[jira] [Commented] (HIVE-4590) HCatalog documentation example is wrong
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https://issues.apache.org/jira/browse/HIVE-4590?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=14068880#comment-14068880
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Lefty Leverenz commented on HIVE-4590:
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Done:
{quote}
The following very simple MapReduce program reads data from one table which it
assumes to have an integer in the second column (column 1), and counts how
many instances of each distinct value it finds. That is, it does the equivalent
of select col1, count\(*\) from $table group by col1;.
For example, if the values in the second column are \{1,1,1,3,3,5\} the program
will produce this output of values and counts:
1, 3
3, 2
5, 1
{quote}
* [HCatalog Input Output -- Read Example |
https://cwiki.apache.org/confluence/display/Hive/HCatalog+InputOutput#HCatalogInputOutput-ReadExample]
HCatalog documentation example is wrong
---
Key: HIVE-4590
URL: https://issues.apache.org/jira/browse/HIVE-4590
Project: Hive
Issue Type: Bug
Components: Documentation, HCatalog
Affects Versions: 0.10.0
Reporter: Eugene Koifman
Assignee: Lefty Leverenz
Priority: Minor
http://hive.apache.org/docs/hcat_r0.5.0/inputoutput.html#Read+Example
reads
The following very simple MapReduce program reads data from one table which
it assumes to have an integer in the second column, and counts how many
different values it sees. That is, it does the equivalent of select col1,
count(*) from $table group by col1;.
The description of the query is wrong. It actually counts how many instances
of each distinct value it find. For example, if values of col1 are
{1,1,1,3,3,3,5) it will produce
1, 3
3, 2,
5, 1
--
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[jira] [Commented] (HIVE-4590) HCatalog documentation example is wrong
[
https://issues.apache.org/jira/browse/HIVE-4590?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=14068095#comment-14068095
]
Lefty Leverenz commented on HIVE-4590:
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[~eugene.koifman], it's past time to fix this but first I have a couple of
questions:
# Why does the equivalent SELECT statement say col1 while the description
says an integer in the second column? Does this assume column numbers start
with zero?
#* select col1, count\(*\) from $table group by col1;
I tried to figure it out from the MR program, but strained my brain.
# Is there a typo in the output for your sample dataset (1,1,1,3,3,3,5)? I
see three 3s, not 2.
#* 1, 3
3, 2,
5, 1
... and presumably the comma after the 2 (or 3) can be removed.
The doc has a new location, by the way:
* [HCat Input and Output -- Read Example |
https://cwiki.apache.org/confluence/display/Hive/HCatalog+InputOutput#HCatalogInputOutput-ReadExample]
HCatalog documentation example is wrong
---
Key: HIVE-4590
URL: https://issues.apache.org/jira/browse/HIVE-4590
Project: Hive
Issue Type: Bug
Components: Documentation, HCatalog
Affects Versions: 0.10.0
Reporter: Eugene Koifman
Assignee: Lefty Leverenz
Priority: Minor
http://hive.apache.org/docs/hcat_r0.5.0/inputoutput.html#Read+Example
reads
The following very simple MapReduce program reads data from one table which
it assumes to have an integer in the second column, and counts how many
different values it sees. That is, it does the equivalent of select col1,
count(*) from $table group by col1;.
The description of the query is wrong. It actually counts how many instances
of each distinct value it find. For example, if values of col1 are
{1,1,1,3,3,3,5) it will produce
1, 3
3, 2,
5, 1
--
This message was sent by Atlassian JIRA
(v6.2#6252)
[jira] [Commented] (HIVE-4590) HCatalog documentation example is wrong
[
https://issues.apache.org/jira/browse/HIVE-4590?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=14068228#comment-14068228
]
Eugene Koifman commented on HIVE-4590:
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[~leftylev]
1. The MR program does value.get(1) in reduce() which means it's col1 is
the 2nd column. Presumably the 1st (0th) column could have been UserName.
2. you are correct on both
HCatalog documentation example is wrong
---
Key: HIVE-4590
URL: https://issues.apache.org/jira/browse/HIVE-4590
Project: Hive
Issue Type: Bug
Components: Documentation, HCatalog
Affects Versions: 0.10.0
Reporter: Eugene Koifman
Assignee: Lefty Leverenz
Priority: Minor
http://hive.apache.org/docs/hcat_r0.5.0/inputoutput.html#Read+Example
reads
The following very simple MapReduce program reads data from one table which
it assumes to have an integer in the second column, and counts how many
different values it sees. That is, it does the equivalent of select col1,
count(*) from $table group by col1;.
The description of the query is wrong. It actually counts how many instances
of each distinct value it find. For example, if values of col1 are
{1,1,1,3,3,3,5) it will produce
1, 3
3, 2,
5, 1
--
This message was sent by Atlassian JIRA
(v6.2#6252)
