Roaring bitmaps
說(shuō)到Roaring bitmaps谢翎,就必須先從bitmap說(shuō)起婿禽。Bitmap是一種數(shù)據(jù)結(jié)構(gòu)咙俩,假設(shè)有某個(gè)posting list:
[1,3,4,7,10]
對(duì)應(yīng)的bitmap就是:
[1,0,1,1,0,0,1,0,0,1]
非常直觀壮锻,用0/1表示某個(gè)值是否存在,比如10這個(gè)值就對(duì)應(yīng)第10位倍靡,對(duì)應(yīng)的bit值是1