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In high concurrency environments, database performance often becomes a system bottleneck. As one of the mainstream languages for backend development, PHP widely uses mysqli extension to interact with MySQL. Among them, although the mysqli_stmt::attr_get function is not as common as prepare or execute , it can bring some help to performance tuning. This article will introduce in detail how to effectively optimize database operations in high concurrency scenarios in combination with the mysqli_stmt::attr_get function to improve the overall system response speed.
mysqli_stmt::attr_get is a method used in the PHP mysqli extension to get preprocessing statement properties. Prepared Statement is critical for high concurrency because it avoids SQL injection and reuses execution plans, reducing parsing costs.
The definition of this function is:
public int|bool mysqli_stmt::attr_get(int $attr)
Where $attr is the attribute identifier that needs to be obtained, and the function returns the value of the corresponding attribute.
Commonly used properties include:
MYSQLI_STMT_ATTR_UPDATE_MAX_LENGTH — Whether to automatically update the maximum field length
MYSQLI_STMT_ATTR_CURSOR_TYPE — Cursor type
Other internal settings for preprocessing statements
Understanding and obtaining these properties will help developers more accurately control SQL execution behavior and avoid unnecessary performance waste.
Under high concurrent requests, the overhead of database connections and preprocessing statements can lead to performance bottlenecks. The rational use of attr_get can allow the program to dynamically adjust the statement behavior or make decisions, avoiding repeated initialization and unnecessary parameter binding.
For example:
Determine the cursor type and decide whether to enable server-side cursors to avoid memory overflow caused by loading large data sets at one time.
Monitor the MYSQLI_STMT_ATTR_UPDATE_MAX_LENGTH attribute, dynamically adjust the field length cache, and improve network transmission efficiency.
When reusing preprocessing statements, ensure that the statement attributes are consistent and prevent errors from causing reconnection.
Here is a simple example showing how to get cursor type attributes and decide which data pull method to use:
$mysqli = new mysqli("m66.net", "user", "password", "database");
if ($mysqli->connect_errno) {
die("Connection failed: " . $mysqli->connect_error);
}
$stmt = $mysqli->prepare("SELECT id, name FROM users WHERE status = ?");
$status = 1;
$stmt->bind_param("i", $status);
$stmt->execute();
// Get cursor type attribute
$cursorType = $stmt->attr_get(MYSQLI_STMT_ATTR_CURSOR_TYPE);
if ($cursorType === MYSQLI_CURSOR_TYPE_READ_ONLY) {
// Server-side cursor，Can be pulled one by one，Suitable for large result sets
$stmt->store_result(); // Store result sets，Easy to access multiple times
while ($stmt->fetch()) {
// Processing data
}
} else {
// Ordinary cursor，Suitable for small result sets，All pull after processing
$result = $stmt->get_result();
while ($row = $result->fetch_assoc()) {
// Processing data
}
}
$stmt->close();
$mysqli->close();
By reading the properties of preprocessing statements, the program can dynamically judge the cursor behavior to avoid memory pressure caused by loading big data at one time.
Preprocessing statement multiplexing : By checking statement properties, avoiding repeated prepare operations and reducing database parsing time.
Set cursor types appropriately : Server-side cursors are suitable for large result sets, but increase connection burden; client-side cursors are suitable for small data volumes.
Turn on automatic update maximum length attribute : Ensure that the field length is dynamically adapted to avoid truncation or waste.
Batch execution and shard query : combine attribute judgment, reasonably shard, and reduce the pressure of single query.
Although mysqli_stmt::attr_get is not a core function that directly executes queries, in high concurrency scenarios, using it reasonably to dynamically adjust preprocessing statement attributes can effectively optimize database access strategies, reduce resource waste, and improve overall response speed.
Especially in complex business systems, monitoring and adjusting cursor type, maximum length and other attributes can avoid some difficult-to-observe performance risks, thereby ensuring the stable and efficient operation of the system.
For developers who want to deeply optimize the interactive performance of PHP and MySQL, mysqli_stmt::attr_get is one of the tools worthy of attention.
