GitHub user nongli opened a pull request:
https://github.com/apache/spark/pull/9774
[WIP] [SPARK-11787] [SQL] Improve Parquet scan performance when usingâ¦
⦠flat schemas.
WIP: this still needs to implement more types and some type conversion
logic.
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 the benchmark in PerfTest (I'll remove before this is ready to merge)
the rate
for the entire query changes from:
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
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/spark/pull/9774.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 #9774
----
commit 56f86c5e7ef447738c5bfd67d1a58a8c1d755f0a
Author: Nong Li <[email protected]>
Date: 2015-11-13T01:27:12Z
[WIP] [SPARK-11787] [SQL] Improve Parquet scan performance when using flat
schemas.
WIP: this still needs to implement more types and some type conversion
logic.
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 the benchmark in PerfTest (I'll remove before this is ready to merge)
the rate
for the entire query changes from:
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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