Constraints

Using constraints in a query can speed up a search operation as they limit the scope of data that needs to be searched. Constraints enable you to limit a query to events from one or more of the following:

Particular device groups
Particular storage groups
Specific peers

For information about storage groups and peers, see Storage, Device Groups, and Peer Nodes.

Follow these guidelines when specifying constraints:

Use the following operators to specify constraints in a search query expression:

Metadata Identifier Example

Metadata Identifier	Example
_deviceGroup	_deviceGroup IN [“DM1”, “HostA”] where `DM1` is a device group, while `HostA` is a device. Note: You can use this field to specify individual devices.
_storageGroup	_storageGroup IN [“Internal Event Storage Group”, “SG1”]
_peerLogger	_peerLogger IN [“192.0.2.10”, “192.0.2.11”]

_deviceGroup

_deviceGroup IN [“DM1”, “HostA”]

where DM1 is a device group, while HostA is a device.

Note: You can use this field to specify individual devices.

_storageGroup

_storageGroup IN [“Internal Event Storage Group”, “SG1”]

_peerLogger

_peerLogger IN [“192.0.2.10”, “192.0.2.11”]

If a query includes the Boolean operator OR and metadata identifiers, the expression to be evaluated with OR must be enclosed in parentheses, as shown in this example:
```
(success OR fail) _storageGroup IN [“Default Storage Group”]
```
If the expression to be evaluated with OR is not enclosed in parentheses, an error message is displayed on the user interface screen.
When specifying multiple groups in a constraint, ensure that the group names are enclosed in square brackets; for example, _storageGroup IN [“SGA”, “SGB”].
You can apply constraints to a search query by:
1. Typing the constraint in the Search text box.
  
  Once you type “_s” (for storage group), “_d” (for device group), or “_p” (for peer) in the Search text box, Search Helper automatically provides a drop-down list of relevant terms and operators from which you can select.
  
  Caution: If a search query contains constraints and a regular expression, make sure that the constraints are specified before the regular expression. For example, _peerLogger IN [“192.0.2.10”] name contains abc | REGEX=“:\d31”
2. Selecting Storage Groups or peers from the Advanced Search tool. To access the Advanced Search tool, click Advanced Search beneath the text box where you type the query. See Classic Search: Using the Advanced Search Builder.