Nenad,
I didn't have a bug number relating to the DCL/LAT thing, just an
observation I had from a sample piece of code that got the wrong results.
If it's outer joins to laterval views possibly it relates to the equivalent
of a restriction on "join predicate pushdown" - do the predicate sections
show exactly the same correlation columns for the two accesses into the
VW_LAT when compared across the two execution plans, or does the insert
plan lose a correlation column on vw_lat usage that shows the huge cost and
cardinality ?
Regards
Jonathan Lewis
On Wed, Jun 24, 2020 at 12:06 PM Noveljic Nenad <nenad.noveljic@xxxxxxxxxxxx>
wrote:
- The source of VW_LAT are outer joins. It is an ANSI query, but without
any explicit lateral references.
- Bypassed unnestings and/or lateral view decorrelations might explain
less join permutations. I’ll examine the optimizer trace.
- Select plan runs in 10s, insert/select is running for hours.
- In a couple of hours I’ll be able to compare the result sets.
- You mean this: Plan Regression with VW_DCL (Lateral View Decorrelation)
in Explain Plan New Transformation in 12c Optimizer (Doc ID 2361393.1) ?
The optimizer indeed comes up with the poor plan for the select with
"_optimizer_ansi_rearchitecture" = false;
I'd say, DCL is done for select, but apparently has some limitations with
CTAS/INS. Rewriting the query to the Oracle syntax might be a workaround.
Best regards,
Nenad
http://nenadnoveljic.com/blog/
*From:* oracle-l-bounce@xxxxxxxxxxxxx <oracle-l-bounce@xxxxxxxxxxxxx> *On
Behalf Of *Jonathan Lewis
*Sent:* Mittwoch, 24. Juni 2020 11:47
*To:* ORACLE-L (oracle-l@xxxxxxxxxxxxx) <oracle-l@xxxxxxxxxxxxx>
*Subject:* Re: different plan with insert/select
First thoughts:
What's the source of the references to VW_LAT.... ? In line scalar
subqueries, existence subqueries, outer joins, or have these lateral views
appeared from a genuine ANSI lateral() that the optimizer has had to
transform?
At first sight it looks like the select statement has been able to do
something like unnesting one of them to a join while the insert has not
been allowed to unnest. (So one of those "not quite finished" patterns that
crops up so frequently at the edges).
Three other things -
a) Although the plan costs and estimates are vastly different is the work
similar - is it just an arithmetic error ?
b) Do the two plans get the same results ?
c) There used to be a bug relating to Oracle decorrelating lateral views
when it shouldn't. Possibly this has been fixed for selects but been
blocked for insert as select.
Regards
Jonathan Lewis
On Wed, Jun 24, 2020 at 9:52 AM Noveljic Nenad <
nenad.noveljic@xxxxxxxxxxxx> wrote:
It’s 19.7
Here’s the plan with select only:
------------------------------------------------------------------------------------------------------------------------
| Id | Operation | Name |
Rows | Bytes |TempSpc| Cost (%CPU)| Time |
------------------------------------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | |
47802 | 30M| | 233K (2)| 00:00:10 |
| 1 | COUNT |
