Code:
UPDATE spawn2 SET respawntime = X
replace x with any number and that will be your spawn time(in seconds)
Code:
UPDATE spawn2 SET respawntime = '*.5'
That will cut all respawns in half.
Code:
UPDATE spawn2 SET respawntime = * .5 WHERE respawntime >= X
That will half any spawntime greater, or equal to X, it's all in seconds.