Managing security policy

A network security device comprising:

• a processor and a computer-readable storage medium storing machine readable instructions that are executable by the processor to:
• determine whether a number of rules with a same matching feature in a first policy database reaches a preset threshold, wherein the first policy database records one or more first policies, each of the first policies comprises a policy identity (ID) and a plurality of rules respectively associated with the policy ID, each of the rules comprises a matching feature and an action associated with the matching feature;
• and
• generate a second policy database recording one or more second policies, by reconstructing the first policies in the first policy database when the number of rules with the same matching feature reaches the preset threshold, wherein each of the second policies comprises a matching feature and a target two-tuple comprising a policy id and an action associated with the matching feature.