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https://issues.apache.org/jira/browse/HIVE-2370?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13083792#comment-13083792
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[email protected] commented on HIVE-2370:
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Great job! Does this number indicate the read and write speed or just the read
(including decompression) part?
trunk/cli/src/java/org/apache/hadoop/hive/cli/RCFileCat.java
<https://reviews.apache.org/r/1474/#comment3266>
can you remove all these TABs?
trunk/cli/src/java/org/apache/hadoop/hive/cli/RCFileCat.java
<https://reviews.apache.org/r/1474/#comment3267>
make 2048 a static constant variable.
- Ning
On 2011-08-11 22:44:48, Tim Armstrong wrote:
bq.
bq. -----------------------------------------------------------
bq. This is an automatically generated e-mail. To reply, visit:
bq. https://reviews.apache.org/r/1474/
bq. -----------------------------------------------------------
bq.
bq. (Updated 2011-08-11 22:44:48)
bq.
bq.
bq. Review request for hive, Yongqiang He, Ning Zhang, and namit jain.
bq.
bq.
bq. Summary
bq. -------
bq.
bq. This patch improves rcfilecat performance enormously: throughput increased
from 0.32MB/s to 5.15MB/s on one benchmark: 16x. There were a number of
improvements I made to get to this performance:
bq.
bq. Initial:
bq. 0.32 MB/s
bq.
bq. Change System.out to use bigger buffer (not line buffered)
bq. 1.7MB/s
bq.
bq. Unchecked Get:
bq. 1.75MB/s
bq.
bq. Use StringBuilder to construct each row before writing output.
bq. 3.7MB/s
bq.
bq. Streamline decoding:
bq. 4.16 MB/s
bq.
bq. Use StringBuilder to buffer multiple lines:
bq. 5 MB/s
bq.
bq. Tuning buffer sizes:
bq. 5.15 MB/s
bq.
bq.
bq. I also added a --verbose mode which writes progress updates to stderr.
bq.
bq.
bq. This addresses bug HIVE-2370.
bq. https://issues.apache.org/jira/browse/HIVE-2370
bq.
bq.
bq. Diffs
bq. -----
bq.
bq. trunk/cli/src/java/org/apache/hadoop/hive/cli/RCFileCat.java 1156839
bq.
bq. Diff: https://reviews.apache.org/r/1474/diff
bq.
bq.
bq. Testing
bq. -------
bq.
bq. Used diff to check output was same as old version of RCFileCat
bq.
bq.
bq. Thanks,
bq.
bq. Tim
bq.
bq.
> Improve RCFileCat performance significantly
> -------------------------------------------
>
> Key: HIVE-2370
> URL: https://issues.apache.org/jira/browse/HIVE-2370
> Project: Hive
> Issue Type: Improvement
> Components: CLI
> Affects Versions: 0.8.0
> Reporter: Tim Armstrong
> Assignee: Tim Armstrong
> Priority: Minor
> Attachments: rcfilecat_2011-08-11.patch
>
>
> The rcfilecat utility is extraordinarily slow: the throughput can be < 0.5
> MB/s of compressed RCFile. We can implement much faster version to enable
> faster export of data from Hive.
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