GitHub user nongli opened a pull request:
https://github.com/apache/spark/pull/9801
[SPARK-11787] [SQL] Improve Parquet scan performance when using flat
schemas.
This patch adds an alternate to the ParquetRecordReader from the parquet-mr
project
that is much faster for flat schemas. Instead of using the general
converter mechanism
from parquet-mr, this directly uses the lower level APIs from
parquet-columnar and a
customer RecordReader that directly assembles into UnsafeRows.
This is optionally disabled and only used for supported schemas.
Using a benchmark that just sums columns reading from a 1SF TPCDS
store_sales table,
I measured the rates of the entire query:
For 1 Column:
Before: 11.3M rows/second
After: 18.2M rows/second
For 2 Columns:
Before: 7.2M rows/second
After: 11.2M rows/second
For 5 Columns:
Before: 2.9M rows/second
After: 4.5M rows/second
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/nongli/spark parquet_perf
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/spark/pull/9801.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 #9801
----
commit b6a3b62bb32b414c5243e640c69a5482da78bfd6
Author: Nong Li <[email protected]>
Date: 2015-11-13T01:27:12Z
[SPARK-11787] [SQL] Improve Parquet scan performance when using flat
schemas.
This patch adds an alternate to the Parquet RecordReader from the
parquet-mr project
that is much faster for flat schemas. Instead of using the general
converter mechanism
from parquet-mr, this directly uses the lower level APIs from
parquet-columnar and a
customer RecordReader that directly assembles into UnsafeRows.
This is optionally disabled and only used for supported schemas.
Using a benchmark that just sums columns reading from a 1SF TPCDS
store_sales table,
I measured the rates of the entire query:
For 1 Column:
Before: 11.3M rows/second
After: 18.2M rows/second
For 2 Columns:
Before: 7.2M rows/second
After: 11.2M rows/second
For 5 Columns:
Before: 2.9M rows/second
After: 4.5M rows/second
----
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