[
https://issues.apache.org/jira/browse/CASSANDRA-7304?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14051224#comment-14051224
]
Oded Peer commented on CASSANDRA-7304:
--------------------------------------
Having two steps can still break backwards compatibility for clients skipping
over the first step (advancing from the existing version to the step-2 version).
On second thought step 1 by itself breaks backwards compatibility by forcing
client to change their code.
I don't see an elegant way to change existing behavior without breaking
backwards compatibility.
As I see it you can either keep the existing syntax and semantics in-tact and
add new syntax for the new feature (IGNORE NULLS), or break backwards
compatibility and release this feature in a major version.
> Ability to distinguish between NULL and UNSET values in Prepared Statements
> ---------------------------------------------------------------------------
>
> Key: CASSANDRA-7304
> URL: https://issues.apache.org/jira/browse/CASSANDRA-7304
> Project: Cassandra
> Issue Type: Improvement
> Reporter: Drew Kutcharian
> Labels: cql
> Attachments: 7304.patch
>
>
> Currently Cassandra inserts tombstones when a value of a column is bound to
> NULL in a prepared statement. At higher insert rates managing all these
> tombstones becomes an unnecessary overhead. This limits the usefulness of the
> prepared statements since developers have to either create multiple prepared
> statements (each with a different combination of column names, which at times
> is just unfeasible because of the sheer number of possible combinations) or
> fall back to using regular (non-prepared) statements.
> This JIRA is here to explore the possibility of either:
> A. Have a flag on prepared statements that once set, tells Cassandra to
> ignore null columns
> or
> B. Have an "UNSET" value which makes Cassandra skip the null columns and not
> tombstone them
> Basically, in the context of a prepared statement, a null value means delete,
> but we don’t have anything that means "ignore" (besides creating a new
> prepared statement without the ignored column).
> Please refer to the original conversation on DataStax Java Driver mailing
> list for more background:
> https://groups.google.com/a/lists.datastax.com/d/topic/java-driver-user/cHE3OOSIXBU/discussion
--
This message was sent by Atlassian JIRA
(v6.2#6252)
