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fix(database): drop the join-without-index rules #1255

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Merged
kesselb merged 1 commit into from
Oct 31, 2026
Merged

fix(database): drop the join-without-index rules #1255

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2 changes: 0 additions & 2 deletions lib/Database/Advisor.php
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Original file line number Diff line number Diff line change
Expand Up @@ -49,7 +49,6 @@ class Advisor {
'Aborted_connects',
'Thread_cache_hit_rate',
'Slow_query_ratio',
'Select_full_join',
'Sort_merge_passes',
'Created_tmp_disk_tables',
'Innodb_buffer_pool_hit_rate',
Expand All @@ -61,7 +60,6 @@ class Advisor {
'Slow_query_rate',
'Sort_rows',
'Sort_merge_passes_rate',
'Join_without_index_rate',
'Handler_read_first_rate',
'Handler_read_rnd_rate',
'Handler_read_rnd_next_rate',
Expand Down
29 changes: 0 additions & 29 deletions lib/Database/RuleSet/Mysql.php
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Expand Up @@ -177,20 +177,6 @@ private function build(): array {
requires: ['Slow_queries', 'Questions'],
);

$rules[] = new Rule(
id: 'Select_full_join',
name: 'Joins without indexes',
category: 'Performance',
severity: Rule::SEVERITY_WARNING,
formula: 'Select_full_join / Questions * 100',
test: 'value > 0.05',
issue: 'Some joins are scanning entire tables because no usable index exists on the join column.',
recommendation: 'Identify the offending queries (set log_queries_not_using_indexes) and add the missing indexes.',
justification: '%s%% of queries did a full join without an index.',
justificationFormula: 'value',
requires: ['Select_full_join', 'Questions'],
);

$rules[] = new Rule(
id: 'Sort_merge_passes',
name: 'Sort buffer passes',
Expand Down Expand Up @@ -488,21 +474,6 @@ private function build(): array {
);

// Performance / joins + scans (rate-based companions to existing absolute checks)
$rules[] = new Rule(
// upstream id: "Rate of joins without indexes"
id: 'Join_without_index_rate',
name: 'Join-without-index rate',
category: 'Performance',
severity: Rule::SEVERITY_NOTICE,
formula: '(Select_range_check + Select_scan + Select_full_join) / Uptime',
test: 'value * 60 * 60 > 1',
issue: 'Many SELECTs are doing full table scans or joins without indexes.',
recommendation: 'Add indexes for the columns used in JOIN conditions and WHERE filters.',
justification: 'Index-less join+scan rate: %s per hour; aim for less than 1.',
justificationFormula: 'round(value * 3600, 2)',
requires: ['Select_range_check', 'Select_scan', 'Select_full_join', 'Uptime'],
);

$rules[] = new Rule(
// upstream id: "Rate of reading first index entry"
id: 'Handler_read_first_rate',
Expand Down
16 changes: 0 additions & 16 deletions tests/lib/Database/AdvisorTest.php
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Expand Up @@ -11,7 +11,6 @@

use OCA\ServerInfo\Database\Advisor;
use OCA\ServerInfo\Database\ExpressionEvaluator;
use OCA\ServerInfo\Database\Rule;
use OCA\ServerInfo\Database\RuleResult;
use OCA\ServerInfo\Database\RuleSet\Mysql;
use OCA\ServerInfo\Database\Snapshot;
Expand Down Expand Up @@ -135,19 +134,4 @@ public function testReplicaLagPassesOnRunningReplica(): void {

$this->assertSame(RuleResult::STATUS_OK, $result->status);
}

/**
* Select_scan alone exceeds one per hour on any active Nextcloud, so the
* rule is a hint rather than a warning.
*/
public function testJoinWithoutIndexRateIsANotice(): void {
$result = $this->resultFor('Join_without_index_rate', [
'Select_range_check' => 0,
'Select_scan' => 50000,
'Select_full_join' => 0,
]);

$this->assertSame(RuleResult::STATUS_FAIL, $result->status);
$this->assertSame(Rule::SEVERITY_NOTICE, $result->rule->severity);
}
}
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