perf(migration): replace N+1 updates in AclTimestampBackfill with grouped IN-clause batches

Assisted-by: Claude Code:claude-sonnet-4-6
Signed-off-by: Andy Scherzinger <info@andy-scherzinger.de>

Author: Andy Scherzinger

lib/Migration/AclTimestampBackfill.php

@@ -40,20 +40,27 @@ public function run(IOutput $output): void {
 			return;
 		}
 
-		$updateQb = $this->db->getQueryBuilder();
-		$updateQb->update('deck_board_acl')
-			->set('created_at', $updateQb->createParameter('ts'))
-			->set('last_modified_at', $updateQb->createParameter('ts'))
-			->where($updateQb->expr()->eq('id', $updateQb->createParameter('acl_id')));
-
+		// Group ACL IDs by target timestamp to issue one UPDATE per group
+		// rather than one UPDATE per row (avoids N+1 queries).
 		$now = time();
-		$updated = 0;
+		$groups = [];
 		foreach ($rows as $row) {
 			$timestamp = ((int)$row['board_last_modified'] > 0) ? (int)$row['board_last_modified'] : $now;
-			$updateQb->setParameter('ts', $timestamp, IQueryBuilder::PARAM_INT);
-			$updateQb->setParameter('acl_id', (int)$row['acl_id'], IQueryBuilder::PARAM_INT);
-			$updateQb->executeStatement();
-			$updated++;
+			$groups[$timestamp][] = (int)$row['acl_id'];
+		}
+
+		$updated = 0;
+		foreach ($groups as $timestamp => $ids) {
+			// Chunk at 1000 for Oracle compatibility (same limit used by chunkQuery).
+			foreach (array_chunk($ids, 1000) as $chunk) {
+				$updateQb = $this->db->getQueryBuilder();
+				$updateQb->update('deck_board_acl')
+					->set('created_at', $updateQb->createNamedParameter($timestamp, IQueryBuilder::PARAM_INT))
+					->set('last_modified_at', $updateQb->createNamedParameter($timestamp, IQueryBuilder::PARAM_INT))
+					->where($updateQb->expr()->in('id', $updateQb->createNamedParameter($chunk, IQueryBuilder::PARAM_INT_ARRAY)));
+				$updateQb->executeStatement();
+				$updated += count($chunk);
+			}
 		}
 
 		$output->info('AclTimestampBackfill: updated ' . $updated . ' row(s)');

tests/unit/Migration/AclTimestampBackfillTest.php

@@ -45,15 +45,16 @@ public function testRunNoRowsIsNoop(): void {
 		$this->backfill->run($this->output);
 	}
 
-	public function testRunUpdatesTwoRows(): void {
+	public function testRunGroupsRowsWithSameTimestampIntoOneUpdate(): void {
+		// Two ACLs from the same board share the same timestamp → only 1 UPDATE
 		$rows = [
 			['acl_id' => 1, 'board_last_modified' => 1000000],
-			['acl_id' => 2, 'board_last_modified' => 2000000],
+			['acl_id' => 2, 'board_last_modified' => 1000000],
 		];
 		[$selectQb] = $this->buildSelectQb($rows);
-		$updateQb = $this->buildUpdateQb(2);
+		$updateQb = $this->buildUpdateQb(1); // single IN-clause UPDATE for both IDs
 
-		$this->db->expects($this->exactly(2))
+		$this->db->expects($this->exactly(2)) // 1 SELECT + 1 UPDATE
 			->method('getQueryBuilder')
 			->willReturnOnConsecutiveCalls($selectQb, $updateQb);
 
@@ -64,13 +65,34 @@ public function testRunUpdatesTwoRows(): void {
 		$this->backfill->run($this->output);
 	}
 
+	public function testRunIssuesSeparateUpdatePerDistinctTimestamp(): void {
+		// Two ACLs from different boards → two distinct timestamps → 2 UPDATEs
+		$rows = [
+			['acl_id' => 1, 'board_last_modified' => 1000000],
+			['acl_id' => 2, 'board_last_modified' => 2000000],
+		];
+		[$selectQb] = $this->buildSelectQb($rows);
+		$updateQb1 = $this->buildUpdateQb(1);
+		$updateQb2 = $this->buildUpdateQb(1);
+
+		$this->db->expects($this->exactly(3)) // 1 SELECT + 2 UPDATEs
+			->method('getQueryBuilder')
+			->willReturnOnConsecutiveCalls($selectQb, $updateQb1, $updateQb2);
+
+		$this->output->expects($this->once())
+			->method('info')
+			->with($this->stringContains('2'));
+
+		$this->backfill->run($this->output);
+	}
+
 	public function testRunUsesBoardTimestampWhenAvailable(): void {
 		$rows = [['acl_id' => 1, 'board_last_modified' => 1234567]];
 		[$selectQb] = $this->buildSelectQb($rows);
 
 		$capturedTs = null;
-		$updateQb = $this->buildUpdateQb(1, function (string $name, mixed $value) use (&$capturedTs): void {
-			if ($name === 'ts') {
+		$updateQb = $this->buildUpdateQb(1, function (mixed $value, int $type) use (&$capturedTs): void {
+			if ($type === IQueryBuilder::PARAM_INT) {
 				$capturedTs = $value;
 			}
 		});
@@ -91,8 +113,8 @@ public function testRunUsesCurrentTimeWhenBoardTimestampIsZero(): void {
 
 		$capturedTs = null;
 		$before = time();
-		$updateQb = $this->buildUpdateQb(1, function (string $name, mixed $value) use (&$capturedTs): void {
-			if ($name === 'ts') {
+		$updateQb = $this->buildUpdateQb(1, function (mixed $value, int $type) use (&$capturedTs): void {
+			if ($type === IQueryBuilder::PARAM_INT) {
 				$capturedTs = $value;
 			}
 		});
@@ -132,25 +154,26 @@ private function buildSelectQb(array $rows): array {
 		return [$qb];
 	}
 
-	private function buildUpdateQb(int $expectedExecutions, ?\Closure $onSetParameter = null): IQueryBuilder&MockObject {
+	private function buildUpdateQb(int $expectedExecutions, ?\Closure $onCreateNamedParameter = null): IQueryBuilder&MockObject {
 		$expr = $this->createMock(IExpressionBuilder::class);
-		$expr->method('eq')->willReturn('1=1');
+		$expr->method('in')->willReturn('1=1');
 
 		$qb = $this->createMock(IQueryBuilder::class);
 		$qb->method('update')->willReturnSelf();
 		$qb->method('set')->willReturnSelf();
 		$qb->method('where')->willReturnSelf();
-		$qb->method('createParameter')->willReturn('?');
 		$qb->method('expr')->willReturn($expr);
 		$qb->expects($this->exactly($expectedExecutions))->method('executeStatement');
 
-		if ($onSetParameter !== null) {
-			$qb->method('setParameter')->willReturnCallback(function (string $name, mixed $value) use ($onSetParameter, $qb) {
-				$onSetParameter($name, $value);
-				return $qb;
-			});
+		if ($onCreateNamedParameter !== null) {
+			$qb->method('createNamedParameter')->willReturnCallback(
+				function (mixed $value, int $type) use ($onCreateNamedParameter): string {
+					$onCreateNamedParameter($value, $type);
+					return '?';
+				}
+			);
 		} else {
-			$qb->method('setParameter')->willReturnSelf();
+			$qb->method('createNamedParameter')->willReturn('?');
 		}
 
 		return $qb;