Greg Rahn has posted comments on this change. Change subject: IMPALA-1659: Netezza compatibility functions: metadata ......................................................................
Patch Set 1: > And what happens if schemas are disabled? > > I think I found the relevant docs: > > https://www.ibm.com/support/knowledgecenter/SSULQD_7.2.1/com.ibm.nz.adm.doc/c_sysadm_netezza_db_schema_overview.html > > If I understand correctly, schemas have to be enabled explicitly, > otherwise there is one schema corresponding to each user. > > "In previous releases [relative to 7.0.3], the Netezza system > supported one default schema per database. The default and only > schema matched the name of the database user who created the > database. [...] For Netezza systems running release 7.0.3 or later, > you can configure the system to support schemas within a database." > > Since Impala doesn't have a concept of schemas (as far as I know), > I still think that returning the user name provides the best > Netezza-compatibility here. Without schemas enabled, there is only a single namespace - the database that was specified on the connection, and there is no way to change namespaces (databases) without reconnecting. This is not the case with Impala. The USE command lets one > And what happens if schemas are disabled? > > I think I found the relevant docs: > > https://www.ibm.com/support/knowledgecenter/SSULQD_7.2.1/com.ibm.nz.adm.doc/c_sysadm_netezza_db_schema_overview.html > > If I understand correctly, schemas have to be enabled explicitly, > otherwise there is one schema corresponding to each user. > > "In previous releases [relative to 7.0.3], the Netezza system > supported one default schema per database. The default and only > schema matched the name of the database user who created the > database. [...] For Netezza systems running release 7.0.3 or later, > you can configure the system to support schemas within a database." > > Since Impala doesn't have a concept of schemas (as far as I know), > I still think that returning the user name provides the best > Netezza-compatibility here. The problem here is not simply Netezza-compatibility, it is also ANSI compatibility as those functions do have standard meanings per the spec. My recommendation would be to skip non-obvious implementations (like CURRENT_SCHEMA) for now until we can discuss further. -- To view, visit http://gerrit.cloudera.org:8080/4063 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: comment Gerrit-Change-Id: I9b5d1009bbf42acc175a942d2df484e1c64822ca Gerrit-PatchSet: 1 Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-Owner: Zoltan Ivanfi <[email protected]> Gerrit-Reviewer: Greg Rahn Gerrit-Reviewer: Marcel Kornacker <[email protected]> Gerrit-Reviewer: Tim Armstrong <[email protected]> Gerrit-Reviewer: Zoltan Ivanfi <[email protected]> Gerrit-HasComments: No
