On Tue, Feb 15, 2011 at 8:24 AM, Heikki Linnakangas < heikki.linnakan...@enterprisedb.com> wrote:
> On 11.02.2011 22:44, Gurjeet Singh wrote: > >> Looks like the function get_actual_variable_range() was written with the >> knowledge that virtual/hypothetical indexes may exist, but the assumption >> seems wrong. >> >> One one hand get_actual_variable_range() expects that virtual indexes do >> not >> have an OID assigned, on the other hand explain_get_index_name_hook() is >> handed just an index's OID to get its name back; IMHO these are based on >> two >> conflicting assumptions about whether a virtual index will have an OID >> assigned. >> >> Attached patch fix_get_actual_variable_range.patch tries to fix this by >> introducing a new hook that can help Postgres decide if an index is >> fictitious or not. >> > > The new hook takes an index oid as argument, so I gather that you resolved > the contradiction by deciding that fictitious indexes have OIDs. How do you > assign those OIDs? Do fictitious indexes have entries in > pg_index?<http://www.enterprisedb.com> No, a fictitious index does not touch pg_index. The Index Advisor uses GetNewOid(pg_class) to generate a new OID for the fictitious index. An OID is the only way we can identify one fictitious index from the list of all the others fictitious ones when explain_get_index_name_hook() is called. I don't see any other way the Postgres server can ask the for the details of a fictitious index. Regards, -- gurjeet.singh @ EnterpriseDB - The Enterprise Postgres Company http://www.EnterpriseDB.com singh.gurjeet@{ gmail | yahoo }.com Twitter/Skype: singh_gurjeet Mail sent from my BlackLaptop device
