Is decarboxylation a necessary step in hash oil manufacture?

[fsmites]

howdy folks. I am a moderately experienced cold-water-extraction hash maker, but i have pretty minimal experience in making hash oil. to my understanding, cannabis needs to be heated for the thc to become psychoactive. upon checking recipes using various solvents(butane, acetone, isopropyl alcohol, etc) online, i have read mixed input on as to whether heating cannabis BEFORE starting the oil making process is necessary or not. i never heated my cannabis trim before making cold water extracted hash, so i didnt assume it would be necessary to do before making oil. like i said, i am about to embark on my first time making oil, and would appreciate any input from experienced oil makers out there on this subject. here Decarboxylation | Cannabis Culture Magazine is a link regarding the definition of decarboxylation by ed rosenthal.(gotta love ed!) "However, if you plan to vaporize or smoke the extract decarboxylation will take place as the oil is used."----says ed, but i have found a number of recipes that involve heating cannabis prior to even the extraction. for example, here: Simple Guide to Best Quality Hash Oil and Crystals (70 - 99% Pure THC) - Grasscity.com Forums i conclude from eds article that this is unnecessary, but if anyone on here has any experience to the contrary that decarboxylzing before extraction produces a higher quality product, i would love to hear from you. thanks.