基于前文,创建索引的时候有一个问题
每个bigint类型包括60个记录的位信息.
但是第0位表示第六十个记录的位
第1位至第59位表示第一至五十九的记录的位信息.
这样记录的位信息保存并不连续,
使用的时候还得把最右边的一位挪到最左边,不好理解还非常麻烦,性能也有损耗.
经过王工的改良,
使用如下sql替换，则保存的位信息就连续了
SELECT CEIL(id / 60) g60, CEIL(id / 1200) g1200, age grouped, COUNT(*) total, BIT_OR(1 << (if(MOD(id, 60)=0,60,MOD(id, 60)))) bitmap FROM o_huaxiang_big_0 o GROUP BY g1200 , g60 , age
创建位图索引的整体SQL如下
truncate table bitmap20_0; insert into bitmap20_0 select 'o_huaxiang_big' table_name, 'umc_sex' column_name, ((g1200-1)*60)*20 min_id, ((g1200-1)*60)*20+1200 max_id, v2.* from ( select g1200, grouped, sum(total) total, ifnull(max(case when abs((g1200-1)*20-g60)=20 then bitmap else null end),0) c20, ifnull(max(case when abs((g1200-1)*20-g60)=19 then bitmap else null end),0) c19, ifnull(max(case when abs((g1200-1)*20-g60)=18 then bitmap else null end),0) c18, ifnull(max(case when abs((g1200-1)*20-g60)=17 then bitmap else null end),0) c17, ifnull(max(case when abs((g1200-1)*20-g60)=16 then bitmap else null end),0) c16, ifnull(max(case when abs((g1200-1)*20-g60)=15 then bitmap else null end),0) c15, ifnull(max(case when abs((g1200-1)*20-g60)=14 then bitmap else null end),0) c14, ifnull(max(case when abs((g1200-1)*20-g60)=13 then bitmap else null end),0) c13, ifnull(max(case when abs((g1200-1)*20-g60)=12 then bitmap else null end),0) c12, ifnull(max(case when abs((g1200-1)*20-g60)=11 then bitmap else null end),0) c11, ifnull(max(case when abs((g1200-1)*20-g60)=10 then bitmap else null end),0) c10, ifnull(max(case when abs((g1200-1)*20-g60)=9 then bitmap else null end),0) c9, ifnull(max(case when abs((g1200-1)*20-g60)=8 then bitmap else null end),0) c8, ifnull(max(case when abs((g1200-1)*20-g60)=7 then bitmap else null end),0) c7, ifnull(max(case when abs((g1200-1)*20-g60)=6 then bitmap else null end),0) c6, ifnull(max(case when abs((g1200-1)*20-g60)=5 then bitmap else null end),0) c5, ifnull(max(case when abs((g1200-1)*20-g60)=4 then bitmap else null end),0) c4, ifnull(max(case when abs((g1200-1)*20-g60)=3 then bitmap else null end),0) c3, ifnull(max(case when abs((g1200-1)*20-g60)=2 then bitmap else null end),0) c2, ifnull(max(case when abs((g1200-1)*20-g60)=1 then bitmap else null end),0) c1 from ( SELECT CEIL(id / 60) g60, CEIL(id / 1200) g1200, umc_sex grouped, COUNT(*) total, BIT_OR(1 << (if(MOD(id, 60)=0,60,MOD(id, 60)))) bitmap FROM o_huaxiang_big_0 o GROUP BY g1200 , g60 , umc_sex ) v1 group by g1200,grouped ) v2; insert into bitmap20_0 select 'o_huaxiang_big' table_name, 'age' column_name, ((g1200-1)*60)*20 min_id, ((g1200-1)*60)*20+1200 max_id, v2.* from ( select g1200, grouped, sum(total) total, ifnull(max(case when abs((g1200-1)*20-g60)=20 then bitmap else null end),0) c20, ifnull(max(case when abs((g1200-1)*20-g60)=19 then bitmap else null end),0) c19, ifnull(max(case when abs((g1200-1)*20-g60)=18 then bitmap else null end),0) c18, ifnull(max(case when abs((g1200-1)*20-g60)=17 then bitmap else null end),0) c17, ifnull(max(case when abs((g1200-1)*20-g60)=16 then bitmap else null end),0) c16, ifnull(max(case when abs((g1200-1)*20-g60)=15 then bitmap else null end),0) c15, ifnull(max(case when abs((g1200-1)*20-g60)=14 then bitmap else null end),0) c14, ifnull(max(case when abs((g1200-1)*20-g60)=13 then bitmap else null end),0) c13, ifnull(max(case when abs((g1200-1)*20-g60)=12 then bitmap else null end),0) c12, ifnull(max(case when abs((g1200-1)*20-g60)=11 then bitmap else null end),0) c11, ifnull(max(case when abs((g1200-1)*20-g60)=10 then bitmap else null end),0) c10, ifnull(max(case when abs((g1200-1)*20-g60)=9 then bitmap else null end),0) c9, ifnull(max(case when abs((g1200-1)*20-g60)=8 then bitmap else null end),0) c8, ifnull(max(case when abs((g1200-1)*20-g60)=7 then bitmap else null end),0) c7, ifnull(max(case when abs((g1200-1)*20-g60)=6 then bitmap else null end),0) c6, ifnull(max(case when abs((g1200-1)*20-g60)=5 then bitmap else null end),0) c5, ifnull(max(case when abs((g1200-1)*20-g60)=4 then bitmap else null end),0) c4, ifnull(max(case when abs((g1200-1)*20-g60)=3 then bitmap else null end),0) c3, ifnull(max(case when abs((g1200-1)*20-g60)=2 then bitmap else null end),0) c2, ifnull(max(case when abs((g1200-1)*20-g60)=1 then bitmap else null end),0) c1 from ( SELECT CEIL(id / 60) g60, CEIL(id / 1200) g1200, age grouped, COUNT(*) total, BIT_OR(1 << (if(MOD(id, 60)=0,60,MOD(id, 60)))) bitmap FROM o_huaxiang_big_0 o GROUP BY g1200 , g60 , age ) v1 group by g1200,grouped ) v2;