MongoCollection::parallelCollectionScan

(PECL mongo >=1.5.0)

MongoCollection::parallelCollectionScanReturns an array of cursors to iterator over a full collection in parallel

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public MongoCollection::parallelCollectionScan ( int $num_cursors ) : array[MongoCommandCursor]

This method returns an array of a maximum of num_cursors cursors. An iteration over one of the returned cursors results in a partial set of documents for a collection. Iteration over all the returned cursors results in getting every document back from the collection.

This method is a wrapper for the parallelCollectionScan MongoDB command.

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num_cursors

The number of cursors to request from the server. Please note, that the server can return less cursors than you requested.

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Returns an array of MongoCommandCursor objects.

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Example #1 MongoCollection::parallelCollectionScan() example

Returning all documents in a collection by using multiple cursors.

<?php
$m 
= new MongoClient;
$c $m->demo->cities;

/* Request three cursors */
$cursors $c->parallelCollectionScan);

/* Add all the cursors to the MultipleIterator */
$mi = new MultipleIteratorMultipleIterator::MIT_NEED_ANY );
foreach ( 
$cursors as $cursor )
{
    
$mi->attachIterator$cursor );
}

/* Iterate over all the associated cursors */
foreach ( $mi as $items )
{
    foreach ( 
$items as $item )
    {
        if ( 
$item !== NULL )
        {
            echo 
$item['name'], "\n";
        }
    }
}
?>

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