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From GitBox <...@apache.org>
Subject [GitHub] bbevens closed pull request #1474: DRILL-6749: Fixing broken links to CTAS and Explain Commands
Date Fri, 28 Sep 2018 21:05:53 GMT
bbevens closed pull request #1474: DRILL-6749:  Fixing broken links to CTAS and Explain Commands
URL: https://github.com/apache/drill/pull/1474
 
 
   

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diff --git a/_docs/performance-tuning/026-parquet-filter-pushdown.md b/_docs/performance-tuning/026-parquet-filter-pushdown.md
index 466f0830a85..0afdcee561f 100644
--- a/_docs/performance-tuning/026-parquet-filter-pushdown.md
+++ b/_docs/performance-tuning/026-parquet-filter-pushdown.md
@@ -24,7 +24,7 @@ Parquet filter pushdown is similar to partition pruning in that it reduces
the a
 The query planner looks at the minimum and maximum values in each row group for an intersection.
If no intersection exists, the planner can prune the row group in the table. If the minimum
and maximum value range is too large, Drill does not apply Parquet filter pushdown. The query
planner can typically prune more data when the tables in the Parquet file are sorted by row
groups.  
 
 ##Using Parquet Filter Pushdown
-Currently, Parquet filter pushdown only supports filters that reference columns from a single
table (local filters). Parquet filter pushdown requires the minimum and maximum values in
the Parquet file metadata. All Parquet files created in Drill using the CTAS statement contain
the necessary metadata. If your Parquet files were created using another tool, you may need
to use Drill to read and rewrite the files using the [CTAS command]({{site.baseurl}}/docs/create-table-as-ctas-command/).
+Currently, Parquet filter pushdown only supports filters that reference columns from a single
table (local filters). Parquet filter pushdown requires the minimum and maximum values in
the Parquet file metadata. All Parquet files created in Drill using the CTAS statement contain
the necessary metadata. If your Parquet files were created using another tool, you may need
to use Drill to read and rewrite the files using the [CTAS command]({{site.baseurl}}/docs/create-table-as-ctas/).
  
 Parquet filter pushdown works best if you presort the data. You do not have to sort the entire
data set at once. You can sort a subset of the data set, sort another subset, and so on. 
 
@@ -39,7 +39,7 @@ The following table lists the Parquet filter pushdown options with their
descrip
 | "planner.store.parquet.rowgroup.filter.pushdown.threshold" | Sets the number of row groups
that a table can   have. You can increase the threshold if the filter can prune many row groups.
  However, if this setting is too high, the filter evaluation overhead   increases. Base this
setting on the data set. Reduce this setting if the   planning time is significant, or you
do not see any benefit at runtime. | 10,000    |  
 
 ###Viewing the Query Plan
-Because Drill applies Parquet filter pushdown during the query planning phase, you can view
the query execution plan to see if Drill pushes down the filter when a query on a Parquet
file contains a filter expression. You can run the [EXPLAIN PLAN command]({{site.baseurl}}/docs/explain-commands/)
to see the execution plan for the query, as shown in the following example.
+Because Drill applies Parquet filter pushdown during the query planning phase, you can view
the query execution plan to see if Drill pushes down the filter when a query on a Parquet
file contains a filter expression. You can run the [EXPLAIN PLAN command]({{site.baseurl}}/docs/explain/)
to see the execution plan for the query, as shown in the following example.
 
 **Example**  
 
@@ -79,4 +79,4 @@ The following table lists the supported and unsupported clauses, operators,
data
 - a dynamic star in the sub-query or queries that include the WITH statement.  
 - several filter predicates with the OR logical operator.  
 - more than one EXISTS operator (instead of JOIN operators).  
-- INNER JOIN and local filtering with a several conditions.      
\ No newline at end of file
+- INNER JOIN and local filtering with a several conditions.      


 

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