How to find the partition

Question

Guys,
Please can you tell me how to find the partition name from the table for say today ("SYSDATE") assuming that the table is partitioned by Date ( monthly )
ie,
I need to find the partition belonging to the current month, on which i am working
Thanks
G

Answer 1

Based on martina's suggestion (can be of course improved, maxvalue should be handled as well):
SQL> create table p(id number,time_stamp date)
  2  partition by range(time_stamp)
  3  (
  4   partition p1 values less than(date '2007-10-01'),
  5   partition p2 values less than(date '2007-11-01'),
  6   partition p3 values less than(date '2007-12-01'),
  7   partition p4 values less than(date '2008-01-01'),
  8   partition p5 values less than(date '2008-02-01'),
  9   partition p6 values less than(date '2008-03-01')
10  )
11  /
Table created.
SQL> create or replace function date_from_long(p_tabname  varchar2,
  2                                            p_partname varchar2)
  3    return date is
  4    l_long long;
  5    l_date date;
  6  begin
  7    select high_value
  8      into l_long
  9      from user_tab_partitions
10     where table_name = p_tabname
11       and partition_name = p_partname;
12    if substr(l_long, 1, 7) = 'TO_DATE' then
13      execute immediate 'select ' || l_long || ' from dual'
14        into l_date;
15      return l_date;
16    else
17      return null;
18    end if;
19  end;
20  /
Function created.
SQL> select table_name,partition_name,
  2  date_from_long(table_name,partition_name) high_value
  3  from user_tab_partitions
  4  where table_name='P'
  5  order by 3
  6  /
TABLE_NAME                     PARTITION_NAME                 HIGH_VALUE
P                              P1                             01.10.2007 00:00:00
P                              P2                             01.11.2007 00:00:00
P                              P3                             01.12.2007 00:00:00
P                              P4                             01.01.2008 00:00:00
P                              P5                             01.02.2008 00:00:00
P                              P6                             01.03.2008 00:00:00
6 rows selected.
SQL> select
  2  max(partition_name)
  3  keep
  4  (dense_rank first order by date_from_long(table_name,partition_name)) part_name
  5  from user_tab_partitions
  6  where table_name='P' and date_from_long(table_name,partition_name)>=sysdate
  7  /
PART_NAME
P2Best regards
Maxim