Peter Eisentraut writes:
> On fre, 2010-11-12 at 09:44 -0500, Tom Lane wrote:
>> But I'm still not convinced that this feature is useful enough to
>> justify the implementation effort. AFAICS there's nothing here that
>> you couldn't get with some non-default operators on regular arrays,
> Uniqu
On fre, 2010-11-12 at 09:44 -0500, Tom Lane wrote:
> But I'm still not convinced that this feature is useful enough to
> justify the implementation effort. AFAICS there's nothing here that
> you couldn't get with some non-default operators on regular arrays,
Unique constraints would behave differ
David Fetter writes:
> On Mon, Nov 15, 2010 at 10:13:40AM -0500, Tom Lane wrote:
>> Itagaki Takahiro writes:
>>> Another issue for sorting is that we have 4 kinds of sorting: ASC/DESC
>>> and NULLS FIRST/LAST.
>> We have a lot more kinds than that. See USING.
> USING pretty much gives us no ch
On Mon, Nov 15, 2010 at 10:13:40AM -0500, Tom Lane wrote:
> Itagaki Takahiro writes:
> > Another issue for sorting is that we have 4 kinds of sorting: ASC/DESC
> > and NULLS FIRST/LAST.
>
> We have a lot more kinds than that. See USING.
USING pretty much gives us no chance of optimizing at all.
Itagaki Takahiro writes:
> Another issue for sorting is that we have 4 kinds of sorting: ASC/DESC
> and NULLS FIRST/LAST.
We have a lot more kinds than that. See USING.
regards, tom lane
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On Monday 15 November 2010 09:47:15 Itagaki Takahiro wrote:
> On Mon, Nov 15, 2010 at 14:37, Pavel Stehule
wrote:
> > Maybe can be useful to implement a searching on sorted array.
> > You can hold a flag if multiset is sorted or not.
>
> Are you suggesting to add an IS_SORTED bit to for each Arr
2010/11/15 Itagaki Takahiro :
> On Mon, Nov 15, 2010 at 14:37, Pavel Stehule wrote:
>> Maybe can be useful to implement a searching on sorted array.
>> You can hold a flag if multiset is sorted or not.
>
> Are you suggesting to add an IS_SORTED bit to for each ArrayType value?
> It might be possib
On Mon, Nov 15, 2010 at 14:37, Pavel Stehule wrote:
> Maybe can be useful to implement a searching on sorted array.
> You can hold a flag if multiset is sorted or not.
Are you suggesting to add an IS_SORTED bit to for each ArrayType value?
It might be possible, but I'm not sure how much it is use
Hello
2010/11/15 Itagaki Takahiro :
> On Fri, Nov 12, 2010 at 00:02, Itagaki Takahiro
> wrote:
>> Postgres supports ARRAY data types well, but there are some
>> more array functions in the SQL standard. Also, the standard
>> has MULTISET data type, that is an unordered array.
>
> Here is a WIP pa
On Fri, Nov 12, 2010 at 00:02, Itagaki Takahiro
wrote:
> Postgres supports ARRAY data types well, but there are some
> more array functions in the SQL standard. Also, the standard
> has MULTISET data type, that is an unordered array.
Here is a WIP patch for multiset function supports. Note that m
On Fri, Nov 12, 2010 at 12:53:09AM -0500, Robert Haas wrote:
> On Fri, Nov 12, 2010 at 12:21 AM, Tom Lane wrote:
> > Robert Haas writes:
> >> On Thu, Nov 11, 2010 at 10:02 AM, Itagaki Takahiro
> >> wrote:
> >>> If we reuse type IDs of arrays for multisets, the multisets would
> >>> have some spe
Robert Haas writes:
> On Fri, Nov 12, 2010 at 12:21 AM, Tom Lane wrote:
>> The problem is not with the type system: as long as you give multisets
>> different type OIDs from arrays, everything will work fine.
