risingwave_frontend/catalog/
index_catalog.rs

1// Copyright 2025 RisingWave Labs
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15use std::collections::{BTreeMap, HashMap, HashSet};
16use std::ops::Deref;
17use std::sync::Arc;
18
19use educe::Educe;
20use itertools::Itertools;
21use risingwave_common::catalog::{Field, IndexId, Schema};
22use risingwave_common::util::epoch::Epoch;
23use risingwave_common::util::sort_util::ColumnOrder;
24use risingwave_pb::catalog::{PbIndex, PbIndexColumnProperties, PbVectorIndexInfo};
25
26use crate::catalog::table_catalog::TableType;
27use crate::catalog::{OwnedByUserCatalog, TableCatalog};
28use crate::expr::{ExprDisplay, ExprImpl, ExprRewriter as _, FunctionCall};
29use crate::user::UserId;
30
31#[derive(Clone, Debug, Educe)]
32#[educe(PartialEq, Eq, Hash)]
33pub struct TableIndex {
34    pub name: String,
35    /// The properties of the index columns.
36    /// <https://www.postgresql.org/docs/current/functions-info.html#FUNCTIONS-INFO-INDEX-COLUMN-PROPS>
37    pub index_column_properties: Vec<PbIndexColumnProperties>,
38
39    pub index_table: Arc<TableCatalog>,
40
41    pub primary_table: Arc<TableCatalog>,
42
43    pub primary_to_secondary_mapping: BTreeMap<usize, usize>,
44
45    pub secondary_to_primary_mapping: BTreeMap<usize, usize>,
46
47    /// Map function call from the primary table to the index table.
48    /// Use `HashMap` instead of `BTreeMap`, because `FunctionCall` can't be used as the key for
49    /// `BTreeMap`. BTW, the trait `std::hash::Hash` is not implemented for
50    /// `HashMap<function_call::FunctionCall, usize>`, so we need to ignore it. It will not
51    /// affect the correctness, since it can be derived by `index_item`.
52    #[educe(PartialEq(ignore))]
53    #[educe(Hash(ignore))]
54    pub function_mapping: HashMap<FunctionCall, usize>,
55
56    pub index_columns_len: u32,
57}
58
59#[derive(Clone, Debug, PartialEq, Eq, Educe)]
60#[educe(Hash)]
61pub struct VectorIndex {
62    pub index_table: Arc<TableCatalog>,
63    pub vector_expr: ExprImpl,
64    #[educe(Hash(ignore))]
65    pub primary_to_included_info_column_mapping: HashMap<usize, usize>,
66    pub primary_key_idx_in_info_columns: Vec<usize>,
67    pub included_info_columns: Vec<usize>,
68    pub vector_index_info: PbVectorIndexInfo,
69}
70
71#[derive(Clone, Debug, Hash, PartialEq, Eq)]
72pub enum IndexType {
73    Table(Arc<TableIndex>),
74    Vector(Arc<VectorIndex>),
75}
76
77#[derive(Clone, Debug, Hash, PartialEq, Eq)]
78pub struct IndexCatalog {
79    pub id: IndexId,
80
81    pub name: String,
82
83    /// Only `InputRef` and `FuncCall` type index is supported Now.
84    /// The index of `InputRef` is the column index of the primary table.
85    /// The `index_item` size is equal to the index table columns size
86    /// The input args of `FuncCall` is also the column index of the primary table.
