On 28 January 2011 20:28, Thom Brown <thom@linux.com> wrote:
> On 28 January 2011 07:45, Jeff Davis <pgsql@j-davis.com> wrote:
>> Updated patch.
>>
>> Changes:
>>
>> * Documentation for operators/functions
>> * a comprehensive set of operators and functions
>> * BTree opclass
>> * Hash opclass
>> * built-in range types:
>> - PERIOD (timestamp)
>> - PERIODTZ (timestamptz)
>> - DATERANGE (date)
>> - INTRANGE (int4)
>> - NUMRANGE (numeric)
>> * added subtype float function to the API, which will be useful for
>> GiST
>> * created canonical functions for intrange and daterange, so that:
>> '[1,5]'::intrange = '[1,6)'::intrange
>> * added length() function, written in SQL as:
>> select upper($1) - lower($1)
>> which uses polymorphic "-" operator to avoid the need to
>> give the subtype subtract function and return type to the generic
>> API
>>
>> Open items:
>>
>> * More documentation work
>> * Settle any representation/alignment concerns
>> * Should the new length() function be marked as immutable, stable,
>> or volatile? It uses the polymorphic "-" operator, and I suppose
>> someone could define a non-immutable version of that before calling
>> length(). Then again, it is likely to be inlined anyway, right?
>> * GiST
>> - docs
>> - catalog work
>> - implementation
>> * typmod support (optional)
>>
>> This is nearing completion. GiST is by far the most amount of effort
>> remaining that I'm aware of. Comments about the API, naming,
>> representation, interface, funcationality, grammar, etc. are welcome.
>>
>> Regards,
>> Jeff Davis
>
> Very nice work Jeff!
>
> This is not very graceful:
>
> postgres=# CREATE TYPE numrange AS RANGE (SUBTYPE=numeric,
> SUBTYPE_CMP=numeric_cmp);
> ERROR: duplicate key value violates unique constraint
> "pg_range_rgnsubtype_index"
> DETAIL: Key (rngsubtype)=(1700) already exists.
>
> Also, if I try the same, but with a different name for the type, I get
> the same error. Why does that restriction exist? Can't you have
> types which happen to use the exact same subtype?
Also, how do you remove a range type which coincides with a system
range type. For example:
postgres=# CREATE TYPE numrange AS RANGE (SUBTYPE=interval, SUBTYPE_CMP=interval_cmp);
CREATE TYPE
postgres=# drop type numrange;
ERROR: cannot drop type numrange because it is required by the database system
Is this because I shouldn't have been able to create this type in the
first place?
--
Thom Brown
Twitter: @darkixion
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Registered Linux user: #516935
