Hi Bernard In the execution plan it shows this: | 4 | PARTITION RANGE ITERATOR| | | | | KEY | KEY | |* 5 | TABLE ACCESS FULL | TUH_NVPAGINA | 5992K| 211M| 27159 | KEY | KEY | Since in the parse time the partition key cannot be determined we see the KEY words. I think it basically means tabla access full by partition. On 1/31/07, Polarski, Bernard <Bernard.Polarski@xxxxxxxxxxxxxx> wrote:
Still I don't understand why we have a PARTITION RAND followed by a full table scan. Why not a direct full table scan, what is the advantage of this construct > 4 2 PARTITION RANGE (ITERATOR) > 5 4 TABLE ACCESS (FULL) OF 'TUH_NVPAGINA' (Cost=27159 " On 1/30/07, *LS Cheng* < exriscer@xxxxxxxxx> wrote: TUD_FEDIA is accessed first then from that it eliminates partitions (partition start/stop KEY), the problem seems nested loop, how many rows is TU_FEDIA returning? " I don't see the keyword(stop key) in the plan. I read this plan and its only speak of a partition range access that leads to a full table scan. My only explanation is that the CBO is underlining a failed partition pruning. *Bernard Polarski* ------------------------------ *From:* amonte [mailto:ax.mount@xxxxxxxxx] *Sent:* woensdag 31 januari 2007 10:09 *To:* oracle-l@xxxxxxxxxxxxx *Subject:* Re: a explain plan question You are correct, the NL is not good, I changed to hash join and the query runs in 50 minutes. Thanks Alex On 1/30/07, *LS Cheng* < exriscer@xxxxxxxxx> wrote: doesnt look very good plan TUD_FEDIA is accessed first then from that it eliminates partitions (partition start/stop KEY), the problem seems nested loop, how many rows is TU_FEDIA returning? On 1/30/07, *Remigiusz Soko?owski* < rems@xxxxxxxx> wrote: > > Execution Plan > ---------------------------------------------------------- > 0 SELECT STATEMENT Optimizer=CHOOSE (Cost=1022392 Card=934 > Bytes=49502) > 1 0 SORT (GROUP BY) (Cost=1022392 Card=934 Bytes=49502) > 2 1 NESTED LOOPS (Cost=814767 Card=182275095 Bytes=9660580035) > 3 2 TABLE ACCESS (FULL) OF 'TUD_FEDIA' (Cost=3 Card=30 > Bytes=480) > 4 2 PARTITION RANGE (ITERATOR) > 5 4 TABLE ACCESS (FULL) OF 'TUH_NVPAGINA' (Cost=27159 > Card=5992606 Bytes=221726422) > > I was wondering how to read this plan, the order of steps. From old > set autotrace trace exp it seems to me that step 5 is the first step? > > 5 4 TABLE ACCESS (FULL) OF 'TUH_NVPAGINA' (Cost=27159 > Card=5992606 Bytes=221726422) > AFAIK the first most nested line is the first line (in this example the one indicated by You) Regards Remigiusz -- --------------------------------------- Remigiusz Sokolowski <rems@xxxxxxxx > WP/PTI/DIP/ZAB (+04858) 52 15 770 MySQL v. 4.x Oracle v. 10.x --------------------------------------- -- //www.freelists.org/webpage/oracle-l