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::{ColumnDesc, Field, IndexId, Schema};
22use risingwave_common::session_config::SessionConfig;
23use risingwave_common::util::epoch::Epoch;
24use risingwave_common::util::sort_util::ColumnOrder;
25use risingwave_pb::catalog::{
26    PbIndex, PbIndexColumnProperties, PbVectorIndexInfo, vector_index_info,
27};
28
29use crate::catalog::table_catalog::TableType;
30use crate::catalog::{OwnedByUserCatalog, TableCatalog};
31use crate::expr::{ExprDisplay, ExprImpl, ExprRewriter as _, FunctionCall};
32use crate::user::UserId;
33
34#[derive(Clone, Debug, Educe)]
35#[educe(PartialEq, Eq, Hash)]
36pub struct TableIndex {
37    pub name: String,
38    /// The properties of the index columns.
39    /// <https://www.postgresql.org/docs/current/functions-info.html#FUNCTIONS-INFO-INDEX-COLUMN-PROPS>
40    pub index_column_properties: Vec<PbIndexColumnProperties>,
41
42    pub index_table: Arc<TableCatalog>,
43
44    pub primary_table: Arc<TableCatalog>,
45
46    pub primary_to_secondary_mapping: BTreeMap<usize, usize>,
47
48    pub secondary_to_primary_mapping: BTreeMap<usize, usize>,
49
50    /// Map function call from the primary table to the index table.
51    /// Use `HashMap` instead of `BTreeMap`, because `FunctionCall` can't be used as the key for
52    /// `BTreeMap`. BTW, the trait `std::hash::Hash` is not implemented for
53    /// `HashMap<function_call::FunctionCall, usize>`, so we need to ignore it. It will not
54    /// affect the correctness, since it can be derived by `index_item`.
55    #[educe(PartialEq(ignore))]
56    #[educe(Hash(ignore))]
57    pub function_mapping: HashMap<FunctionCall, usize>,
58
59    pub index_columns_len: u32,
60}
61
62#[derive(Clone, Debug, PartialEq, Eq, Educe)]
63#[educe(Hash)]
64pub struct VectorIndex {
65    pub index_table: Arc<TableCatalog>,
66    pub vector_expr: ExprImpl,
67    #[educe(Hash(ignore))]
68    pub primary_to_included_info_column_mapping: HashMap<usize, usize>,
69    pub primary_key_idx_in_info_columns: Vec<usize>,
70    pub included_info_columns: Vec<usize>,
71    pub vector_index_info: PbVectorIndexInfo,
72}
73
74impl VectorIndex {
75    pub fn info_column_desc(&self) -> Vec<ColumnDesc> {
76        self.index_table.columns[1..=self.included_info_columns.len()]
77            .iter()
78            .map(|col| col.column_desc.clone())
79            .collect()
80    }
81
82    pub fn resolve_hnsw_ef_search(&self, config: &SessionConfig) -> Option<usize> {
83        match self.vector_index_info.config.as_ref().unwrap() {
84            vector_index_info::Config::Flat(_) => None,
85            vector_index_info::Config::HnswFlat(_) => Some(config.batch_hnsw_ef_search()),
86        }
87    }
88}
89
90#[derive(Clone, Debug, Hash, PartialEq, Eq)]
91pub enum IndexType {
92    Table(Arc<TableIndex>),
93    Vector(Arc<VectorIndex>),
94}
95
96#[derive(Clone, Debug, Hash, PartialEq, Eq)]
97pub struct IndexCatalog {
98    pub id: IndexId,
99
100    pub name: String,
101
102    /// Only `InputRef` and `FuncCall` type index is supported Now.
103    /// The index of `InputRef` is the column index of the primary table.
104    /// The `index_item` size is equal to the index table columns size
105    /// The input args of `FuncCall` is also the column index of the primary table.
