zeromax007 / gpdb-roaringbitmap Goto Github PK

版本：Greenplum Database 6.0.0-beta.6 build dev
安装异常：

请问什么时候可以支持 bigint 呢?

I used your code with GP version 4.3.7.15, the registration of sql function for roaring bitmap operation is always failed.

I found the pgsql extern function of AggCheckCallContext is missing from C header file fmgr.h,
then I switched to the newest version of GP 5.0.0-beta.4, and all looks good.

Leave a note here to save the time for anyone who visits this looking for roaring bitmap in greenplum.

make 的时候有错误提示，变量未初始化，赋值 0后，可以正常编译

Greenplum/PostgreSQL has extension framework, which is easier to use and manage. Maybe it will be awesome if make this project as an extension.

Greenplum 版本：PostgreSQL 9.4.24 (Greenplum Database 6.2.1 build commit:d90ac1a1b983b913b3950430d4d9e47ee8827fd4) on x86_64-unknown-linux-gnu, compiled by gcc (GCC) 6.4.0, 64-bit compiled on Dec 12 2019 18:35:48

问题描述

有两个一样的脚本。其中一个脚本直接计算bitmap，另外一个脚本计算表内的bitmap。两个bitmap一致。但是使用 rb_and_agg 计算时，会出现不一样的结果。

脚本1：

select rb_to_array(rb_and_agg(bitmap))               as result,
       count(1)                                      as total,
       string_agg(rb_to_array(bitmap)::varchar, ',') as str
from (values (rb_build('{1,2,3}')), (rb_build('{2,3,4}'))) t(bitmap);

结果为：

正常。注释掉count(1) as total与string_agg(rb_to_array(bitmap)::varchar, ',') as str后，执行均正常得到and_agg计算结果。

脚本2：

select rb_to_array(rb_and_agg(bitmap))               as result,
       string_agg(rb_to_array(bitmap)::varchar, ',') as str
from (select bitmap from t_tmp where id in (4, 5) order by id) a;

其中表t_tmp内容为：

脚本2执行结果为：

此处正常。但是当把脚本2中的string_agg(rb_to_array(bitmap)::varchar, ',') as str注释后，将得到以下不正确的结果：

附录

表创建语句：

CREATE TABLE t_tmp
(
    id     integer,
    bitmap roaringbitmap
);
INSERT INTO t_tmp SELECT 4, rb_build('{1,2,3}');
INSERT INTO t_tmp SELECT 5, rb_build('{2,3,4}');

SQL：
CREATE TABLE t1 (id integer, bitmap roaringbitmap);

INSERT INTO t1 SELECT 3,RB_BUILD(ARRAY[1,2,3]);
INSERT INTO t1 SELECT 4,RB_BUILD(ARRAY[3,4,5]);
INSERT INTO t1 SELECT 5,RB_BUILD(ARRAY[-3,4,5]);

select id, rb_maximum(bitmap) from t1 where id in (3,4,5);
id | rb_maximum
----+------------
3 | 3
4 | 5
5 | -3

I think it should be
select id, rb_maximum(bitmap) from t1 where id in (3,4,5);
id | rb_maximum
----+------------
3 | 3
4 | 5
5 | 5

由于上一个issue无法reopen，所以我新开一个了。
参考：
#10 (comment)