Table valued function in Oracle - sql-server

Question

I have used the functions in SQL Server for a long time. The functions can be used in the FROM clause and the WHERE clause can be specified.
In SQL Server the WHERE clause is used within the function itself. Unlike Oracle, the WHERE clause is applied after the function has produced the results.
The difference is important if the function without WHERE returns many results.
Furthermore, in SQL Server the indices inside the function are used if the WHERE is applied on the column with the index.
Example:
CREATE TABLE table_test (
col1 varchar(50),
col2 varchar(50)
)
--INSERT TEST DATA
Declare #Id int
Set #Id = 1
While #Id <= 1000000
Begin
Insert Into table_test values ('col1' + CAST(#Id as nvarchar(10)), 'col2' + CAST(#Id as nvarchar(10)))
Set #Id = #Id + 1
End
CREATE FUNCTION func_test() RETURNS TABLE
AS
RETURN
(
SELECT * FROM table_test
)
GO
CREATE NONCLUSTERED INDEX ixd_test ON table_test (col1) INCLUDE (col2)
SELECT * FROM func_test() WHERE col1 like 'col132%'
Is there a similar type of function in Oracle?

Answer 1

Create table
CREATE TABLE table_test (
col1 varchar(50),
col2 varchar(50)
)
Once you fill the data in to test_table (using something like follows)
Begin
for i in 1..1000000 loop
Insert Into table_test values ('col1' || TO_CHAR(i), 'col2' || TO_CHAR(i));
end loop;
commit;
End;
/
Something like follows may work. (Tested using oracle live sql)
-- Create row definition
create OR REPLACE TYPE SOME_ROW_TYPE AS OBJECT
(
COL1 varchar2(50),
COL2 varchar2(50)
)
/
-- Create table definition
create type SOME_TABLE_TYPE as table of SOME_ROW_TYPE
/
CREATE OR REPLACE FUNCTION DoStuff RETURN SOME_TABLE_TYPE AS
-- Declarations
RET_TABLE SOME_TABLE_TYPE := SOME_TABLE_TYPE();
CURSOR DATA_FETCH IS
SELECT
COL1,
COL2
FROM TABLE_TEST;
BEGIN
FOR ITEM IN DATA_FETCH LOOP
RET_TABLE.extend;
RET_TABLE(RET_TABLE.LAST) := SOME_ROW_TYPE(
ITEM.COL1,
ITEM.COL2);
END LOOP;
RETURN RET_TABLE;
END;
/
Creating index
CREATE INDEX index_name ON table_test(col1)
fetch via
select * from DoStuff() WHERE col1 like 'col132%'