Sybase to Oracle Stored Procedure migration Help

Question

Hello,
There is a Stored Procedure in Sybase and needs to be migrated to Oracle 10g. I need some quick help in creating temporary table and store the result set temporary. Here's the script.
Select distinct WC_POSITION_D.WID,
WC_POSITION_D.POSITION_NAME,
          WC_POSITION_D.CURR_MTH_CAPACITY,
WC_POSITION_D.NEXT_MTH_CAPACITY into #capcity
from WC_POSITION_D
***********Below SQL extract no.of skills per position for the currentMonth Active ********************
select WC_POSN_SKILL_F.POSN_WID,
count(WC_POSN_SKILL_F.SKILL_WID) as curr_skills into #currskills
from WC_POSN_SKILL_F
where WC_POSN_SKILL_F.Flag = 'A'
group by WC_POSN_SKILL_F.POSN_WID
***********Below SQL extract no.of skills per position for the NextMonth Active ********************
select WC_POSN_SKILL_F.POSN_WID,
count(WC_POSN_SKILL_F.SKILL_WID) as next_skills into #nextskills
from WC_POSN_SKILL_F
group by WC_POSN_SKILL_F.POSN_WID
***********Below SQL calculates CURR_MNTH_DMD,NEXT_MNTH_EXP_DMD per position ********************
select #capacity.WID,
((#capacity.CURR_MTH_CAPACITY)/curr_skills) as CURR_MTH_DMD,
     ((#capacity.NEXT_MTH_CAPACITY)/next_skills) as NEXT_MTH_DMD into #demand
from #capacity, #skills
where #capacity.WID = #skills.POSN_WID
***********Below statement populate CURR_MNTH_DMD,NEXT_MNTH_EXP_DMD in WC_POSN_SKILL_F ********************
UPDATE WC_POSN_SKILL_F
set WC_POSN_SKILL_F.CURR_MNTH_DMD = #demand.CURR_MTH_DMD, WC_POSN_SKILL_F.NEXT_MNTH_EXP_DMD = #demand.NEXT_MTH_DMD
from WC_POSN_SKILL_F,#demand
where WC_POSN_SKILL_F.POSN_WID = #demand.WID
any kind of immediate help/input appreciated.

Answer 1

Be careful porting code like this directly. Reason:
The reasons for using Temporary Tables in Sybase is invalid in Oracle.
In Sybase one needs to minimize locks and lock contention and escalation. This is done using temporary tables. Your Sybase script is typical of this approach - which is valid in Sybase.
However, this is not valid in Oracle. Oracle is at its core designed very differently from Sybase. A single lock in Oracle has the same overheads as a million locks - none. In Oracle, readers-of-data cannot block writers-of-data and vice versa. In Oracle there is no lock escalation - ever. This concept/problem does not exist. Period.
Porting your Sybase code to Oracle will be an attempt at using Oracle as a Sybase. Oracle is a very poor Sybase.
I urge you not to do a direct port. You will become very frustrated with Oracle. You will conclude that Oracle sucks. Use Oracle as it has been designed.. or IMO, bluntly put, do not use it all.