106    pub index_item: Vec<ExprImpl>,
107
108    pub index_type: IndexType,
109
110    pub primary_table: Arc<TableCatalog>,
111
112    pub created_at_epoch: Option<Epoch>,
113
114    pub initialized_at_epoch: Option<Epoch>,
115
116    pub created_at_cluster_version: Option<String>,
117
118    pub initialized_at_cluster_version: Option<String>,
119}
120
121impl IndexCatalog {
122    pub fn build_from(
123        index_prost: &PbIndex,
124        index_table: &Arc<TableCatalog>,
125        primary_table: &Arc<TableCatalog>,
126    ) -> Self {
127        let index_item: Vec<ExprImpl> = index_prost
128            .index_item
129            .iter()
130            .map(|expr| ExprImpl::from_expr_proto(expr).unwrap())
131            .map(|expr| item_rewriter::CompositeCastEliminator.rewrite_expr(expr))
132            .collect();
133
134        let index_type = match index_table.table_type {
135            TableType::Index => {
136                let primary_to_secondary_mapping: BTreeMap<usize, usize> = index_item
137                    .iter()
138                    .enumerate()
139                    .filter_map(|(i, expr)| match expr {
140                        ExprImpl::InputRef(input_ref) => Some((input_ref.index, i)),
141                        ExprImpl::FunctionCall(_) => None,
142                        _ => unreachable!(),
143                    })
144                    .collect();
145
146                let secondary_to_primary_mapping = BTreeMap::from_iter(
147                    primary_to_secondary_mapping
148                        .clone()
149                        .into_iter()
150                        .map(|(x, y)| (y, x)),
151                );
152
153                let function_mapping: HashMap<FunctionCall, usize> = index_item
154                    .iter()
155                    .enumerate()
156                    .filter_map(|(i, expr)| match expr {
157                        ExprImpl::InputRef(_) => None,
158                        ExprImpl::FunctionCall(func) => Some((func.deref().clone(), i)),
159                        _ => unreachable!(),
160                    })
161                    .collect();
162                IndexType::Table(Arc::new(TableIndex {
163                    name: index_prost.name.clone(),
164                    index_column_properties: index_prost.index_column_properties.clone(),
165                    index_columns_len: index_prost.index_columns_len,
166                    index_table: index_table.clone(),
167                    primary_table: primary_table.clone(),
168                    primary_to_secondary_mapping,
169                    secondary_to_primary_mapping,
170                    function_mapping,
171                }))
172            }
173            TableType::VectorIndex => {
174                assert_eq!(index_prost.index_columns_len, 1);
175                let included_info_columns = index_item[1..].iter().map(|item| {
176                    let ExprImpl::InputRef(input) = item else {
177                        panic!("vector index included columns must be from direct input column, but got: {:?}", item);
178                    };
179                    input.index
180                }).collect_vec();
181                let primary_to_included_info_column_mapping: HashMap<_, _> = included_info_columns
182                    .iter()
183                    .enumerate()
184                    .map(|(included_info_column_idx, primary_column_idx)| {
185                        (*primary_column_idx, included_info_column_idx)
186                    })
187                    .collect();
188                let primary_key_idx_in_info_columns = primary_table
189                    .pk()
190                    .iter()
191                    .map(|order| primary_to_included_info_column_mapping[&order.column_index])
192                    .collect();
193                IndexType::Vector(Arc::new(VectorIndex {
194                    index_table: index_table.clone(),
195                    vector_expr: index_item[0].clone(),
196                    primary_to_included_info_column_mapping,
197                    primary_key_idx_in_info_columns,
198                    included_info_columns,
199                    vector_index_info: index_table
200                        .vector_index_info
201                        .expect("should exist for vector index"),
202                }))
203            }
204            TableType::Table | TableType::MaterializedView | TableType::Internal => {
205                unreachable!()
206            }
207        };
208
209        IndexCatalog {
210            id: index_prost.id,
211            name: index_prost.name.clone(),
212            index_item,
213            index_type,
214            primary_table: primary_table.clone(),
215            created_at_epoch: index_prost.created_at_epoch.map(Epoch::from),
216            initialized_at_epoch: index_prost.initialized_at_epoch.map(Epoch::from),
217            created_at_cluster_version: index_prost.created_at_cluster_version.clone(),
218            initialized_at_cluster_version: index_prost.initialized_at_cluster_version.clone(),
219        }
220    }
221}
222
223impl TableIndex {
224    pub fn primary_table_pk_ref_to_index_table(&self) -> Vec<ColumnOrder> {
225        let mapping = self.primary_to_secondary_mapping();
226
227        self.primary_table
228            .pk
229            .iter()
230            .map(|x| ColumnOrder::new(*mapping.get(&x.column_index).unwrap(), x.order_type))
231            .collect_vec()
232    }
233
234    pub fn primary_table_distribute_key_ref_to_index_table(&self) -> Vec<usize> {
235        let mapping = self.primary_to_secondary_mapping();
236
237        self.primary_table
238            .distribution_key
239            .iter()
240            .map(|x| *mapping.get(x).unwrap())
241            .collect_vec()
242    }
243
244    pub fn full_covering(&self) -> bool {
245        self.index_table.columns.len() == self.primary_table.columns.len()
246    }
247
248    /// A mapping maps the column index of the secondary index to the column index of the primary
249    /// table.
