[ http://issues.apache.org/jira/browse/DERBY-573?page=comments#action_12329952 ]
Mamta A. Satoor commented on DERBY-573: --------------------------------------- There was discussion about various possible options to support optimizer hints in the past. One thread on this is titled "Optimizer hints?" at http://mail-archives.apache.org/mod_mbox/db-derby-dev/200412.mbox/[EMAIL PROTECTED] The other thread is titled "Join order and access path" at http://mail-archives.apache.org/mod_mbox/db-derby-dev/200502.mbox/[EMAIL PROTECTED] In the absence of SQL standard way of implementing this and based on the 2 email threads, I proposed to implement this with special comments --PROPERTIES. Also, since the time I wrote the functional spec, I have been tweaking the parser to ignore white spaces(this includes " ", "\t") between -- and PROPERTIES to make parser more flexible about how a user specifies the properties. My work in the parser to support the optimizer hints is not completely finished. Hope to make more progress in couple days. > Provider support for optimizer overrides in Derby. > -------------------------------------------------- > > Key: DERBY-573 > URL: http://issues.apache.org/jira/browse/DERBY-573 > Project: Derby > Type: New Feature > Components: SQL > Versions: 10.2.0.0 > Reporter: Mamta A. Satoor > Assignee: Mamta A. Satoor > Attachments: optimizeroverrides.html > > Derby's query optimizer usually makes the best choice of join order and > access path. The default join strategy ususally works the best too. However, > there are some cases in which user may want to override the optimizer or the > default values. Providing support for optimizer overrides will allow users to > hand-tune the optimizer for queries. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira
