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[fix](inverted index) Fix empty string MATCH on keyword index returning wrong results #60500

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Merged
yiguolei merged 1 commit into from
Feb 5, 2026
+115 −15
Merged

[fix](inverted index) Fix empty string MATCH on keyword index returning wrong results #60500

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6 changes: 3 additions & 3 deletions be/src/olap/rowset/segment_v2/inverted_index/analyzer/analyzer.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -187,10 +187,10 @@ std::vector<TermInfo> InvertedIndexAnalyzer::get_analyse_result(
std::vector<TermInfo> InvertedIndexAnalyzer::get_analyse_result(
const std::string& search_str, const std::map<std::string, std::string>& properties) {
if (!should_analyzer(properties)) {
// Keyword index: all strings (including empty) are valid tokens for exact match.
// Empty string is a valid value in keyword index and should be matchable.
std::vector<TermInfo> result;
if (!search_str.empty()) {
result.emplace_back(search_str);
}
result.emplace_back(search_str);
return result;
}
InvertedIndexAnalyzerConfig config;
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7 changes: 3 additions & 4 deletions be/src/olap/rowset/segment_v2/inverted_index_reader.cpp
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Expand Up @@ -315,10 +315,9 @@ Status FullTextIndexReader::query(const IndexQueryContextPtr& context,
} else {
SCOPED_RAW_TIMER(&context->stats->inverted_index_analyzer_timer);
if (analyzer_ctx != nullptr && !analyzer_ctx->should_tokenize()) {
// Don't add empty string as token - empty query should match nothing
if (!search_str.empty()) {
query_info.term_infos.emplace_back(search_str);
}
// Keyword index: all strings (including empty) are valid tokens for exact match.
// Empty string is a valid value in keyword index and should be matchable.
query_info.term_infos.emplace_back(search_str);
} else if (analyzer_ctx != nullptr && analyzer_ctx->analyzer != nullptr) {
// Use analyzer from query context for consistent behavior across all segments.
// This ensures that the query uses the same analyzer settings (e.g., lowercase)
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13 changes: 5 additions & 8 deletions be/src/vec/functions/match.cpp
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Expand Up @@ -205,20 +205,17 @@ std::vector<TermInfo> FunctionMatchBase::analyse_query_str_token(
// - PARSER_NONE: no tokenization (keyword/exact match)
// - Other parsers: tokenize using the analyzer
if (!analyzer_ctx->should_tokenize()) {
// Keyword index or no tokenization needed
// Don't add empty string as token - empty query should match nothing
if (!match_query_str.empty()) {
query_tokens.emplace_back(match_query_str);
}
// Keyword index: all strings (including empty) are valid tokens for exact match.
// Empty string is a valid value in keyword index and should be matchable.
query_tokens.emplace_back(match_query_str);
return query_tokens;
}

// Safety check: if analyzer is nullptr but tokenization is expected, fall back to no tokenization
if (analyzer_ctx->analyzer == nullptr) {
VLOG_DEBUG << "Analyzer is nullptr, falling back to no tokenization";
if (!match_query_str.empty()) {
query_tokens.emplace_back(match_query_str);
}
// For fallback case, also allow empty strings to be matched
query_tokens.emplace_back(match_query_str);
return query_tokens;
}

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26 changes: 26 additions & 0 deletions regression-test/data/inverted_index_p0/test_empty_string_match.out
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@@ -0,0 +1,26 @@
-- This file is automatically generated. You should know what you did if you want to edit this
-- !keyword_index_path --
1
3

-- !keyword_slow_path --
1
3

-- !english_index_path --
0

-- !english_slow_path --
0

-- !keyword_nonempty --
2

-- !match_any_empty --
1
3

-- !match_all_empty --
1
3

78 changes: 78 additions & 0 deletions regression-test/suites/inverted_index_p0/test_empty_string_match.groovy
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@@ -0,0 +1,78 @@
// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements. See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership. The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License. You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the License for the
// specific language governing permissions and limitations
// under the License.

suite("test_empty_string_match", "p0") {
def tableName = "test_empty_string_match"

sql "DROP TABLE IF EXISTS ${tableName}"
sql """
CREATE TABLE ${tableName} (
id INT,
keyword_col TEXT DEFAULT '',
english_col TEXT DEFAULT '',
INDEX keyword_idx(keyword_col) USING INVERTED COMMENT 'keyword index',
INDEX english_idx(english_col) USING INVERTED PROPERTIES("parser" = "english") COMMENT 'english parser'
) ENGINE=OLAP
DUPLICATE KEY(id)
DISTRIBUTED BY HASH(id) BUCKETS 1
PROPERTIES("replication_allocation" = "tag.location.default: 1");
"""

sql """
INSERT INTO ${tableName} VALUES
(1, '', 'hello world'),
(2, 'test', ''),
(3, '', ''),
(4, 'data', 'some text');
"""

sql "SET enable_common_expr_pushdown = true"

// Test 1: Empty string match on keyword index (index path)
// Should match rows where keyword_col is empty string (rows 1 and 3)
sql "SET enable_inverted_index_query = true"
qt_keyword_index_path """SELECT id FROM ${tableName} WHERE keyword_col match '' ORDER BY id"""

// Test 2: Empty string match on keyword index (slow path)
// Should also match rows where keyword_col is empty string
sql "SET enable_inverted_index_query = false"
sql "SET enable_match_without_inverted_index = true"
qt_keyword_slow_path """SELECT id FROM ${tableName} WHERE keyword_col match '' ORDER BY id"""

// Test 3: Empty string match on tokenized index (index path)
// Should return no rows because empty string tokenizes to nothing
sql "SET enable_inverted_index_query = true"
qt_english_index_path """SELECT count() FROM ${tableName} WHERE english_col match ''"""

// Test 4: Empty string match on tokenized index (slow path)
// Should also return no rows
sql "SET enable_inverted_index_query = false"
qt_english_slow_path """SELECT count() FROM ${tableName} WHERE english_col match ''"""

// Test 5: Non-empty string match on keyword index should work as before
sql "SET enable_inverted_index_query = true"
qt_keyword_nonempty """SELECT id FROM ${tableName} WHERE keyword_col match 'test' ORDER BY id"""

// Test 6: Verify match_any with empty string on keyword index
sql "SET enable_inverted_index_query = false"
qt_match_any_empty """SELECT id FROM ${tableName} WHERE keyword_col match_any '' ORDER BY id"""

// Test 7: Verify match_all with empty string on keyword index
qt_match_all_empty """SELECT id FROM ${tableName} WHERE keyword_col match_all '' ORDER BY id"""

sql "DROP TABLE IF EXISTS ${tableName}"
}
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