> And thus you must create a THIRD copy of every entry in pg_type. That
> doesn't qual
On Fri, Nov 12, 2010 at 12:21 AM, Tom Lane wrote:
> Robert Haas writes:
>> On Thu, Nov 11, 2010 at 10:02 AM, Itagaki Takahiro
>> wrote:
>>> If we reuse type IDs of arrays for multisets, the multisets would
>>> have some special typmod. For example, typmod = 0 means multiset,
>>> and positive val
Robert Haas writes:
> On Thu, Nov 11, 2010 at 10:02 AM, Itagaki Takahiro
> wrote:
>> If we reuse type IDs of arrays for multisets, the multisets would
>> have some special typmod. For example, typmod = 0 means multiset,
>> and positive value means array with max cardinality. Note that
>> the SQL
On Thu, Nov 11, 2010 at 10:02 AM, Itagaki Takahiro
wrote:
> If we reuse type IDs of arrays for multisets, the multisets would
> have some special typmod. For example, typmod = 0 means multiset,
> and positive value means array with max cardinality. Note that
> the SQL standard doesn't mention abou
On Fri, Nov 12, 2010 at 06:06, Darren Duncan wrote:
> This is one place that SQL made things more complicated than they needed to
> be. Multisets have generally the same structure *and* operators (union,
> etc) as tables, but they use different syntax for each. A better design
> would be to make
On Fri, Nov 12, 2010 at 03:05, Tom Lane wrote:
> "David E. Wheeler" writes:
>> So are you planning to implement multisets? It's a feature I'd love to see
>
> What actual functionality does it buy? AFAICT from Itagaki-san's
> description, it's an array only you ignore the specific element order.
Merlin Moncure wrote:
On Thu, Nov 11, 2010 at 3:42 PM, David E. Wheeler wrote:
On Nov 11, 2010, at 12:08 PM, Alvaro Herrera wrote:
That sounds like a composite type to me.
No, it's "perpendicular" in the sense that while a composite type allows
you to have different columns, this multiset th
On Thu, Nov 11, 2010 at 3:42 PM, David E. Wheeler wrote:
> On Nov 11, 2010, at 12:08 PM, Alvaro Herrera wrote:
>
>>> That sounds like a composite type to me.
>>
>> No, it's "perpendicular" in the sense that while a composite type allows
>> you to have different columns, this multiset thing lets yo
On Nov 11, 2010, at 12:08 PM, Alvaro Herrera wrote:
>> That sounds like a composite type to me.
>
> No, it's "perpendicular" in the sense that while a composite type allows
> you to have different columns, this multiset thing lets you have "rows"
> (I initially thought about them as sets of scala
Excerpts from David E. Wheeler's message of jue nov 11 15:45:55 -0300 2010:
> On Nov 11, 2010, at 10:19 AM, Darren Duncan wrote:
>
> > I think that it would be best to implement MULTISET in the same way that a
> > TABLE is implemented. Logically and structurally they are the same thing,
> > but
On Nov 11, 2010, at 10:24 AM, Nicolas Barbier wrote:
>> Also, no dupes.
>
> The "multi" in multiset indicates that duplicate elements are
> explicitly allowed and tracked.
D'oh! Right.
D
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On Nov 11, 2010, at 10:19 AM, Darren Duncan wrote:
> I think that it would be best to implement MULTISET in the same way that a
> TABLE is implemented. Logically and structurally they are the same thing, but
> that a MULTISET typically is used as a field value of a table row. Aka, a
> table an
2010/11/11 David E. Wheeler :
> On Nov 11, 2010, at 10:05 AM, Tom Lane wrote:
>
>>> So are you planning to implement multisets? It's a feature I'd love to see
>>
>> What actual functionality does it buy? AFAICT from Itagaki-san's
>> description, it's an array only you ignore the specific element
I think that it would be best to implement MULTISET in the same way that a TABLE
is implemented. Logically and structurally they are the same thing, but that a
MULTISET typically is used as a field value of a table row. Aka, a table and a
multiset are just different names for a relation, loose
On Nov 11, 2010, at 10:05 AM, Tom Lane wrote:
>> So are you planning to implement multisets? It's a feature I'd love to see
>
> What actual functionality does it buy? AFAICT from Itagaki-san's
> description, it's an array only you ignore the specific element order.
> So what? You can write func
"David E. Wheeler" writes:
> So are you planning to implement multisets? It's a feature I'd love to see
What actual functionality does it buy? AFAICT from Itagaki-san's
description, it's an array only you ignore the specific element order.
So what? You can write functions that work that way now
On Nov 11, 2010, at 7:02 AM, Itagaki Takahiro wrote:
> MULTISET supports are more difficult. We have corresponding
> type IDs for each array, but we might not want to add additional
> IDs for multiset for each type. Any ideas for the issue?
Why not?
> If we reuse type IDs of arrays for multisets
Postgres supports ARRAY data types well, but there are some
more array functions in the SQL standard. Also, the standard
has MULTISET data type, that is an unordered array.
It looks easy to support additional array functions. There
might be some confusion to treat multi-dimensional arrays
with the
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