On Thu, Jul 7, 2011 at 3:21 PM, Noah Misch <noah@2ndquadrant.com> wrote:
> On Thu, Jul 07, 2011 at 03:06:46PM -0400, Robert Haas wrote:
>> On Thu, Jul 7, 2011 at 2:55 PM, Noah Misch <noah@2ndquadrant.com> wrote:
>> > CheckIndexCompatible() calls ComputeIndexAttrs() to resolve the new operator
>> > classes, collations and exclusion operators for each index column. It then
>> > checks those against the existing values for the same. I figured that was
>> > obvious enough, but do you want a new version noting that?
>>
>> I guess one question I had was... are we depending on the fact that
>> ComputeIndexAttrs() performs a bunch of internal sanity checks? Or
>> are we just expecting those to always pass, and we're going to examine
>> the outputs after the fact?
>
> Those checks can fail; consider an explicit operator class or collation that
> does not support the destination type. At that stage, we neither rely on those
> checks nor mind if they do fire. If we somehow miss the problem at that stage,
> DefineIndex() will detect it later. Likewise, if we hit an error in
> CheckIndexCompatible(), we would also hit it later in DefineIndex().
OK.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company