250    pub fn secondary_to_primary_mapping(&self) -> &BTreeMap<usize, usize> {
251        &self.secondary_to_primary_mapping
252    }
253
254    /// A mapping maps the column index of the primary table to the column index of the secondary
255    /// index.
256    pub fn primary_to_secondary_mapping(&self) -> &BTreeMap<usize, usize> {
257        &self.primary_to_secondary_mapping
258    }
259
260    pub fn function_mapping(&self) -> &HashMap<FunctionCall, usize> {
261        &self.function_mapping
262    }
263}
264
265impl IndexCatalog {
266    pub fn index_table(&self) -> &Arc<TableCatalog> {
267        match &self.index_type {
268            IndexType::Table(index) => &index.index_table,
269            IndexType::Vector(index) => &index.index_table,
270        }
271    }
272
273    /// Get the column properties of the index column.
274    pub fn get_column_properties(&self, column_idx: usize) -> Option<PbIndexColumnProperties> {
275        match &self.index_type {
276            IndexType::Table(index) => index.index_column_properties.get(column_idx).cloned(),
277            IndexType::Vector { .. } => {
278                if column_idx == 0 {
279                    // return with the default value defined in [https://www.postgresql.org/docs/current/sql-createindex.html]
280                    Some(PbIndexColumnProperties {
281                        is_desc: false,
282                        nulls_first: false,
283                    })
284                } else {
285                    None
286                }
287            }
288        }
289    }
290
291    pub fn get_column_def(&self, column_idx: usize) -> Option<String> {
292        if let Some(col) = self.index_table().columns.get(column_idx) {
293            if col.is_hidden {
294                return None;
295            }
296        } else {
297            return None;
298        }
299        let expr_display = ExprDisplay {
300            expr: &self.index_item[column_idx],
301            input_schema: &Schema::new(
302                self.primary_table
303                    .columns
304                    .iter()
305                    .map(|col| Field::from(&col.column_desc))
306                    .collect_vec(),
307            ),
308        };
309
310        // TODO(Kexiang): Currently, extra info like ":Int32" introduced by `ExprDisplay` is kept for simplity.
311        // We'd better remove it in the future.
312        Some(expr_display.to_string())
313    }
314
315    pub fn display(&self) -> IndexDisplay {
316        let index_table = self.index_table().clone();
317        let index_columns_with_ordering = index_table
318            .pk
319            .iter()
320            .filter(|x| !index_table.columns[x.column_index].is_hidden)
321            .map(|x| {
322                let index_column_name = index_table.columns[x.column_index].name().to_owned();
323                format!("{} {}", index_column_name, x.order_type)
324            })
325            .collect_vec();
326
327        let pk_column_index_set = index_table
328            .pk
329            .iter()
330            .map(|x| x.column_index)
331            .collect::<HashSet<_>>();
332
333        let include_columns = index_table
334            .columns
335            .iter()
336            .enumerate()
337            .filter(|(i, _)| !pk_column_index_set.contains(i))
338            .filter(|(_, x)| !x.is_hidden)
339            .map(|(_, x)| x.name().to_owned())
340            .collect_vec();
341
342        let distributed_by_columns = index_table
343            .distribution_key
344            .iter()
345            .map(|&x| index_table.columns[x].name().to_owned())
346            .collect_vec();
347
348        IndexDisplay {
349            index_columns_with_ordering,
350            include_columns,
351            distributed_by_columns,
352        }
353    }
354
355    pub fn is_created(&self) -> bool {
356        self.index_table().is_created()
357    }
358}
359
360pub struct IndexDisplay {
361    pub index_columns_with_ordering: Vec<String>,
362    pub include_columns: Vec<String>,
363    pub distributed_by_columns: Vec<String>,
364}
365
366impl OwnedByUserCatalog for IndexCatalog {
367    fn owner(&self) -> UserId {
368        self.index_table().owner
369    }
370}
371
372mod item_rewriter {
373    use risingwave_pb::expr::expr_node;
374
375    use crate::expr::{Expr, ExprImpl, ExprRewriter, FunctionCall};
376
377    /// Rewrite the expression of index item to eliminate `CompositeCast`, if any. This is needed
378    /// if the type of a column was changed and there's functional index on it.
