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From Guillermo Ortiz <konstt2...@gmail.com>
Subject Re: GroupBy with index is really slow.
Date Wed, 10 May 2017 15:27:06 GMT
If I execute many times, time is similar in both.

2017-05-10 17:25 GMT+02:00 Guillermo Ortiz <konstt2000@gmail.com>:

> I'm using 2.0.0.
> Right now in my laptop with 2Mill objects.
>
>
> *WITH INDICES*
> ******Result SELECT distinct(MONTH) FROM PERSONWITHINDEX
> September,February,March,August,June,April,July,
> January,May,November,October,
> Elapsed time SELECT distinct(MONTH) FROM PERSONWITHINDEX:1990ms
> [SELECT DISTINCT
>     __Z0.MONTH AS __C0_0
> FROM "PersonWithIndex".PERSONWITHINDEX __Z0
>     /* "PersonWithIndex".PERSONWITHINDEX_MONTH_IDX */]
> [SELECT DISTINCT
>     __C0_0 AS MONTH
> FROM PUBLIC.__T0
>     /* "PersonWithIndex"."merge_scan" */]
>
>
> *WITHOUT INDICES*
> ******Result SELECT distinct(MONTH) FROM PERSONWITHOUTINDEX
> September,November,February,March,May,April,July,August,
> January,June,October,
> Elapsed time SELECT distinct(MONTH) FROM PERSONWITHOUTINDEX:1690ms
> [SELECT DISTINCT
>     __Z0.MONTH AS __C0_0
> FROM "PersonWithoutIndex".PERSONWITHOUTINDEX __Z0
>     /* "PersonWithoutIndex".PERSONWITHOUTINDEX.__SCAN_ */]
> [SELECT DISTINCT
>     __C0_0 AS MONTH
> FROM PUBLIC.__T0
>     /* "PersonWithoutIndex"."merge_scan" */]
> ***************************
>
> public class PersonWithIndex implements Serializable {
>     @QuerySqlField(index = true)
>     public int id;
>     @QuerySqlField(index = true, orderedGroups = {@QuerySqlField.Group(name="index_group_month_age",
order=1)})
>     public int age;
>     @QuerySqlField
>     public String dni;
>     @QuerySqlField(index = true, orderedGroups = {@QuerySqlField.Group(name="index_group_month_age",
order=0)})
>     public String month;
>
>
> 2017-05-10 17:06 GMT+02:00 afedotov <alexander.fedotoff@gmail.com>:
>
>> Hi,
>>
>> Which Ignite version do you use?
>> How many Ignite nodes do you run?
>> What is your cache configuration?
>>
>> As well, could you please try the following query and see the performance?
>> SELECT DISTINCT age FROM PersonWithindex;
>>
>>
>> Kind regards,
>> Alex.
>>
>> On Wed, May 10, 2017 at 5:57 PM, Guillermo Ortiz [via Apache Ignite
>> Users] <[hidden email]
>> <http:///user/SendEmail.jtp?type=node&node=12593&i=0>> wrote:
>>
>>> It's my laptop. 16gb, i7.. The collection size it's 5Mill objects
>>> (1,2GB) and it takes about 30sec.
>>> I have tried to execute the query with the same collection with and
>>> without indices with the same time results.
>>>
>>> This is a test before to run in the real cluster with 6 nodes of 512Gb
>>> and 48cores each one. We tried to execute there with a real dataset(22M
>>> rows, 7gb) but it takes so long that query is aborted.
>>>
>>>
>>> 2017-05-08 12:12 GMT+02:00 Andrey Mashenkov <[hidden email]
>>> <http:///user/SendEmail.jtp?type=node&node=12592&i=0>>:
>>>
>>>> Hi,
>>>>
>>>> Why do you think query is slow?
>>>> What its execution time? What is expected time?
>>>> How many nodes do you use? How much data does cache contains?
>>>>
>>>> On Mon, May 8, 2017 at 1:47 AM, Guillermo Ortiz <[hidden email]
>>>> <http:///user/SendEmail.jtp?type=node&node=12592&i=1>> wrote:
>>>>
>>>>> I have a simple cache where I have Person object (id, age and so on..)
>>>>>
>>>>> I have created indeces by id and age to try some examples but queries
>>>>> with "group by" go really slow.
>>>>>
>>>>> I'm trying this query:
>>>>> SELECT age
>>>>> FROM
>>>>> PersonWithindex
>>>>> group by age
>>>>>
>>>>>
>>>>> SELECT
>>>>>     AGE AS __C0
>>>>> FROM "personCacheWithIndex".PERSONWITHINDEX
>>>>>     /* "personCacheWithIndex"."age_idx" */
>>>>> GROUP BY AGE
>>>>> /* group sorted */
>>>>>
>>>>> SELECT
>>>>>     __C0 AS AGE
>>>>> FROM PUBLIC.__T0
>>>>>     /* "personCacheWithIndex"."merge_scan" */
>>>>> GROUP BY __C0
>>>>>
>>>>> Although it seems that it uses index, why is it going so slow? I think
>>>>> that it should be pretty fast with an index.
>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> Best regards,
>>>> Andrey V. Mashenkov
>>>>
>>>
>>>
>>>
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>>
>>
>> ------------------------------
>> View this message in context: Re: GroupBy with index is really slow.
>> <http://apache-ignite-users.70518.x6.nabble.com/GroupBy-with-index-is-really-slow-tp12526p12593.html>
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>
>

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