Support events qualified for multiple conditions.

[amosbird]

Currently windowFunnel function only takes the first qualified event condition
into account when operating on one event. This patch extends the
ability.

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[sundy-li]

Thank you, but how to avoid duplicate match?
Eg.
windowFunnel(4)(timestamp, event <= 2, event <=4, event <=6, event <=8)
There's just one row data with event = 2 , but it could have the result 4.

[amosbird]

Well, I answered that question in the related comment :-) lemme expand that here with your example.

Consider a table with timestamp : 1 and event : 1

with this windowFunnel(4)(timestamp, event <= 2, event <=4, event <=6, event <=8) invocation, it generates four entries in the event list with the order (1001, 4), (1001, 3), (1001, 2), (1001, 1) and this order is kept via stable sort. (Note, merging sort itself is stable too). Thus, when doing forward scan over the event list, no duplication result would be generated.

[sundy-li]

I got it, nice solution.

[VadimPlh]

@amosbird Hi! Thanks for your PR! Your code has problems with test(00678_shard_funnel_window). I try to fix it.

[amosbird]

@VadimPE Hi, I didn't see failures in test 678 and there isn't a related commit in recent commit log. What problem is it?

[VadimPlh]

@amosbird

In this case
CREATE TABLE test.remote_test(uid String, its UInt32, action_code String, day Date) ENGINE = MergeTree(day, (uid, its), 8192);
INSERT INTO test.remote_test SELECT toString(number) AS uid, number % 3 AS its, toString(number % 3) AS action_code, '2000-01-01' FROM system.numbers LIMIT 10000;
SELECT level, COUNT() FROM (SELECT uid, windowFunnel(3600)(toUInt32(its), action_code != '', action_code = '2') AS level FROM remote('127.0.0.{2,3}', test.remote_test) GROUP BY uid) GROUP BY level;

old version: 1 10000
your version:
1 - 6667
2 - 3333

[amosbird]

Well that's expected. The correct output should be

1 - 6667
2 - 3333

Old version doesn't work when the some filter includes others, and this is what my patch meant to fix.

[VadimPlh]

@amosbird #3032