> Will this achieve the same result for garbage collection given the index ...

> We have a transactional table that looks like this:
>
> CREATE TABLE ITEMDAILYFORECAST (
> ITEMDAILYFORECASTNO INTEGER NOT NULL, /*just a unique integer*/
> ITEMNO INTEGER NOT NULL, /*a unique item*/
> FORECASTTYPENO INTEGER NOT NULL, /*a value for the type of FC e.g. 3*/
> FORECASTDATE DATE NOT NULL, /*a date for the FC value*/
> FCVALUE DOUBLE PRECISION DEFAULT 0, /*the FC value*/
> LOCATIONNO INTEGER NOT NULL, /*the location the item belongs to*/
> CONSTRAINT PK_ITEMDAILYFORECAST PRIMARY KEY (ITEMDAILYFORECASTNO)
> );
> We have the following foreign keys:
> ALTER TABLE ITEMDAILYFORECAST ADD CONSTRAINT FK_ITEMDAILYFC_FCTYPE FOREIGN
> KEY (FORECASTTYPENO) REFERENCES FORECASTTYPE(FORECASTTYPENO);
> ALTER TABLE ITEMDAILYFORECAST ADD CONSTRAINT FK_ITEMDAILYFC_ITEM FOREIGN KEY
> (ITEMNO) REFERENCES ITEM(ITEMNO);
> And a index on the location and type of FC
> CREATE INDEX IDX_LOCATION_FCTYPE ON
> ITEMDAILYFORECAST(LOCATIONNO,FORECASTTYPENO);
>
> We have a batch process that runs every night and then we delete all the
> rows for a given location and a FC type e.g.
> delete from ITEMDAILYFORECAST
> Where LOCATIONNO = 1
> and FORECASTTYPENO = 4
>
> We then want to take care of garbage and conventionally we would have done
> something like this:
> select count(*)
> from ITEMDAILYFORECAST
>
> My question is, if I run a query
> select count(*)
> from ITEMDAILYFORECAST
> Where LOCATIONNO = 1
> and FORECASTTYPENO = 4
> Will this achieve the same result for garbage collection given the index I
> have on the table?
>
> Peter Ypenburg