Definition
Parameters
- $options: array
- An array specifying the desired options. NameTypeDescription- bucketName - string - The bucket name, which will be used as a prefix for the files and chunks collections. Defaults to - "fs".- chunkSizeBytes - integer - The chunk size in bytes. Defaults to - 261120(i.e. 255 KiB).- codec - MongoDB\Codec\DocumentCodec - The default Encode Data with Type Codecs to use for bucket methods that return a file document (e.g. - MongoDB\GridFS\Bucket::find()).- New in version 1.17. - disableMD5 - boolean - Whether to disable automatic MD5 generation when storing files. - Defaults to - false. Only- truewill be supported in 2.0.- New in version 1.4. - readConcern - The default read concern to use for bucket operations. Defaults to the database's read concern. - readPreference - The default read preference to use for bucket operations. Defaults to the database's read concern. - typeMap - array - The default type map to use for bucket operations. Defaults to the database's type map. - writeConcern - The default write concern to use for bucket operations. Defaults to the database's write concern. 
Return Values
A MongoDB\GridFS\Bucket object.
Errors/Exceptions
MongoDB\Exception\InvalidArgumentException for errors related to
the parsing of parameters or options.
Behavior
The selected bucket inherits options such as read preference and type
mapping from the Database object. Options may be
overridden via the $options parameter.
Example
The following example selects the default fs.files bucket in the test
database:
$db = (new MongoDB\Client)->test; $bucket = $db->selectGridFSBucket(); 
The following example selects the custom images.files bucket in the test
database with a custom read preference:
$db = (new MongoDB\Client)->test; $imagesBucket = $db->selectGridFSBucket([     'bucketName' => 'images',     'readPreference' => new MongoDB\Driver\ReadPreference('primaryPreferred'), ]);