# How to set pdf options using Export command

I found that there is an options using right click "save graphic as pdf", like this

I test "using most compatible vector representation", and result is good.

But how to set these options in Export? If I use Export directly like

Export['test.pdf',DensityPlot[Sin[x y],{x,1,10},{y,1,10},PlotPoints->30,MaxRecursion->3]]


The result pdf is 67MB !!! And it looks quite bad in my pdf xchange editor. Like this

However, if save it using "using most compatible vector representation" option, the pdf is only 3.9MB, and quality is quite good and it is vector image. like this