[jira] [Commented] (PHOENIX-1016) Support MINVALUE, MAXVALUE, and CYCLE options in CREATE SEQUENCE

["Thomas D'Silva (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/PHOENIX-1016?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14055744#comment-14055744 ] 

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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