Validate Command

Use this command to check that a collection is valid (not corrupt) and to get various statistics.

This command scans the entire collection and its indexes and will be very slow on large datasets.

option	description
full	Validates everything – new in 2.0.0
scandata	Validates basics (index/collection-stats) and document headers

Blocking
This is a blocking operation (like Repair Database Command).

From the mongo shell:

> db.foo.validate({full:true})
{
	"ns" : "test.foo",
	"firstExtent" : "0:109c00 ns:test.foo",
	"lastExtent" : "0:2e0d00 ns:test.foo",
	"extentCount" : 3,
	"extents" : [
		{
			"loc" : "0:109c00",
			"xnext" : "0:192000",
			"xprev" : "null",
			"nsdiag" : "test.foo",
			"size" : 12288,
			"firstRecord" : "0:109cb0",
			"lastRecord" : "0:10cb90"
		},
		{
			"loc" : "0:192000",
			"xnext" : "0:2e0d00",
			"xprev" : "0:109c00",
			"nsdiag" : "test.foo",
			"size" : 49152,
			"firstRecord" : "0:1920b0",
			"lastRecord" : "0:19df00"
		},
		{
			"loc" : "0:2e0d00",
			"xnext" : "null",
			"xprev" : "0:192000",
			"nsdiag" : "test.foo",
			"size" : 196608,
			"firstRecord" : "0:2e0db0",
			"lastRecord" : "0:30c820"
		}
	],
	"datasize" : 224112,
	"nrecords" : 1001,
	"lastExtentSize" : 196608,
	"padding" : 1,
	"firstExtentDetails" : {
		"loc" : "0:109c00",
		"xnext" : "0:192000",
		"xprev" : "null",
		"nsdiag" : "test.foo",
		"size" : 12288,
		"firstRecord" : "0:109cb0",
		"lastRecord" : "0:10cb90"
	},
	"objectsFound" : 1001,
	"invalidObjects" : 0,
	"bytesWithHeaders" : 240128,
	"bytesWithoutHeaders" : 224112,
	"deletedCount" : 1,
	"deletedSize" : 17392,
	"nIndexes" : 1,
	"keysPerIndex" : {
		"test.foo.$_id_" : 1001
	},
	"valid" : true,
	"errors" : [ ],
	"ok" : 1
}

Example From Driver

From a driver one might invoke the driver's equivalent of:

> db.$cmd.findOne({validate:"foo" } );

> db.$cmd.findOne({validate:"foo", full:true});

Validate Command

Example From Driver

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