[ https://issues.apache.org/jira/browse/DERBY-481?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Rick Hillegas updated DERBY-481: -------------------------------- Attachment: GeneratedColumns.html Attaching a first rev of a functional spec for this features: GeneratedColumns.html > implement SQL generated columns > ------------------------------- > > Key: DERBY-481 > URL: https://issues.apache.org/jira/browse/DERBY-481 > Project: Derby > Issue Type: New Feature > Components: SQL > Affects Versions: 10.0.2.1 > Reporter: Rick Hillegas > Attachments: GeneratedColumns.html > > > Satheesh has pointed out that generated columns, a SQL 2003 feature, would > satisfy the performance requirements of Expression Indexes (bug 455). > Generated columns may not be as elegant as Expression Indexes, but they are > easier to implement. We would allow the following new kind of column > definition in CREATE TABLE and ALTER TABLE statements: > columnName GENERATED ALWAYS AS ( expression ) > If expression were an indexableExpression (as defined in bug 455), then we > could create indexes on it. There is no work for the optimizer to do here. > The Language merely has to compute the generated column at INSERT/UPDATE time. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.