Returns an array of cursors to iterator over a full collection in parallel


(PECL mongo >=1.5.0)

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

Описание

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

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.

Список параметров

num_cursors

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

Возвращаемые значения

Returns an array of MongoCommandCursor objects.

Примеры

Пример #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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