PL/SQL Colelction how to use in procedure

Question

i am converting SQL Server stored procedure in oracle in which i have made use of TABLE variable but TABLE variable is not there is oracle i searched on Google instead of TABLE variable we can use of COLLECTIONS in PL/SQL
i could not find the syntax for using that i am giving you some lines please give the equivalent code for that
ALTER procedure usp_GetLLWardItemsReceived
p_ItemReceivedMstID int
as
----------declaring this first table variable @t1 --------------
Declare @t1 Table
WardItemDtl_ID int,
ItemID int,
ItemQty int,
WardID int,
WardTransID int
----------declaring this first table variable @t2 --------------
Declare @t2 Table
WardItemDtl_ID int,
ItemID int,
IssueItemQty int
----------inserting data into first table variable @t1--------------------------
insert into @t1(WardItemDtl_ID,WardTransID,ItemID,ItemQty,WardID)
select WardItemDtl_ID,WardTransID,wdDtl.ItemID
,Sum(ItemQty) ItemQty,ReceivedWardID from LL_WardItems_Details wdDtl
where isposted=0
group by wdDtl.ItemID,WardItemDtl_ID,ReceivedWardID,WardTransID
order by WardItemDtl_ID
----------inserting data into first table variable @t2--------------------------
insert into @t2(WardItemDtl_ID,ItemID,IssueItemQty)
select WardItemDtl_ID,ItemID,Sum(IssueItemQty)IssueItemQty from LL_PartyItems_Details
group by WardItemDtl_ID,ItemID order by WardItemDtl_ID
and some code here to do calculation then show to end user
please somebody helpme in this that how can i do this in PL/SQL collections or some alterntive

Answer 1

user21354 wrote:
thanks for your reply please give me some sort oh hint what or which alternative approach i can use to solve this problemPlease define the problem - it is a tad difficult to suggest an approach to a solution when the actual problem is unknown.
In general terms - there are very seldom need for temporary tables in Oracle. The feature is supported (called GTT or global temporary tables). It does not work like SQL-Server's temp table feature.
Collections in PL/SQL usually serve a single purpose only - reducing the context switching between the PL/SQL and SQL engines. A collection allows for a bigger size pipe to pass data between the two. Oppose to passing a single row at a time via a context switch.
The price for a collection is an increase is very expensive server memory called PGA. So there is a balance between reducing context switching at the expense of increased PGA consumption.
For this reason too, it is a very bad idea to use collections as an alternative to SQL tables and cache SQL data in collections. And this is essentially what your approach will result in - using PL/SQL collections like they are some kind of temporary SQL table.
You can crash the database server like that. I have seen this more than once. Oracle attempts to do as instructed (unless limits are imposed such as resource profiles). So if your PL/SQL attempts to create a 1GB size collection in PGA memory, Oracle will not tell you that it is a stupid thing to do. It will do as your code instructs - and in the process can totally exhaust every single bye of server memory. And this results in such severe swapping of memory pages between disk and RAM, that the entire server becomes unresponsive to such an extent that the sysadmin will not even be able to log into the server to correct the problem.