[jira] [Updated] (CASSANDRA-6412) Custom creation and merge functions for user-defined column types
[ https://issues.apache.org/jira/browse/CASSANDRA-6412?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] C. Scott Andreas updated CASSANDRA-6412: Component/s: Core > Custom creation and merge functions for user-defined column types > - > > Key: CASSANDRA-6412 > URL: https://issues.apache.org/jira/browse/CASSANDRA-6412 > Project: Cassandra > Issue Type: New Feature > Components: Core >Reporter: Nicolas Favre-Felix >Priority: Major > > This is a proposal for a new feature, mapping custom types to Cassandra > columns. > These types would provide a creation function and a merge function, to be > implemented in Java by the user. > This feature relates to the concept of CRDTs; the proposal is to replicate > "operations" on these types during write, to apply these operations > internally during merge (Column.reconcile), and to also merge their values on > read. > The following operations are made possible without reading back any data: > * MIN or MAX(value) for a column > * First value for a column > * Count Distinct > * HyperLogLog > * Count-Min > And any composition of these too, e.g. a Candlestick type includes first, > last, min, and max. > The merge operations exposed by these types need to be commutative; this is > the case for many functions used in analytics. > This feature is incomplete without some integration with CASSANDRA-4775 > (Counters 2.0) which provides a Read-Modify-Write implementation for > distributed counters. Integrating custom creation and merge functions with > new counters would let users implement complex CRDTs in Cassandra, including: > * Averages & related (sum of squares, standard deviation) > * Graphs > * Sets > * Custom registers (even with vector clocks) > I have a working prototype with implementations for min, max, and Candlestick > at https://github.com/acunu/cassandra/tree/crdts - I'd appreciate any > feedback on the design and interfaces. -- This message was sent by Atlassian JIRA (v7.6.3#76005) - To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org For additional commands, e-mail: commits-h...@cassandra.apache.org
[jira] [Updated] (CASSANDRA-6412) Custom creation and merge functions for user-defined column types
[ https://issues.apache.org/jira/browse/CASSANDRA-6412?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Jeff Jirsa updated CASSANDRA-6412: -- Assignee: (was: Jeff Jirsa) > Custom creation and merge functions for user-defined column types > - > > Key: CASSANDRA-6412 > URL: https://issues.apache.org/jira/browse/CASSANDRA-6412 > Project: Cassandra > Issue Type: New Feature > Components: Core >Reporter: Nicolas Favre-Felix > > This is a proposal for a new feature, mapping custom types to Cassandra > columns. > These types would provide a creation function and a merge function, to be > implemented in Java by the user. > This feature relates to the concept of CRDTs; the proposal is to replicate > "operations" on these types during write, to apply these operations > internally during merge (Column.reconcile), and to also merge their values on > read. > The following operations are made possible without reading back any data: > * MIN or MAX(value) for a column > * First value for a column > * Count Distinct > * HyperLogLog > * Count-Min > And any composition of these too, e.g. a Candlestick type includes first, > last, min, and max. > The merge operations exposed by these types need to be commutative; this is > the case for many functions used in analytics. > This feature is incomplete without some integration with CASSANDRA-4775 > (Counters 2.0) which provides a Read-Modify-Write implementation for > distributed counters. Integrating custom creation and merge functions with > new counters would let users implement complex CRDTs in Cassandra, including: > * Averages & related (sum of squares, standard deviation) > * Graphs > * Sets > * Custom registers (even with vector clocks) > I have a working prototype with implementations for min, max, and Candlestick > at https://github.com/acunu/cassandra/tree/crdts - I'd appreciate any > feedback on the design and interfaces. -- This message was sent by Atlassian JIRA (v6.3.4#6332)
