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https://issues.apache.org/jira/browse/PHOENIX-4552?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16336270#comment-16336270
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Stephen Petschulat commented on PHOENIX-4552:
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> There might be a middle ground, though, but I suspect there will be many edge
>cases. If we still continue to return only the single latest version and
>restrict the filtering done on ROW_TIMESTAMP to use only greater than or
>greater than or equal then it might be more feasible.
That is actually the only case that we need. We would like to specify a
timestamp and get back only most the recent row less than or equal to that
timestamp. It will allow us to upload a batch CSV file and set the timestamp
for all rows to the current timestamp. Subsequent uploads will set a newer
timestamp but any queries running against the old timestamp data (assuming they
specify it correctly) will see the old version of the CSV while the new one
uploads.
Setting VERSIONS to some reasonable number will allow old ones to get garbage
collected automatically. We just have to make sure we don't have queries that
run overly long against old versions.
> Add support for a ROW_TIMESTAMP that doesn't affect the primary key
> -------------------------------------------------------------------
>
> Key: PHOENIX-4552
> URL: https://issues.apache.org/jira/browse/PHOENIX-4552
> Project: Phoenix
> Issue Type: New Feature
> Reporter: Stephen Petschulat
> Priority: Minor
>
> By declaring a ROW_TIMESTAMP constraint on a Phoenix table, it does two
> things 1) expose the hbase native timestamp as this column and 2) prepend
> your primary key with this timestamp as well.
> It would be useful to have a similar feature that only exposes the hbase
> native timestamp. This would allow explicit setting of the timestamp when
> upserting data while allowing multiple hbase versions. It is possible to then
> query for that specific key and version(s).
> Potential approach:
> {code:sql}
> CREATE TABLE COMMENTS (
> COMMENT_ID INT NOT NULL,
> REVISION_NUM BIGINT NOT NULL ROW_TIMESTAMP, // NEW use of keyword
> COMMENT_BODY TEXT
> CONSTRAINT PK PRIMARY KEY(COMMENT_ID))
> UPSERT INTO COMMENTS (123, 1, 'edit 1 comment')
> UPSERT INTO COMMENTS (123, 2, 'edit 2 of comment')
> UPSERT INTO COMMENTS (123, 3, 'edit 3 of comment')
> {code}
>
> Current behavior of ROW_TIMESTAMP would create a new primary for each upsert,
> so querying by primary key is no longer straightforward when you don't know
> the version number at query time.
> {code:sql}
> SELECT * FROM COMMENTS WHERE COMMENT_ID = 123 // => returns most recent
> version 'edit 3 of comment'
> SELECT * FROM COMMENTS WHERE COMMENT_ID = 123 AND REVISION_NUM = 1 // =>
> returns explicit version 'edit 1 comment'
> {code}
>
> It can also be useful to return multiple versions (related: PHOENIX-590)
> {code:sql}
> SELECT * FROM COMMENTS WHERE COMMENT_ID = 123 AND REVISION_NUM < 3 // =>
> returns 2 rows
> {code}
>
> Or just the highest version less than or equal to a particular version
> (allowing snapshot queries):
> {code:sql}
> // set CurrentSCN=2 on connection
> SELECT * FROM COMMENTS WHERE COMMENT_ID = 123 // => returns 'edit 2 of
> comment'
> {code}
> CurrentSCN already allows this type of snapshot query but not against an
> explicitly set timestamp with multiple versions. The primary key injection
> prevents this. The above query would behave similar to:
> {code:java}
> scan 'COMMENTS', {TIMERANGE => [0, <maxversionid+1>]}
> {code}
> This returns the highest versioned value for each key that is less than a
> specified maximum version number.
>
>
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