2009/7/9 Tom Lane :
> =?UTF-8?Q?Grzegorz_Ja=C5=9Bkiewicz?= writes:
>> On Thu, Jul 9, 2009 at 5:26 PM, Craig James
>> wrote:
>>> Suppose I have a large table with a small-cardinality CATEGORY column (say,
>>> categories 1..5). I need to sort by an arbitrary (i.e. user-specified)
>>> mapping of CA
> On Thu, Jul 09, 2009 at 09:26:42AM -0700, Craig James wrote:
> You can do it like this:
> select c.*
> from categories c, ( values (1, 'z'), (2, 'a'), (3, 'b'), (4, 'w'),
(5,
> 'h') ) as o (id, ordering) on c.id = o.id
> order by o.ordering
Another option would be:
select c.*
from categories c
On Thu, Jul 09, 2009 at 09:26:42AM -0700, Craig James wrote:
> Suppose I have a large table with a small-cardinality CATEGORY column (say,
> categories 1..5). I need to sort by an arbitrary (i.e. user-specified)
> mapping of CATEGORY, something like this:
>
> 1 => 'z'
> 2 => 'a'
> 3 => 'b'
>
> From: pgsql-performance-ow...@postgresql.org
[mailto:pgsql-performance-
> ow...@postgresql.org] On Behalf Of Robin Houston
> Sent: Thursday, July 09, 2009 12:35 PM
> We have a query that runs very slowly on our 8.3 database. (I can't
> tell you exactly how slowly, because it has never successful
I noticed a bit of a performance regression in embedded sql queries when
moving from the client libraries in verison 8.2.4 to 8.3.7. My
application does a whole lot of queries, many of which don't return any
data. When we moved to the new libraries the time of running a query
(from the applicati
Robin Houston writes:
> We have a query that runs very slowly on our 8.3 database. (I can't
> tell you exactly how slowly, because it has never successfully run to
> completion even when we left it running overnight.) On the 8.4
> database on my laptop, it runs in about 90 seconds. Of course there
Robin Houston escribió:
> We have a query that runs very slowly on our 8.3 database. (I can't
> tell you exactly how slowly, because it has never successfully run to
> completion even when we left it running overnight.) On the 8.4
> database on my laptop, it runs in about 90 seconds. Of course the
On Thu, Jul 9, 2009 at 6:26 PM, Craig James wrote:
> Suppose I have a large table with a small-cardinality CATEGORY column (say,
> categories 1..5). I need to sort by an arbitrary (i.e. user-specified)
> mapping of CATEGORY, something like this:
>
> 1 => 'z'
> 2 => 'a'
> 3 => 'b'
> 4 => 'w'
>
Craig James wrote:
> Suppose I have a large table with a small-cardinality CATEGORY
> column (say, categories 1..5). I need to sort by an arbitrary
> (i.e. user-specified) mapping of CATEGORY
There was a recent thread discussing ways to do that:
http://archives.postgresql.org/pgsql-admin/200
=?UTF-8?Q?Grzegorz_Ja=C5=9Bkiewicz?= writes:
> On Thu, Jul 9, 2009 at 5:26 PM, Craig James wrote:
>> Suppose I have a large table with a small-cardinality CATEGORY column (say,
>> categories 1..5). Â I need to sort by an arbitrary (i.e. user-specified)
>> mapping of CATEGORY, something like this:
[ Attempting to resend, because it didn't seem to get through last time. ]
We have a query that runs very slowly on our 8.3 database. (I can't
tell you exactly how slowly, because it has never successfully run to
completion even when we left it running overnight.) On the 8.4
database on my laptop,
On Thu, Jul 9, 2009 at 5:26 PM, Craig James wrote:
> Suppose I have a large table with a small-cardinality CATEGORY column (say,
> categories 1..5). I need to sort by an arbitrary (i.e. user-specified)
> mapping of CATEGORY, something like this:
>
> 1 => 'z'
> 2 => 'a'
> 3 => 'b'
> 4 => 'w'
>
Suppose I have a large table with a small-cardinality CATEGORY column (say,
categories 1..5). I need to sort by an arbitrary (i.e. user-specified) mapping
of CATEGORY, something like this:
1 => 'z'
2 => 'a'
3 => 'b'
4 => 'w'
5 => 'h'
So when I get done, the sort order should be 2,3,5,4,1
Martin Chlupac wrote:
Hello everybody,
I have a simple query which selects data from not very large table (
434161 rows) and takes far more time than I'd expect. I believe it's
due to a poor disk performance because when I execute the very same
query for a second time I get much better results (c
Hello everybody,
I have a simple query which selects data from not very large table (
434161 rows) and takes far more time than I'd expect. I believe it's
due to a poor disk performance because when I execute the very same
query for a second time I get much better results (caching kicks in?).
Can y
15 matches
Mail list logo
