mongocollection.parallelcollectionscan(3) [php man page]

MONGOCOLLECTION.PARALLELCOLLECTIONSCAN(3)				 1				 MONGOCOLLECTION.PARALLELCOLLECTIONSCAN(3)

MongoCollection::parallelCollectionScan - Returns an array of cursors to iterator over a full collection in parallel

SYNOPSIS

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

DESCRIPTION

	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.

PARAMETERS

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

RETURN VALUES

	Returns an array of MongoCommandCursor objects.

EXAMPLES

       Example #1

	      MongoCollection.parallelCollectionScan(3) 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( 3 );

	      /* Add all the cursors to the MultipleIterator */
	      $mi = new MultipleIterator( MultipleIterator::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'], "
";
		      }
		  }
	      }
	      ?>

SEE ALSO

       MultipleIterator, MongoCommandCursor, MongoDB::command.

PHP Documentation Group 										 MONGOCOLLECTION.PARALLELCOLLECTIONSCAN(3)

MONGOCOMMANDCURSOR(3)							 1						     MONGOCOMMANDCURSOR(3)

The MongoCommandCursor class

INTRODUCTION

	A  command  cursor is similar to a MongoCursor except that you use it for iterating through the results of a database command instead of a
       normal query. Command cursors are useful for iterating over large result sets that might exceed the document size limit (currently 16MB) of
       a single MongoDB.command(3) response.

	While  you  can  create  command  cursors  using MongoCommandCursor.__construct(3) or the MongoCommandCursor.createFromDocument(3) factory
       method, you will generally want to use command-specific helpers such as MongoCollection.aggregateCursor(3).

	Note that the cursor does not "contain" the database command's results; it just manages iteration through them. Thus, if you print a  cur-
       sor (f.e. with var_dump(3) or print_r(3)), you will see the cursor object but not the result documents.

CURSOR STAGES

	A MongoCommandCursor has two "life stages": pre- and post- command. When a cursor is created, it has not yet contacted the database, so it
       is in its pre-command state. When the client first attempts to get a result (by calling	MongoCommandCursor.rewind(3),  directly  or  indi-
       rectly), the cursor moves into the post-command state.

	The command cursor's batch size and socket timeout may be configured in both the pre- and post- command states.

       Example #1

	      Adding options to MongoCommandCursor

	      <?php

	      $cursor = new MongoCommandCursor(...);

	      $cursor = $cursor->batchSize( 4 );

	      foreach ($cursor as $result) {
		  var_dump($result);
	      }
	      ?>

CLASS SYNOPSIS

       MongoCommandCursor

       MongoCommandCursorMongoCursorInterfaceIterator

       Methods

       o public MongoCommandCursor MongoCommandCursor::batchSize (int  $batchSize)

       o public MongoCommandCursor::__construct (MongoClient  $connection, string  $ns, array  $command = array())

       o publicstatic MongoCommandCursor MongoCommandCursor::createFromDocument (MongoClient  $connection, string  $hash, array  $document)

       o public array MongoCommandCursor::current (void  )

       o public bool MongoCommandCursor::dead (void  )

       o public array MongoCommandCursor::getReadPreference (void  )

       o public array MongoCommandCursor::info (void  )

       o public int MongoCommandCursor::key (void  )

       o public void MongoCommandCursor::next (void  )

       o public array MongoCommandCursor::rewind (void	)

       o public MongoCommandCursor MongoCommandCursor::setReadPreference (string  $read_preference, [array  $tags])

       o public MongoCommandCursor MongoCommandCursor::timeout (int  $ms)

       o public bool MongoCommandCursor::valid (void  )

SEE ALSO

	      o MongoDB::command

	      o MongoCollection::aggregateCursor

PHP Documentation Group 												     MONGOCOMMANDCURSOR(3)