boutell

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boutell

I'm going to examine a plausible, nontrivial query that comes up for client sites and
consider how it would be implemented in both MongoDB and a MySQL back end that attempts
to support a lot of the capabilities we like in MongoDB.

I'm not going to look at how we retrieve the inner contents of a page (nested contents)
or information about subpages (related contents) because I have a pretty good idea how
we want to cope with those bits in both cases.

The query syntax here is just pseudocode, I'm not proposing it:

boutell

<?php

$file = dirname(__FILE__) . '/profile.csv';

$out = fopen($file, 'a');

$load = @file_get_contents('/proc/loadavg');
$load = preg_split('/ /', $load);
$load = $load[0];

boutell

/** 
 * Create a situation where a unique index error will occur. Try to save the
 * object again after making the relevant field unique. Expected behavior:
 * object saves second (or third...) time and we wind up with ten objects. Actual behavior: 
 * we get just one object and there is a unique index error after all ten save callbacks
 * have already been invoked "successfully"! This is really strange, even stranger than I
 * thought. Maybe the index is not applied yet somehow and I need to wait on the schema
 * being ready?
 *

boutell

/** 
 * Create a situation where a unique index error will occur. Try to save the
 * object again after making the relevant field unique. Then do an update on one of the objects.
 *
 * Expected behavior: each object after the first saves successfully the second (or third...) time and we wind 
 * up with ten objects. Actual behavior with current Mongoose: we wind up with one object because the
 * isNew flag is never reset to true when an insert fails. Behavior with my pull request: the isNew flag
 * is reset if an insert (not an update) fails, allowing save handlers to try again on error after doing things
 * like making slugs more unique.
 *

boutell

// Extend any Mongoose model that has a unique index on a 'slug' field so that
// if a unique index error occurs on 'slug', a random digit is added to the slug
// and the save operation is retried until it works. This is concurrency-safe even 
// if you have lots of inserts going on from multiple machines etc.
//
// By Tom Boutell, tom@punkave.com
//
// NOTE: YOU MUST HAVE THIS PULL REQUEST... https://github.com/LearnBoost/mongoose/pull/837
//
// (As of this writing that commit is not in LearnBoost/mongoose yet.)

boutell

<?php

 define('NUM_TESTS', 1000);

 $before = memory_get_usage(true);

 $test = array();

 class Foo
 {

boutell

macintosh-5:~ boutell$ set | grep PATH
MANPATH=/opt/local/share/man:
PATH=/Users/boutell/mongodb/bin:/usr/local/bin:.:/Users/boutell/bin:/Users/boutell/.gem/bin:/opt/symfony1.4/data/bin:/opt/local/bin:/opt/local/sbin:/opt/local/apache2/bin:/Users/boutell/personalassistant/festival/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin:/opt/pktools/bin
macintosh-5:~ boutell$ 

boutell

		// If there are no matches, getSingleScalarResult will throw an exception
		try
		{
			$this->numResults = $countQb->getQuery()->getSingleScalarResult();
		} catch (\Doctrine\ORM\NoResultException $e)
		{
			// This happens when zero rows are returned
			$this->numResults = 0;
		}

boutell

// In my Search entity class:

    /**
     * @ORM\ManyToOne(targetEntity="Posting", inversedBy="words")
     * @ORM\JoinColumn(name="posting_id", referencedColumnName="id", onDelete="cascade")
     */
    protected $posting;

// Later, when I want to delete the Search objects for a given Posting entity: