diff --git a/CHANGELOG.md b/CHANGELOG.md
index 63c341b1..0ab1cd13 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,8 @@
 
 ## 2.0.1 under development
 
-- Enh #477: Improve performance of `ArrayParser::parse()` method (@Tigrov)
+- Enh #477, #478: Improve performance of `ArrayParser::parse()` method (@Tigrov)
+- Enh #478: Improve performance of `StructuredParser::parse()` method (@Tigrov)
 
 ## 2.0.0 December 05, 2025
 
diff --git a/src/Data/ArrayParser.php b/src/Data/ArrayParser.php
index 1866ec0c..ac6e2bf9 100644
--- a/src/Data/ArrayParser.php
+++ b/src/Data/ArrayParser.php
@@ -6,7 +6,7 @@
 
 use function preg_match;
 use function strcspn;
-use function stripcslashes;
+use function stripslashes;
 use function strlen;
 use function substr;
 
@@ -71,7 +71,7 @@ private function parseQuotedString(string $value, int &$i): string
         preg_match('/(?>[^"\\\\]+|\\\\.)*/', $value, $matches, 0, $i + 1);
         $i += strlen($matches[0]) + 2;
 
-        return stripcslashes($matches[0]);
+        return stripslashes($matches[0]);
     }
 
     /**
diff --git a/src/Data/StructuredParser.php b/src/Data/StructuredParser.php
index 990faa27..ee74e9ad 100644
--- a/src/Data/StructuredParser.php
+++ b/src/Data/StructuredParser.php
@@ -4,7 +4,11 @@
 
 namespace Yiisoft\Db\Pgsql\Data;
 
-use function in_array;
+use function preg_match;
+use function strcspn;
+use function stripslashes;
+use function strlen;
+use function substr;
 
 /**
  * Structured type representation to PHP array parser for PostgreSQL Server.
@@ -58,16 +62,10 @@ private function parseComposite(string $value): array
      */
     private function parseQuotedString(string $value, int &$i): string
     {
-        for ($result = '', ++$i;; ++$i) {
-            if ($value[$i] === '\\') {
-                ++$i;
-            } elseif ($value[$i] === '"') {
-                ++$i;
-                return $result;
-            }
+        preg_match('/(?>[^"\\\\]+|\\\\.)*/', $value, $matches, 0, $i + 1);
+        $i += strlen($matches[0]) + 2;
 
-            $result .= $value[$i];
-        }
+        return stripslashes($matches[0]);
     }
 
     /**
@@ -75,12 +73,10 @@ private function parseQuotedString(string $value, int &$i): string
      */
     private function parseUnquotedString(string $value, int &$i): string
     {
-        for ($result = '';; ++$i) {
-            if (in_array($value[$i], [',', ')'], true)) {
-                return $result;
-            }
+        $length = strcspn($value, ',)', $i);
+        $result = substr($value, $i, $length);
+        $i += $length;
 
-            $result .= $value[$i];
-        }
+        return $result;
     }
 }
diff --git a/tests/StructuredParserTest.php b/tests/StructuredParserTest.php
index b9115af5..d240eab7 100644
--- a/tests/StructuredParserTest.php
+++ b/tests/StructuredParserTest.php
@@ -4,6 +4,7 @@
 
 namespace Yiisoft\Db\Pgsql\Tests;
 
+use PHPUnit\Framework\Attributes\DataProvider;
 use PHPUnit\Framework\TestCase;
 use Yiisoft\Db\Pgsql\Data\StructuredParser;
 
@@ -12,21 +13,44 @@
  */
 final class StructuredParserTest extends TestCase
 {
-    public function testParser(): void
+    public static function parserProvider(): iterable
     {
-        $parser = new StructuredParser();
-
-        $this->assertSame([null], $parser->parse('()'));
-        $this->assertSame([0 => null, 1 => null], $parser->parse('(,)'));
-        $this->assertSame([0 => '10.0', 1 => 'USD'], $parser->parse('(10.0,USD)'));
-        $this->assertSame([0 => '1', 1 => '-2', 2 => null, 3 => '42'], $parser->parse('(1,-2,,42)'));
-        $this->assertSame([0 => ''], $parser->parse('("")'));
-        $this->assertSame(
-            [0 => '[",","null",true,"false","f"]'],
-            $parser->parse('("[\",\",\"null\",true,\"false\",\"f\"]")'),
-        );
-
+        yield [[null], '()'];
+        yield [[''], '("")'];
+        yield [[null, null], '(,)'];
+        yield [
+            ["a\nb"],
+            "(\"a\nb\")",
+        ];
+        yield [
+            ['10.0', 'USD'],
+            '(10.0,USD)',
+        ];
+        yield [
+            ['1', '-2', null, '42'],
+            '(1,-2,,42)',
+        ];
+        yield [
+            [',', ')', '"', '\\', '"\\,)', 'NULL', 't', 'f'],
+            '(",",")","\\"","\\\\","\\"\\\\,)",NULL,t,f)',
+        ];
+        yield [
+            ['[",","null",true,"false","f"]'],
+            '("[\",\",\"null\",true,\"false\",\"f\"]")',
+        ];
+        // Multibyte strings
+        yield [
+            ['我', '👍🏻', 'multibyte строка我👍🏻', 'נטשופ צרכנות'],
+            '(我,👍🏻,"multibyte строка我👍🏻","נטשופ צרכנות")',
+        ];
         // Default values can have any expressions
-        $this->assertSame(null, $parser->parse("'(10.0,USD)::structured_type'"));
+        yield [null, "'(10.0,USD)::structured_type'"];
+    }
+
+    #[DataProvider('parserProvider')]
+    public function testParser(?array $expected, string $value): void
+    {
+        $parser = new StructuredParser();
+        $this->assertSame($expected, $parser->parse($value));
     }
 }