At any point, grab the profiler using the adapter's
getProfiler() method:
<?php
$profiler = $db->getProfiler();
This returns a Zend_Db_Profiler object instance. With
that instance, the developer can examine your queries using a
variety of methods:
getTotalNumQueries()returns the total number of queries that have been profiled.getTotalElapsedSecs()returns the total number of seconds elapsed for all profiled queries.getQueryProfiles()returns an array of all query profiles.getLastQueryProfile()returns the last (most recent) query profile, regardless of whether or not the query has finished (if it hasn't, the end time will beNULL)clear()clears any past query profiles from the stack.
The return value of getLastQueryProfile() and the
individual elements of getQueryProfiles() are
Zend_Db_Profiler_Query objects, which provide the
ability to inspect the individual queries themselves:
getQuery()returns the SQL text of the query. The SQL text of a prepared statement with parameters is the text at the time the query was prepared, so it contains parameter placeholders, not the values used when the statement is executed.getQueryParams()returns an array of parameter values used when executing a prepared query. This includes both bound parameters and arguments to the statement'sexecute()method. The keys of the array are the positional (1-based) or named (string) parameter indices.getElapsedSecs()returns the number of seconds the query ran.
The information Zend_Db_Profiler provides is useful for
profiling bottlenecks in applications, and for debugging queries
that have been run. For instance, to see the exact query that was
last run:
<?php
$query = $profiler->getLastQueryProfile();
echo $query->getQuery();
Perhaps a page is generating slowly; use the profiler to determine first the total number of seconds of all queries, and then step through the queries to find the one that ran longest:
<?php
$totalTime = $profiler->getTotalElapsedSecs();
$queryCount = $profiler->getTotalNumQueries();
$longestTime = 0;
$longestQuery = null;
foreach ($profiler->getQueryProfiles() as $query) {
if ($query->getElapsedSecs() > $longestTime) {
$longestTime = $query->getElapsedSecs();
$longestQuery = $query->getQuery();
}
}
echo 'Executed ' . $queryCount . ' queries in ' . $totalTime .
' seconds' . "\n";
echo 'Average query length: ' . $totalTime / $queryCount .
' seconds' . "\n";
echo 'Queries per second: ' . $queryCount / $totalTime . "\n";
echo 'Longest query length: ' . $longestTime . "\n";
echo "Longest query: \n" . $longestQuery . "\n";