Hi Maria, I would like to know what is the use of knowing producers & consumer processes ? Also what would we do by knowing the different distribution methods ?
Hi Jamsher, I did add a video recently on why you didn't get partition pruning ua-cam.com/video/L9HB7UEeNbg/v-deo.html, which includes details on how to read a plan on a partitioned table.
Hi Jay, Yes, you can use parallel execution with index access but not all index accesses can be parallelized without partitioned indexes. For example, Fast Full Index Scan and Bitmap Index Scans can be parallelized using Block Iterators but the majority of index accesses rely on Partition Iterators to be able to parallelize the access. So, if you do an Index Range Scan, Index Skip Scan, or Index Full Scan then we can only parallelize the operation if the index is partitioned.
Hi Amrit, PCWC stands for PARALLEL COMBINED WITH CHILD. In this case, the Parent operation is Line 7 of the plan or the distribution of blocks from the LINEORDERS table among the parallel server process, i.e., the children of this operation. On line 8 of the plan, we see the parallel server processes scan those blocks and apply the where clause predicate to those scanned rows. This is the Child operation. So, lines 7 and 8 are tied together, and PCWC and PCWP in the IN-OUT column indicate which line is the Parent and which is the Child.
I am enjoying your all videos/pfd. really thank you. :)
you made learning very simple
thank you
Thanks a lot.
Hi Maria, I would like to know what is the use of knowing producers & consumer processes ? Also what would we do by knowing the different distribution methods ?
Thanks!
Hi, May I know is this technique will consume a lot cpu when query execute? is it will impact to whole system become slow?
awesome. please provide videos on performance tuning/AWR
Thanks for the insights
Hi Maria. Would be possible to have the slides you've used in this amazing explanation?
Hi Carlos, you can find the slides I used as the basis of this video at speakerdeck.com/sqlmaria/now-to-read-a-parallel-execution-plan-in-oracle
Hi Maria, Can you please make video on How to read Execution Plan on Partition Tables.
Hi Jamsher, I did add a video recently on why you didn't get partition pruning ua-cam.com/video/L9HB7UEeNbg/v-deo.html, which includes details on how to read a plan on a partitioned table.
@@SQLMaria Thanks for reply.
Ma'am, can a parallel query ever go through an index scan ?
Hi Jay, Yes, you can use parallel execution with index access but not all index accesses can be parallelized without partitioned indexes. For example, Fast Full Index Scan and Bitmap Index Scans can be parallelized using Block Iterators but the majority of index accesses rely on Partition Iterators to be able to parallelize the access. So, if you do an Index Range Scan, Index Skip Scan, or Index Full Scan then we can only parallelize the operation if the index is partitioned.
Pcwc is missing in inout section
Hi Amrit,
PCWC stands for PARALLEL COMBINED WITH CHILD.
In this case, the Parent operation is Line 7 of the plan or the distribution of blocks from the LINEORDERS table among the parallel server process, i.e., the children of this operation. On line 8 of the plan, we see the parallel server processes scan those blocks and apply the where clause predicate to those scanned rows. This is the Child operation. So, lines 7 and 8 are tied together, and PCWC and PCWP in the IN-OUT column indicate which line is the Parent and which is the Child.