SPARK-18367 <https://issues.apache.org/jira/browse/SPARK-18367>: limit()
makes the lame walk again
On Tue, Nov 8, 2016 at 5:00 PM Nicholas Chammas <nicholas.cham...@gmail.com>
wrote:
> Hmm, it doesn’t seem like I can access the output of
> df._jdf.queryExecution().hiveResultString() from Python, and until I can
> boil the issue down a bit, I’m stuck with using Python.
>
> I’ll have a go at using regexes to strip some stuff from the printed
> plans. The one that’s working for me to strip the IDs is #\d+L?.
>
> Nick
>
>
> On Tue, Nov 8, 2016 at 4:47 PM Reynold Xin <r...@databricks.com> wrote:
>
> If you want to peek into the internals and do crazy things, it is much
> easier to do it in Scala with df.queryExecution.
>
> For explain string output, you can work around the comparison simply by
> doing replaceAll("#\\d+", "#x")
>
> similar to the patch here:
> https://github.com/apache/spark/commit/fd90541c35af2bccf0155467bec8cea7c8865046#diff-432455394ca50800d5de508861984ca5R217
>
>
>
> On Tue, Nov 8, 2016 at 1:42 PM, Nicholas Chammas <
> nicholas.cham...@gmail.com> wrote:
>
> I’m trying to understand what I think is an optimizer bug. To do that, I’d
> like to compare the execution plans for a certain query with and without a
> certain change, to understand how that change is impacting the plan.
>
> How would I do that in PySpark? I’m working with 2.0.1, but I can use
> master if it helps.
>
> explain()
> <http://spark.apache.org/docs/latest/api/python/pyspark.sql.html#pyspark.sql.DataFrame.explain>
> is helpful but is limited in two important ways:
>
> 1. It prints to screen and doesn’t offer another way to access the
> plan or capture it.
> 2.
>
> The printed plan includes auto-generated IDs that make diffing
> impossible. e.g.
>
> == Physical Plan ==
> *Project [struct(primary_key#722, person#550, dataset_name#671)
>
>
> Any suggestions on what to do? Any relevant JIRAs I should follow?
>
> Nick
>
>
>
>