379    ///
380    /// # Example
381    ///
382    /// Imagine there's a table created with `CREATE TABLE t (v struct<a int, b int>)`.
383    /// Then we create an index on it with `CREATE INDEX idx ON t ((v).a)`, which will create an
384    /// index item `Field(InputRef(0), 0)`.
385    ///
386    /// If we alter the column with `ALTER TABLE t ALTER COLUMN v TYPE struct<x varchar, a int>`,
387    /// the meta service will wrap the `InputRef(0)` with a `CompositeCast` to maintain the correct
388    /// return type. The index item will now become `Field(CompositeCast(InputRef(0)), 0)`.
389    ///
390    /// `CompositeCast` is for internal use only, and cannot be constructed or executed. To allow
391    /// this functional index to work and be matched with user queries, we need to eliminate it
392    /// here. By comparing the input and output types of `CompositeCast` and matching the field id,
393    /// we can find the real `Field` index and rewrite it to `Field(InputRef(0), 1)`.
394    ///
395    /// Note that if the field is dropped, we will leave the index item as is. This makes the index
396    /// item invalid, and it will never be matched and used.
397    pub struct CompositeCastEliminator;
398
399    impl ExprRewriter for CompositeCastEliminator {
400        fn rewrite_function_call(&mut self, func_call: FunctionCall) -> ExprImpl {
401            let (func_type, inputs, ret) = func_call.decompose();
402
403            // Flatten consecutive `CompositeCast`.
404            if func_type == expr_node::Type::CompositeCast {
405                let child = inputs[0].clone();
406
407                if let Some(child) = child.as_function_call()
408                    && child.func_type() == expr_node::Type::CompositeCast
409                {
410                    let new_child = child.inputs()[0].clone();
411
412                    // If the type already matches, no need to wrap again.
413                    // Recursively eliminate more composite cast by calling rewrite again.
414                    if new_child.return_type() == ret {
415                        return self.rewrite_expr(new_child);
416                    } else {
417                        let new_composite_cast =
418                            FunctionCall::new_unchecked(func_type, vec![new_child], ret);
419                        return self.rewrite_function_call(new_composite_cast);
420                    }
421                }
422            }
423            // Rewrite `Field(CompositeCast(x), y)` to `Field(x, y')`.
424            // TODO: also support rewriting `ArrayAccess` and `MapAccess`.
425            else if func_type == expr_node::Type::Field {
426                let child = inputs[0].clone();
427
428                if let Some(child) = child.as_function_call()
429                    && child.func_type() == expr_node::Type::CompositeCast
430                {
431                    let index = (inputs[1].clone().into_literal().unwrap())
432                        .get_data()
433                        .clone()
434                        .unwrap()
435                        .into_int32();
436
437                    let struct_type = child.return_type().into_struct();
438                    let field_id = struct_type
439                        .id_at(index as usize)
440                        .expect("ids should be set");
441
442                    // Unwrap the composite cast.
443                    let new_child = child.inputs()[0].clone();
444                    let new_struct_type = new_child.return_type().into_struct();
445
446                    let Some(new_index) = new_struct_type
447                        .ids()
448                        .expect("ids should be set")
449                        .position(|x| x == field_id)
450                    else {
451                        // Previously we have index on this field, but now it's dropped.
452                        // As a result, this entire index item becomes invalid.
453                        // Simply leave it as is. Users cannot construct a `CompositeCast` (which is
454                        // not user-facing), thus this index item will never be matched and used.
455                        return FunctionCall::new_unchecked(func_type, inputs, ret).into();
456                    };
457                    let new_index = ExprImpl::literal_int(new_index as i32);
458
459                    let new_inputs = vec![new_child, new_index];
460                    let new_field_call = FunctionCall::new_unchecked(func_type, new_inputs, ret);
461
462                    // Recursively eliminate more composite cast by calling rewrite again.
463                    return self.rewrite_function_call(new_field_call);
464                }
465            }
466
467            let inputs = inputs
468                .into_iter()
469                .map(|expr| self.rewrite_expr(expr))
470                .collect();
471            FunctionCall::new_unchecked(func_type, inputs, ret).into()
472        }
473    }
474}
risingwave_frontend/catalog/index_catalog.rs

risingwave_frontend/catalog/
index_catalog.rs