87    pub index_item: Vec<ExprImpl>,
88
89    pub index_type: IndexType,
90
91    pub primary_table: Arc<TableCatalog>,
92
93    pub created_at_epoch: Option<Epoch>,
94
95    pub initialized_at_epoch: Option<Epoch>,
96
97    pub created_at_cluster_version: Option<String>,
98
99    pub initialized_at_cluster_version: Option<String>,
100}
101
102impl IndexCatalog {
103    pub fn build_from(
104        index_prost: &PbIndex,
105        index_table: &Arc<TableCatalog>,
106        primary_table: &Arc<TableCatalog>,
107    ) -> Self {
108        let index_item: Vec<ExprImpl> = index_prost
109            .index_item
110            .iter()
111            .map(|expr| ExprImpl::from_expr_proto(expr).unwrap())
112            .map(|expr| item_rewriter::CompositeCastEliminator.rewrite_expr(expr))
113            .collect();
114
115        let index_type = match index_table.table_type {
116            TableType::Index => {
117                let primary_to_secondary_mapping: BTreeMap<usize, usize> = index_item
118                    .iter()
119                    .enumerate()
120                    .filter_map(|(i, expr)| match expr {
121                        ExprImpl::InputRef(input_ref) => Some((input_ref.index, i)),
122                        ExprImpl::FunctionCall(_) => None,
123                        _ => unreachable!(),
124                    })
125                    .collect();
126
127                let secondary_to_primary_mapping = BTreeMap::from_iter(
128                    primary_to_secondary_mapping
129                        .clone()
130                        .into_iter()
131                        .map(|(x, y)| (y, x)),
132                );
133
134                let function_mapping: HashMap<FunctionCall, usize> = index_item
135                    .iter()
136                    .enumerate()
137                    .filter_map(|(i, expr)| match expr {
138                        ExprImpl::InputRef(_) => None,
139                        ExprImpl::FunctionCall(func) => Some((func.deref().clone(), i)),
140                        _ => unreachable!(),
141                    })
142                    .collect();
143                IndexType::Table(Arc::new(TableIndex {
144                    name: index_prost.name.clone(),
145                    index_column_properties: index_prost.index_column_properties.clone(),
146                    index_columns_len: index_prost.index_columns_len,
147                    index_table: index_table.clone(),
148                    primary_table: primary_table.clone(),
149                    primary_to_secondary_mapping,
150                    secondary_to_primary_mapping,
151                    function_mapping,
152                }))
153            }
154            TableType::VectorIndex => {
155                assert_eq!(index_prost.index_columns_len, 1);
156                let included_info_columns = index_item[1..].iter().map(|item| {
157                    let ExprImpl::InputRef(input) = item else {
158                        panic!("vector index included columns must be from direct input column, but got: {:?}", item);
159                    };
160                    input.index
161                }).collect_vec();
162                let primary_to_included_info_column_mapping: HashMap<_, _> = included_info_columns
163                    .iter()
164                    .enumerate()
165                    .map(|(included_info_column_idx, primary_column_idx)| {
166                        (*primary_column_idx, included_info_column_idx)
167                    })
168                    .collect();
169                let primary_key_idx_in_info_columns = primary_table
170                    .pk()
171                    .iter()
172                    .map(|order| primary_to_included_info_column_mapping[&order.column_index])
173                    .collect();
174                IndexType::Vector(Arc::new(VectorIndex {
175                    index_table: index_table.clone(),
176                    vector_expr: index_item[0].clone(),
177                    primary_to_included_info_column_mapping,
178                    primary_key_idx_in_info_columns,
179                    included_info_columns,
180                    vector_index_info: index_table
181                        .vector_index_info
182                        .expect("should exist for vector index"),
183                }))
184            }
185            TableType::Table | TableType::MaterializedView | TableType::Internal => {
186                unreachable!()
187            }
188        };
189
190        IndexCatalog {
191            id: index_prost.id.into(),
192            name: index_prost.name.clone(),
193            index_item,
194            index_type,
195            primary_table: primary_table.clone(),
196            created_at_epoch: index_prost.created_at_epoch.map(Epoch::from),
197            initialized_at_epoch: index_prost.initialized_at_epoch.map(Epoch::from),
198            created_at_cluster_version: index_prost.created_at_cluster_version.clone(),
199            initialized_at_cluster_version: index_prost.initialized_at_cluster_version.clone(),
200        }
201    }
202}
203
204impl TableIndex {
205    pub fn primary_table_pk_ref_to_index_table(&self) -> Vec<ColumnOrder> {
206        let mapping = self.primary_to_secondary_mapping();
207
208        self.primary_table
209            .pk
210            .iter()
211            .map(|x| ColumnOrder::new(*mapping.get(&x.column_index).unwrap(), x.order_type))
212            .collect_vec()
213    }
214
215    pub fn primary_table_distribute_key_ref_to_index_table(&self) -> Vec<usize> {
216        let mapping = self.primary_to_secondary_mapping();
217
218        self.primary_table
219            .distribution_key
220            .iter()
221            .map(|x| *mapping.get(x).unwrap())
222            .collect_vec()
223    }
224
225    pub fn full_covering(&self) -> bool {
226        self.index_table.columns.len() == self.primary_table.columns.len()
227    }
228
229    /// A mapping maps the column index of the secondary index to the column index of the primary
230    /// table.
