The first thing to note is that this psalm is part of a collection of three psalms in Book Five of the Psalter. The three psalms are 108-110; all are attributed to David. Psalms 108 and 109 are "lament psalms." This means they lament the state of things--things are not as they should be.
Psalm 108 is a community lament. The writer awaits deliverance for the whole community from their common enemies. Psalm 109 is an individual lament. Here, the writer details the problems he has as someone who lives innocently before God but is besieged by people who accuse him.
When we read this grouping of three psalms, however, we find that Psalm 110 answers to two laments. The answer is God's King. God's King will be over all his enemies; they will be his footstool. He will execute judgment and bring about vindication for God's people.
If we look deeper at the violent questioning of Psalms 108 and 109, we see that they are really praying for deliverance (108:12-13; 109:26-27). The violence of their requests is part of their prayers for deliverance. They release their anger and desire for retribution to God. They do not take matters into their own hands. Instead, they wait confidently and in hope. They pray for deliverance. And the message of the Psalter is that God delivers.
How do you pray about the disappointments and discouragements of your life?