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Date: Fri, 5 Oct 2012 14:50:02 +0000 (UTC)
From: "Eric Newton (JIRA)" <jira@apache.org>
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Subject: [jira] [Commented] (ACCUMULO-786) Look into walog space usage
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    [ https://issues.apache.org/jira/browse/ACCUMULO-786?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13470363#comment-13470363 ] 

Eric Newton commented on ACCUMULO-786:
--------------------------------------

The mutation serialization code is pretty simple: lengths are encoded as 4-byte signed integers, timestamps which are normally not set by the user, are encoded as 8-byte signed longs.  There's roughly 36 bytes of overhead for an empty mutation.

We could encode the lengths and timestamps as variable-length integers.  It might not be worth the extra encoding/decoding time, though.  We'll need to experiment.
                
> Look into walog space usage
> ---------------------------
>
>                 Key: ACCUMULO-786
>                 URL: https://issues.apache.org/jira/browse/ACCUMULO-786
>             Project: Accumulo
>          Issue Type: Task
>            Reporter: Keith Turner
>             Fix For: 1.5.0
>
>
> I was experimenting with write ahead log write performance and noticed that when I wrote 1G of data that the walog was 1.5G.

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