Partitioning

От:

Abu Mushayeed <abumushayeed@yahoo.com>

Дата:

30 января 2007 г. в 02:49:08

I have partitioned a table based on period (e.g., cdate >= '2007-01-01'::date and cdate<=.2007-03-31':;date).

Now, I am issuing query like cdate >= CURRENT_DATE - 1 and cdate <= CURRENT_DATE, it scans all the partitions. But if I do cdate >= '2007-01-01'::date and cdate<=.2007-03-31'::date it picks the correct partition. Also if I join the cdate field with another table, it does not pick the correct partition.

I would like to know if it is possible to pick the correct partition using the above example.

Thanks
Abu

Need Mail bonding?
Go to the Yahoo! Mail Q&A for great tips from Yahoo! Answers users.

Re: Partitioning

От:

Rigmor Ukuhe <rigmor.ukuhe@finestmedia.ee>

Дата:

30 января 2007 г. в 06:21:46

Abu Mushayeed wrote:
> I have partitioned a table based on period (e.g., cdate >= 
> '2007-01-01'::date and cdate<=.2007-03-31':;date).
> 
> Now, I am issuing query like cdate >= CURRENT_DATE - 1 and cdate <= 
> CURRENT_DATE, it scans all the partitions. But if I do cdate >= 
> '2007-01-01'::date and cdate<=.2007-03-31'::date it picks the correct 
> partition. Also if I join the cdate field with another table, it does 
> not pick the correct partition.
> 
> I would like to know if it is possible to pick the correct partition 
> using the above example.

from http://www.postgresql.org/docs/8.1/interactive/ddl-partitioning.html

..."For the same reason, "stable" functions such as CURRENT_DATE must be 
avoided. Joining the partition key to a column of another table will not be 
optimized, either."...


Rigmor

> 
> Thanks
> Abu
> 
> ------------------------------------------------------------------------
> Need Mail bonding?
> Go to the Yahoo! Mail Q&A 
>  
> for great tips from Yahoo! Answers 
>  
> users. !DSPAM:5,45beea6d287779832115503!


-- 
Rigmor Ukuhe
Finestmedia Ltd | Software Development Team Manager
gsm : (+372)56467729 | tel : (+372)6558043 | e-mail : rigmor.ukuhe@finestmedia.ee