6

Volcano physical operators with row-batch pipelines
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

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

//! Reconstruct typed array access without confusing its display name with a SQL routine.

use std::fmt::Write as _;
use uqa_core::Value;
use uqa_sql::{ast::FunctionDispatch, ir::ScalarExpr, plan::QueryPlan, SQLError};

use super::{Deparser, Scope};

impl Deparser<'_> {
    pub(super) fn array_subscripts(
        &self,
        dispatch: FunctionDispatch,
        args: &[ScalarExpr],
        scope: &Scope,
        subqueries: &[QueryPlan],
    ) -> Result<String, SQLError> {
        let Some((array, indices)) = args.split_first() else {
            return Err(SQLError::Internal("array access has no operand".into()));
        };
        if indices.is_empty()
            || (dispatch == FunctionDispatch::ArraySlices && !indices.len().is_multiple_of(2))
        {
            return Err(SQLError::Internal("invalid array access bounds".into()));
        }
        let array_sql = self.expression(array, scope, subqueries)?;
        let mut rendered = if matches!(
            array,
            ScalarExpr::Column(_) | ScalarExpr::QualifiedColumn { .. } | ScalarExpr::Position(_)
        ) {
            array_sql
        } else {
            // Nested accesses need their own parentheses to preserve their dimensional grouping.
            format!("({array_sql})")
        };
        if dispatch == FunctionDispatch::ArraySlices {
            for bounds in indices.chunks_exact(2) {
                let lower = self.slice_bound(&bounds[0], scope, subqueries)?;
                let upper = self.slice_bound(&bounds[1], scope, subqueries)?;
                write!(rendered, "[{lower}:{upper}]").expect("writing to a String cannot fail");
            }
        } else {
            for index in indices {
                write!(rendered, "[{}]", self.expression(index, scope, subqueries)?)
                    .expect("writing to a String cannot fail");
            }
        }
        Ok(rendered)
    }

    fn slice_bound(
        &self,
        bound: &ScalarExpr,
        scope: &Scope,
        subqueries: &[QueryPlan],
    ) -> Result<String, SQLError> {
        if matches!(bound, ScalarExpr::Literal(Value::Null)) {
            Ok(String::new())
        } else {
            self.expression(bound, scope, subqueries)
        }
    }
}

#[cfg(test)]
mod tests {
    use crate::catalog::{
        projection::helpers::index_definitions::index_key_definition, test_support::empty_catalog,
        RelationLookupMode, RelationNameResolution,
    };

    #[test]
    fn stored_array_keys_follow_postgresql_subscript_and_slice_syntax() {
        let catalog = empty_catalog();
        let resolution = RelationNameResolution {
            search_path: vec!["public".into()],
            temporary_schema: "pg_temp_1".into(),
            temporary_namespace_allocated: false,
            current_user: "uqa".into(),
            lookup_mode: RelationLookupMode::Dynamic,
        };
        // PostgreSQL 18 pg_get_indexdef(index, 1, pretty) supplies both output forms.
        for (input, expected, pretty_expected) in [
            ("value[2]", "(value[2])", "(value[2])"),
            ("value[1][2]", "(value[1][2])", "(value[1][2])"),
            ("value[1:2]", "(value[1:2])", "(value[1:2])"),
            ("value[:][2]", "(value[:][1:2])", "(value[:][1:2])"),
            ("value[2:]", "(value[2:])", "(value[2:])"),
            ("(value[1:2])[2]", "((value[1:2])[2])", "((value[1:2])[2])"),
            (
                "(ARRAY[1,2])[1]",
                "((ARRAY[1, 2])[1])",
                "((ARRAY[1, 2])[1])",
            ),
            (
                "(value || value)[2]",
                "(((value || value))[2])",
                "((value || value)[2])",
            ),
            ("value[1] % 2", "((value[1] % 2))", "(value[1] % 2)"),
            (
                "subscript(value, 2)",
                "subscript(value, 2)",
                "subscript(value, 2)",
            ),
            (
                "slice(value, 1, 2)",
                "slice(value, 1, 2)",
                "slice(value, 1, 2)",
            ),
        ] {
            let uqa_sql::Statement::CreateIndex(index) =
                uqa_sql::compile(&format!("CREATE INDEX probe ON items (({input}))"))
                    .unwrap()
                    .remove(0)
            else {
                panic!("expected index");
            };
            for (pretty, expected) in [(false, expected), (true, pretty_expected)] {
                assert_eq!(
                    index_key_definition(&catalog, &resolution, &index.columns[0], pretty).unwrap(),
                    expected,
                    "{input}, pretty={pretty}",
                );
            }
        }
    }
}