231    pub fn secondary_to_primary_mapping(&self) -> &BTreeMap<usize, usize> {
232        &self.secondary_to_primary_mapping
233    }
234
235    /// A mapping maps the column index of the primary table to the column index of the secondary
236    /// index.
237    pub fn primary_to_secondary_mapping(&self) -> &BTreeMap<usize, usize> {
238        &self.primary_to_secondary_mapping
239    }
240
241    pub fn function_mapping(&self) -> &HashMap<FunctionCall, usize> {
242        &self.function_mapping
243    }
244}
245
246impl IndexCatalog {
247    pub fn index_table(&self) -> &Arc<TableCatalog> {
248        match &self.index_type {
249            IndexType::Table(index) => &index.index_table,
250            IndexType::Vector(index) => &index.index_table,
251        }
252    }
253
254    /// Get the column properties of the index column.
255    pub fn get_column_properties(&self, column_idx: usize) -> Option<PbIndexColumnProperties> {
256        match &self.index_type {
257            IndexType::Table(index) => index.index_column_properties.get(column_idx).cloned(),
258            IndexType::Vector { .. } => {
259                if column_idx == 0 {
260                    // return with the default value defined in [https://www.postgresql.org/docs/current/sql-createindex.html]
261                    Some(PbIndexColumnProperties {
262                        is_desc: false,
263                        nulls_first: false,
264                    })
265                } else {
266                    None
267                }
268            }
269        }
270    }
271
272    pub fn get_column_def(&self, column_idx: usize) -> Option<String> {
273        if let Some(col) = self.index_table().columns.get(column_idx) {
274            if col.is_hidden {
275                return None;
276            }
277        } else {
278            return None;
279        }
280        let expr_display = ExprDisplay {
281            expr: &self.index_item[column_idx],
282            input_schema: &Schema::new(
283                self.primary_table
284                    .columns
285                    .iter()
286                    .map(|col| Field::from(&col.column_desc))
287                    .collect_vec(),
288            ),
289        };
290
291        // TODO(Kexiang): Currently, extra info like ":Int32" introduced by `ExprDisplay` is kept for simplity.
292        // We'd better remove it in the future.
293        Some(expr_display.to_string())
294    }
295
296    pub fn display(&self) -> IndexDisplay {
297        let index_table = self.index_table().clone();
298        let index_columns_with_ordering = index_table
299            .pk
300            .iter()
301            .filter(|x| !index_table.columns[x.column_index].is_hidden)
302            .map(|x| {
303                let index_column_name = index_table.columns[x.column_index].name().to_owned();
304                format!("{} {}", index_column_name, x.order_type)
305            })
306            .collect_vec();
307
308        let pk_column_index_set = index_table
309            .pk
310            .iter()
311            .map(|x| x.column_index)
312            .collect::<HashSet<_>>();
313
314        let include_columns = index_table
315            .columns
316            .iter()
317            .enumerate()
318            .filter(|(i, _)| !pk_column_index_set.contains(i))
319            .filter(|(_, x)| !x.is_hidden)
320            .map(|(_, x)| x.name().to_owned())
321            .collect_vec();
322
323        let distributed_by_columns = index_table
324            .distribution_key
325            .iter()
326            .map(|&x| index_table.columns[x].name().to_owned())
327            .collect_vec();
328
329        IndexDisplay {
330            index_columns_with_ordering,
331            include_columns,
332            distributed_by_columns,
333        }
334    }
335
336    pub fn is_created(&self) -> bool {
337        self.index_table().is_created()
338    }
339}
340
341pub struct IndexDisplay {
342    pub index_columns_with_ordering: Vec<String>,
343    pub include_columns: Vec<String>,
344    pub distributed_by_columns: Vec<String>,
345}
346
347impl OwnedByUserCatalog for IndexCatalog {
348    fn owner(&self) -> UserId {
349        self.index_table().owner
350    }
351}
352
353mod item_rewriter {
354    use risingwave_pb::expr::expr_node;
355
356    use crate::expr::{Expr, ExprImpl, ExprRewriter, FunctionCall};
357
358    /// Rewrite the expression of index item to eliminate `CompositeCast`, if any. This is needed
359    /// if the type of a column was changed and there's functional index on it.
