Statistics

$mysqli = new mysqli();
$res = $mysqli->query("SELECT 'abc'");
$res->fetch_assoc();
$res->close();

Every fetch operation will increase the value.

The statistic will not be increased if the result set is only buffered on the client, but not fetched, such as in the following example:

$mysqli = new mysqli();
$res = $mysqli->query("SELECT 'abc'");
$res->close();

This statistic is available as of PHP version 5.3.4.

• Faulty client application

• Client stopped reading after it found what it was looking for but has made MySQL calculate more records than needed

• Client application has stopped unexpectedly

• Faulty client application

• Client stopped reading after it found what it was looking for but has made MySQL calculate more records than needed

• Client application has stopped unexpectedly

• MYSQL_TYPE_NULL - proto_text_fetched_null

• MYSQL_TYPE_BIT - proto_text_fetched_bit

• MYSQL_TYPE_TINY - proto_text_fetched_tinyint

• MYSQL_TYPE_SHORT - proto_text_fetched_short

• MYSQL_TYPE_INT24 - proto_text_fetched_int24

• MYSQL_TYPE_LONG - proto_text_fetched_int

• MYSQL_TYPE_LONGLONG - proto_text_fetched_bigint

• MYSQL_TYPE_DECIMAL, MYSQL_TYPE_NEWDECIMAL - proto_text_fetched_decimal

• MYSQL_TYPE_FLOAT - proto_text_fetched_float

• MYSQL_TYPE_DOUBLE - proto_text_fetched_double

• MYSQL_TYPE_DATE, MYSQL_TYPE_NEWDATE - proto_text_fetched_date

• MYSQL_TYPE_YEAR - proto_text_fetched_year

• MYSQL_TYPE_TIME - proto_text_fetched_time

• MYSQL_TYPE_DATETIME - proto_text_fetched_datetime

• MYSQL_TYPE_TIMESTAMP - proto_text_fetched_timestamp

• MYSQL_TYPE_STRING, MYSQL_TYPE_VARSTRING, MYSQL_TYPE_VARCHAR - proto_text_fetched_string

• MYSQL_TYPE_TINY_BLOB, MYSQL_TYPE_MEDIUM_BLOB, MYSQL_TYPE_LONG_BLOB, MYSQL_TYPE_BLOB - proto_text_fetched_blob

• MYSQL_TYPE_ENUM - proto_text_fetched_enum

• MYSQL_TYPE_SET - proto_text_fetched_set

• MYSQL_TYPE_GEOMETRY - proto_text_fetched_geometry

• Any MYSQL_TYPE_* not listed before (there should be none) - proto_text_fetched_other

Note that the MYSQL_*-type constants may not be associated with the very same SQL column types in every version of MySQL.

• $link = new mysqli(...); $link->real_connect(...)

• unset($link)

• Persistent connection: pooled connection has been created with real_connect and there may be unknown options set - close implicitly to avoid returning a connection with unknown options

• Persistent connection: ping/change_user fails and ext/mysqli closes the connection

• end of script execution: close connections that have not been closed by the user

The statistics are incremented after checking the line and immediately before sending the corresponding MySQL client server protocol packet. If mysqlnd fails to send the packet over the wire the statistics will not be decremented. In case of a failure mysqlnd emits a PHP warning Error while sending %s packet. PID=%d.

Usage examples:

• Check if PHP sends certain commands to MySQL, for example, check if a client sends COM_PROCESS_KILL

• Calculate the average number of prepared statement executions by comparing COM_EXECUTE with COM_PREPARE

• Check if PHP has run any non-prepared SQL statements by checking if COM_QUERY is zero

• Identify PHP scripts that run an excessive number of SQL statements by checking COM_QUERY and COM_EXECUTE

mysqlnd allocates an internal command/network buffer of mysqlnd.net_cmd_buffer_size (php.ini) bytes for every connection. If a MySQL Client Server protocol command, for example, COM_QUERY (normal query), does not fit into the buffer, mysqlnd will grow the buffer to what is needed for sending the command. Whenever the buffer gets extended for one connection command_buffer_too_small will be incremented by one.

If mysqlnd has to grow the buffer beyond its initial size of mysqlnd.net_cmd_buffer_size (php.ini) bytes for almost every connection, you should consider to increase the default size to avoid re-allocations.

The default buffer size is 2048 bytes in PHP 5.3.0. In future versions the default will be 4kB or larger. The default can changed either through the php.ini setting mysqlnd.net_cmd_buffer_size or using mysqli_options(MYSQLI_OPT_NET_CMD_BUFFER_SIZE, int size).

It is recommended to set the buffer size to no less than 4096 bytes because mysqlnd also uses it when reading certain communication packet from MySQL. In PHP 5.3.0, mysqlnd will not grow the buffer if MySQL sends a packet that is larger than the current size of the buffer. As a consequence mysqlnd is unable to decode the packet and the client application will get an error. There are only two situations when the packet can be larger than the 2048 bytes default of mysqlnd.net_cmd_buffer_size in PHP 5.3.0: the packet transports a very long error message or the packet holds column meta data from COM_LIST_FIELD (mysql_list_fields()) and the meta data comes from a string column with a very long default value (>1900 bytes). No bug report on this exists - it should happen rarely.

As of PHP 5.3.2 mysqlnd does not allow setting buffers smaller than 4096 bytes.