[jira] [Closed] (HAWQ-800) Less tuple is inserted due to data locality information is not refreshed and dispatched in prepared statement

["Ruilong Huo (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HAWQ-800?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Ruilong Huo closed HAWQ-800.
----------------------------

> Less tuple is inserted due to data locality information is not refreshed and dispatched in prepared statement
> -------------------------------------------------------------------------------------------------------------
>
>                 Key: HAWQ-800
>                 URL: https://issues.apache.org/jira/browse/HAWQ-800
>             Project: Apache HAWQ
>          Issue Type: Bug
>          Components: Core, Dispatcher, Query Execution, Resource Manager
>    Affects Versions: 2.0.0
>            Reporter: Ruilong Huo
>            Assignee: Ruilong Huo
>             Fix For: 2.0.0
>
>         Attachments: proba.out, proba.sql, proba_execute.out, proba_execute.sql
>
>
> In either explicit (SQL) or implicit (UDF) prepared statement, there is less tuple inserted if we run a prepared "insert into t select * from t" plan multiple times in a transaction.
> Below is a simple case to reproduce this issue. For a more complicated example, you may refer to attached proba_execute and proba.
> 1. There should be 8 tuples, however there is only 4 in hawq 2.0
> {noformat}
> drop table if exists t;
> DROP TABLE
> create table t (id int);
> CREATE TABLE
> insert into t values (1);
> INSERT 0 1
> CREATE OR REPLACE FUNCTION f_load()
> RETURNS TEXT
> LANGUAGE plpgsql
> AS
> $body$
> DECLARE
>     l_rec RECORD;
>     l_itm RECORD;
> BEGIN
>     FOR l_rec IN ( SELECT generate_series(1, 3) AS id )
>     LOOP
>         INSERT INTO t SELECT * FROM t;
>     END LOOP;
>     RETURN 'done';
> END;
> $body$
> ;
> CREATE FUNCTION
> SELECT f_load();
>  f_load
> --------
>  done
> (1 row)
> SELECT * FROM t;
>  id
> ----
>   1
>   1
>   1
>   1
> (4 rows)
> {noformat}
> 2. There are 8 tuples as expected in hawq 1.x
> {noformat}
> drop table if exists t;
> DROP TABLE
> create table t (id int);
> psql:temp.sql:3: NOTICE:  Table doesn't have 'DISTRIBUTED BY' clause -- Using column named 'id' as the Greenplum Database data distribution key for this table.
> HINT:  The 'DISTRIBUTED BY' clause determines the distribution of data. Make sure column(s) chosen are the optimal data distribution key to minimize skew.
> CREATE TABLE
> insert into t values (1);
> INSERT 0 1
> CREATE OR REPLACE FUNCTION f_load()
> RETURNS TEXT
> LANGUAGE plpgsql
> AS
> $body$
> DECLARE
>     l_rec RECORD;
>     l_itm RECORD;
> BEGIN
>     FOR l_rec IN ( SELECT generate_series(1, 3) AS id )
>     LOOP
>         INSERT INTO t SELECT * FROM t;
>     END LOOP;
>     RETURN 'done';
> END;
> $body$
> ;
> CREATE FUNCTION
> SELECT f_load();
>  f_load
> --------
>  done
> (1 row)
> SELECT * FROM t;
>  id
> ----
>   1
>   1
>   1
>   1
>   1
>   1
>   1
>   1
> (8 rows)
> {noformat}



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