360    ///
361    /// # Example
362    ///
363    /// Imagine there's a table created with `CREATE TABLE t (v struct<a int, b int>)`.
364    /// Then we create an index on it with `CREATE INDEX idx ON t ((v).a)`, which will create an
365    /// index item `Field(InputRef(0), 0)`.
366    ///
367    /// If we alter the column with `ALTER TABLE t ALTER COLUMN v TYPE struct<x varchar, a int>`,
368    /// the meta service will wrap the `InputRef(0)` with a `CompositeCast` to maintain the correct
369    /// return type. The index item will now become `Field(CompositeCast(InputRef(0)), 0)`.
370    ///
371    /// `CompositeCast` is for internal use only, and cannot be constructed or executed. To allow
372    /// this functional index to work and be matched with user queries, we need to eliminate it
373    /// here. By comparing the input and output types of `CompositeCast` and matching the field id,
374    /// we can find the real `Field` index and rewrite it to `Field(InputRef(0), 1)`.
375    ///
376    /// Note that if the field is dropped, we will leave the index item as is. This makes the index
377    /// item invalid, and it will never be matched and used.
378    pub struct CompositeCastEliminator;
379
380    impl ExprRewriter for CompositeCastEliminator {
381        fn rewrite_function_call(&mut self, func_call: FunctionCall) -> ExprImpl {
382            let (func_type, inputs, ret) = func_call.decompose();
383
384            // Flatten consecutive `CompositeCast`.
385            if func_type == expr_node::Type::CompositeCast {
386                let child = inputs[0].clone();
387
388                if let Some(child) = child.as_function_call()
389                    && child.func_type() == expr_node::Type::CompositeCast
390                {
391                    let new_child = child.inputs()[0].clone();
392
393                    // If the type already matches, no need to wrap again.
394                    // Recursively eliminate more composite cast by calling rewrite again.
395                    if new_child.return_type() == ret {
396                        return self.rewrite_expr(new_child);
397                    } else {
398                        let new_composite_cast =
399                            FunctionCall::new_unchecked(func_type, vec![new_child], ret);
400                        return self.rewrite_function_call(new_composite_cast);
401                    }
402                }
403            }
404            // Rewrite `Field(CompositeCast(x), y)` to `Field(x, y')`.
405            // TODO: also support rewriting `ArrayAccess` and `MapAccess`.
406            else if func_type == expr_node::Type::Field {
407                let child = inputs[0].clone();
408
409                if let Some(child) = child.as_function_call()
410                    && child.func_type() == expr_node::Type::CompositeCast
411                {
412                    let index = (inputs[1].clone().into_literal().unwrap())
413                        .get_data()
414                        .clone()
415                        .unwrap()
416                        .into_int32();
417
418                    let struct_type = child.return_type().into_struct();
419                    let field_id = struct_type
420                        .id_at(index as usize)
421                        .expect("ids should be set");
422
423                    // Unwrap the composite cast.
424                    let new_child = child.inputs()[0].clone();
425                    let new_struct_type = new_child.return_type().into_struct();
426
427                    let Some(new_index) = new_struct_type
428                        .ids()
429                        .expect("ids should be set")
430                        .position(|x| x == field_id)
431                    else {
432                        // Previously we have index on this field, but now it's dropped.
433                        // As a result, this entire index item becomes invalid.
434                        // Simply leave it as is. Users cannot construct a `CompositeCast` (which is
435                        // not user-facing), thus this index item will never be matched and used.
436                        return FunctionCall::new_unchecked(func_type, inputs, ret).into();
437                    };
438                    let new_index = ExprImpl::literal_int(new_index as i32);
439
440                    let new_inputs = vec![new_child, new_index];
441                    let new_field_call = FunctionCall::new_unchecked(func_type, new_inputs, ret);
442
443                    // Recursively eliminate more composite cast by calling rewrite again.
444                    return self.rewrite_function_call(new_field_call);
445                }
446            }
447
448            let inputs = inputs
449                .into_iter()
450                .map(|expr| self.rewrite_expr(expr))
451                .collect();
452            FunctionCall::new_unchecked(func_type, inputs, ret).into()
453        }
454    }
455}
risingwave_frontend/catalog/index_catalog.rs

risingwave_frontend/catalog/
index_catalog.rs
