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Posted to issues@hive.apache.org by "liyunzhang_intel (JIRA)" <ji...@apache.org> on 2017/06/07 03:18:18 UTC
[jira] [Assigned] (HIVE-16840) Investigate the performance of order
by limit in HoS
[ https://issues.apache.org/jira/browse/HIVE-16840?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
liyunzhang_intel reassigned HIVE-16840:
---------------------------------------
> Investigate the performance of order by limit in HoS
> ----------------------------------------------------
>
> Key: HIVE-16840
> URL: https://issues.apache.org/jira/browse/HIVE-16840
> Project: Hive
> Issue Type: Bug
> Reporter: liyunzhang_intel
> Assignee: liyunzhang_intel
>
> We found that on 1TB data of TPC-DS, q17 of TPC-DS hanged.
> {code}
> select i_item_id
> ,i_item_desc
> ,s_state
> ,count(ss_quantity) as store_sales_quantitycount
> ,avg(ss_quantity) as store_sales_quantityave
> ,stddev_samp(ss_quantity) as store_sales_quantitystdev
> ,stddev_samp(ss_quantity)/avg(ss_quantity) as store_sales_quantitycov
> ,count(sr_return_quantity) as_store_returns_quantitycount
> ,avg(sr_return_quantity) as_store_returns_quantityave
> ,stddev_samp(sr_return_quantity) as_store_returns_quantitystdev
> ,stddev_samp(sr_return_quantity)/avg(sr_return_quantity) as store_returns_quantitycov
> ,count(cs_quantity) as catalog_sales_quantitycount ,avg(cs_quantity) as catalog_sales_quantityave
> ,stddev_samp(cs_quantity)/avg(cs_quantity) as catalog_sales_quantitystdev
> ,stddev_samp(cs_quantity)/avg(cs_quantity) as catalog_sales_quantitycov
> from store_sales
> ,store_returns
> ,catalog_sales
> ,date_dim d1
> ,date_dim d2
> ,date_dim d3
> ,store
> ,item
> where d1.d_quarter_name = '2000Q1'
> and d1.d_date_sk = store_sales.ss_sold_date_sk
> and item.i_item_sk = store_sales.ss_item_sk
> and store.s_store_sk = store_sales.ss_store_sk
> and store_sales.ss_customer_sk = store_returns.sr_customer_sk
> and store_sales.ss_item_sk = store_returns.sr_item_sk
> and store_sales.ss_ticket_number = store_returns.sr_ticket_number
> and store_returns.sr_returned_date_sk = d2.d_date_sk
> and d2.d_quarter_name in ('2000Q1','2000Q2','2000Q3')
> and store_returns.sr_customer_sk = catalog_sales.cs_bill_customer_sk
> and store_returns.sr_item_sk = catalog_sales.cs_item_sk
> and catalog_sales.cs_sold_date_sk = d3.d_date_sk
> and d3.d_quarter_name in ('2000Q1','2000Q2','2000Q3')
> group by i_item_id
> ,i_item_desc
> ,s_state
> order by i_item_id
> ,i_item_desc
> ,s_state
> limit 100;
> {code}
> the reason why the script hanged is because we only use 1 task to implement sort.
> {code}
> STAGE PLANS:
> Stage: Stage-1
> Spark
> Edges:
> Reducer 10 <- Reducer 9 (SORT, 1)
> Reducer 2 <- Map 1 (PARTITION-LEVEL SORT, 889), Map 11 (PARTITION-LEVEL SORT, 889)
> Reducer 3 <- Map 12 (PARTITION-LEVEL SORT, 1009), Reducer 2 (PARTITION-LEVEL SORT, 1009)
> Reducer 4 <- Map 13 (PARTITION-LEVEL SORT, 683), Reducer 3 (PARTITION-LEVEL SORT, 683)
> Reducer 5 <- Map 14 (PARTITION-LEVEL SORT, 751), Reducer 4 (PARTITION-LEVEL SORT, 751)
> Reducer 6 <- Map 15 (PARTITION-LEVEL SORT, 826), Reducer 5 (PARTITION-LEVEL SORT, 826)
> Reducer 7 <- Map 16 (PARTITION-LEVEL SORT, 909), Reducer 6 (PARTITION-LEVEL SORT, 909)
> Reducer 8 <- Map 17 (PARTITION-LEVEL SORT, 1001), Reducer 7 (PARTITION-LEVEL SORT, 1001)
> Reducer 9 <- Reducer 8 (GROUP, 2)
> {code}
> The parallelism of Reducer 9 is 1. It is a orderby limit case so we use 1 task to execute to ensure the correctness. But the performance is poor.
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