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https://issues.apache.org/jira/browse/PHOENIX-1016?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14055744#comment-14055744
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Thomas D'Silva commented on PHOENIX-1016:
-----------------------------------------
James,
I have attached a patch for the master/4.0 and 3.0 branches. My implementation
is consistent with how sequences work in
http://msdn.microsoft.com/en-us/library/ff878091.aspx .
The default for MINVALUE, MAXVALUE and CYCLE are Long.MIN_VALUE, Long.MAX_VALUE
and false. The default for START WITH is Long.MIN_VALUE.
This is not compatible with existing behavior since the default START WITH
value is 1, and the default behavior is to cycle.
I had to change the implementation of Sequence to store the CURRENT_VALUE in
SYSTEM.SEQUENCE (instead of NEXT_VALUE) in order to get cycle to work
correctly.
This change is not compatible with existing sequences in SYSTEM.SEQUENCE.
I am not sure how to handle these compatibility differences. Please let me know
if I need to make changes.
Thank you,
Thomas
> Support MINVALUE, MAXVALUE, and CYCLE options in CREATE SEQUENCE
> ----------------------------------------------------------------
>
> Key: PHOENIX-1016
> URL: https://issues.apache.org/jira/browse/PHOENIX-1016
> Project: Phoenix
> Issue Type: Bug
> Reporter: James Taylor
> Assignee: Thomas D'Silva
> Attachments: PHOENIX-1016.3.0.patch, PHOENIX-1016.patch
>
>
> We currently don't support MINVALUE, MAXVALUE, and CYCLE options in CREATE
> SEQUENCE, but we should. See
> http://msdn.microsoft.com/en-us/library/ff878091.aspx for the syntax.
> I believe MINVALUE applies if the INCREMENT is negative while MAXVALUE
> applies otherwise. If the value of a sequence goes beyond MINVALUE/MAXVALUE,
> then:
> - if CYCLE is true, then the sequence value should start again at the START
> WITH value (or the MINVALUE if specified too? Not sure about this).
> - if CYCLE is false, then an exception should be thrown.
> To implement this:
> - make the grammar changes in PhoenixSQL.g
> - add member variables for MINVALUE, MAXVALUE, and CYCLE to
> CreateSequenceStatement
> - add the appropriate error checking and handle bind variables for these new
> options in CreateSequenceCompiler
> - modify the MetaDataClient.createSequence() call by passing along these new
> parameters.
> - same for ConnectionQueryServices.createSequence() call
> - same for Sequence.createSequence().
> - pass along these parameters as new KeyValues in the Append that constitutes
> the RPC call
> - act on these in the SequenceRegionObserver coprocessor as indicated above.
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