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https://issues.apache.org/jira/browse/HBASE-17257?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15738807#comment-15738807
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Daniel Vimont commented on HBASE-17257:
---------------------------------------
Okay, when I Google about for "hbase review board", two different RB
implementations come up: one hosted by Apache (review.apache.org), the other by
Cloudera (review.cloudera.org). I'm starting out presuming that we're using the
Apache-hosted one. My Apache account that already exists for logging into this
JIRA system does not work for getting me into review.apache.org, so I created a
new account to get in.
Curious item: when I Googled for "how to post to hbase review board", the first
link that came up was by a certain "Ted Yu" who was running into trouble (back
in 2010) getting logged into Review Board and posting a diff file:
http://grokbase.com/t/hbase/dev/10c5bdz188/putting-patch-up-on-review-board
Anyway, using my new account to get into review.apache.org, I selected "New
Review Request", and in the "New Review Request for Pending Change" pane I
uploaded my patch, whereupon the web UI asked me "What is the base directory
for this diff?". Supposing the correct answer to this was the relative
directory within the project in which I generated the patch, I entered
"/hbase". Then I receive the error, "The specified diff file could not be
parsed. Line 43: No valid separator after the filename was found in the diff
header".
So, must I manually alter the patch header to make it acceptable to RB? Or do I
need to use some other git function to generate a differently formatted "diff"
file? Or something else altogether?
BTW, after I get this all sorted out, I will definitely create a new JIRA entry
for inserting basic info about the existence and usage of RB into the HBase
Reference Guide!
> Add column-aliasing capability to hbase-client
> ----------------------------------------------
>
> Key: HBASE-17257
> URL: https://issues.apache.org/jira/browse/HBASE-17257
> Project: HBase
> Issue Type: New Feature
> Components: Client
> Affects Versions: 2.0.0
> Reporter: Daniel Vimont
> Assignee: Daniel Vimont
> Labels: features
> Attachments: HBASE-17257-v2.patch, HBASE-17257-v3.patch,
> HBASE-17257.patch
>
>
> Column aliasing will provide the option for a 1, 2, or 4 byte alias value to
> be stored in each cell of an "alias enabled" column-family, in place of the
> full-length column-qualifier. Aliasing is intended to operate completely
> invisibly to the end-user developer, with absolutely no "awareness" of
> aliasing required to be coded into a front-end application. No new public
> hbase-client interfaces are to be introduced, and only a few new public
> methods should need to be added to existing interfaces, primarily to allow an
> administrator to designate that a new column-family is to be alias-enabled by
> setting its aliasSize attribute to 1, 2, or 4.
> To facilitate such functionality, new subclasses of HTable,
> BufferedMutatorImpl, and HTableMultiplexer are to be provided. The overriding
> methods of these new subclasses will invoke methods of the new AliasManager
> class to facilitate qualifier-to-alias conversions (for user-submitted Gets,
> Scans, and Mutations) and alias-to-qualifier conversions (for Results
> returned from HBase) for any Table that has one or more alias-enabled column
> families. All conversion logic will be encapsulated in the new AliasManager
> class, and all qualifier-to-alias mappings will be persisted in a new
> aliasMappingTable in a new, reserved namespace.
> An informal polling of HBase users at HBaseCon East and at the
> Strata/Hadoop-World conference in Sept. 2016 showed that Column Aliasing
> could be a popular enhancement to standard HBase functionality, due to the
> fact that full column-qualifiers are stored in each cell, and reducing this
> qualifier storage requirement down to 1, 2, or 4 bytes per cell could prove
> beneficial in terms of reduced storage and bandwidth needs. Aliasing is
> intended chiefly for column-families which are of the "narrow and tall"
> variety (i.e., that are designed to use relatively few distinct
> column-qualifiers throughout a large number of rows, throughout the lifespan
> of the column-family). A column-family that is set up with an alias-size of 1
> byte can contain up to 255 unique column-qualifiers; a 2 byte alias-size
> allows for up to 65,535 unique column-qualifiers; and a 4 byte alias-size
> allows for up to 4,294,967,295 unique column-qualifiers.
> Fuller specifications will be entered into the comments section below. Note
> that it may well not be viable to add aliasing support in the new "async"
> classes that appear to be currently under development.
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