GitHub user herval opened a pull request:
https://github.com/apache/zeppelin/pull/2428
[ZEPPELIN-1470] limiting results from jdbc
### What is this PR for?
One thing we tracked down is that if you issue a large query on a very
large table, it will simply try to load all results (and then cap them on
Zeppelin's side), which seems suboptimal (and will freeze the server). Setting
this on the JDBC level seems to solve the problem.
### What type of PR is it?
Bug Fix
### Todos
* [ ] - Task
### How should this be tested?
- Create or use a table with a very large number of rows. In our tests, I
simply created a:
```
createdb zeppelin_test
psql zeppelin_test
create table too_many_rows(n int)
```
And added 5m rows to it.
Making a paragraph like this will hang without this:
```
%zeppelin_test
select * from too_many_rows
```
### Questions:
* Does the licenses files need update?
No
* Is there breaking changes for older versions?
No
* Does this needs documentation?
No
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/herval/zeppelin hfreire/limit-row-count
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/zeppelin/pull/2428.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #2428
----
commit f574f84706e4b345b62bebd456964928c4b787e8
Author: Herval Freire <hfre...@twitter.com>
Date: 2017-06-21T23:54:29Z
limiting results from jdbc
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