| | | | | |
| 2 | MERGE JOIN OUTER | |
47802 | 30M| | 233K (2)| 00:00:10 |
|* 3 | HASH JOIN RIGHT OUTER | |
47802 | 29M| | 42098 (5)| 00:00:02 |
| 4 | TABLE ACCESS FULL | ALL_DIL_BOERSENPLATZ |
2348 | 96268 | | 8 (0)| 00:00:01 |
|* 5 | HASH JOIN OUTER | |
47802 | 28M| 17M| 42088 (5)| 00:00:02 |
|* 6 | HASH JOIN RIGHT OUTER | |
29913 | 17M| 5752K| 16418 (6)| 00:00:01 |
| 7 | TABLE ACCESS FULL | ALL_DIL_GVF |
256K| 2750K| | 1424 (4)| 00:00:01 |
|* 8 | HASH JOIN | |
29913 | 16M| | 14252 (6)| 00:00:01 |
|* 9 | INDEX RANGE SCAN | PK_ICR_MIT_BOOKKIND |
220 | 4400 | | 3 (0)| 00:00:01 |
|* 10 | TABLE ACCESS FULL | ICR_WRK_BEWEGUNG_FKR |
110K| 60M| | 14246 (6)| 00:00:01 |
| 11 | VIEW | |
5154K| 63M| | 20934 (5)| 00:00:01 |
|* 12 | HASH JOIN RIGHT OUTER | |
5154K| 280M| 8656K| 20934 (5)| 00:00:01 |
|* 13 | TABLE ACCESS FULL | ALL_DIL_BEWEGUNG |
276K| 5406K| | 5963 (5)| 00:00:01 |
|* 14 | INDEX FAST FULL SCAN | ALL_DIL_STEX_ORDER_LINK_PK |
5419K| 191M| | 6341 (6)| 00:00:01 |
| 15 | BUFFER SORT |
| 1 | 13 | | 233K (2)| 00:00:10 |
| 16 | VIEW | VW_LAT_AEC4E3BF
| 1 | 13 | | 4 (0)| 00:00:01 |
| 17 | NESTED LOOPS |
| 1 | 28 | | 4 (0)| 00:00:01 |
| 18 | NESTED LOOPS |
| 1 | 28 | | 4 (0)| 00:00:01 |
| 19 | TABLE ACCESS BY INDEX ROWID| ALL_DIL_WAEHRUNG_KURS
| 1 | 14 | | 2 (0)| 00:00:01 |
|* 20 | INDEX RANGE SCAN | PK_ALL_DIL_WAEHRUNG_KURS
| 1 | | | 1 (0)| 00:00:01 |
|* 21 | INDEX RANGE SCAN | PK_ALL_DIL_WAEHRUNG_KURS
| 1 | | | 1 (0)| 00:00:01 |
|* 22 | TABLE ACCESS BY INDEX ROWID | ALL_DIL_WAEHRUNG_KURS
| 1 | 14 | | 2 (0)| 00:00:01 |
And with insert:
--------------------------------------------------------------------------------------------------------------------------
| Id | Operation | Name |
Rows | Bytes |TempSpc| Cost (%CPU)| Time |
--------------------------------------------------------------------------------------------------------------------------
| 0 | INSERT STATEMENT |
| 154G| 92T| | 390M (5)| 04:14:24 |
| 1 | LOAD TABLE CONVENTIONAL | ICR_DAT_BEWEGUNG_FKR
| | | | | |
| 2 | COUNT |
| | | | | |
| 3 | MERGE JOIN OUTER |
| 154G| 92T| | 390M (5)| 04:14:24 |
| 4 | MERGE JOIN OUTER | |
29913 | 18M| | 136K (1)| 00:00:06 |
|* 5 | HASH JOIN RIGHT OUTER | |
29913 | 18M| | 16427 (6)| 00:00:01 |
| 6 | TABLE ACCESS FULL | ALL_DIL_BOERSENPLATZ
| 2348 | 96268 | | 8 (0)| 00:00:01 |
|* 7 | HASH JOIN RIGHT OUTER | |
29913 | 17M| 5752K| 16418 (6)| 00:00:01 |
| 8 | TABLE ACCESS FULL | ALL_DIL_GVF
| 256K| 2750K| | 1424 (4)| 00:00:01 |
|* 9 | HASH JOIN | |
29913 | 16M| | 14252 (6)| 00:00:01 |
|* 10 | INDEX RANGE SCAN | PK_ICR_MIT_BOOKKIND
| 220 | 4400 | | 3 (0)| 00:00:01 |
|* 11 | TABLE ACCESS FULL | ICR_WRK_BEWEGUNG_FKR
| 110K| 60M| | 14246 (6)| 00:00:01 |
| 12 | BUFFER SORT |
| 1 | 13 | | 136K (1)| 00:00:06 |
| 13 | VIEW | VW_LAT_7AEC37A2
| 1 | 13 | | 4 (0)| 00:00:01 |
| 14 | NESTED LOOPS |
| 1 | 28 | | 4 (0)| 00:00:01 |
| 15 | NESTED LOOPS |
| 1 | 28 | | 4 (0)| 00:00:01 |
| 16 | TABLE ACCESS BY INDEX ROWID| ALL_DIL_WAEHRUNG_KURS
| 1 | 14 | | 2 (0)| 00:00:01 |
|* 17 | INDEX RANGE SCAN | PK_ALL_DIL_WAEHRUNG_KURS
| 1 | | | 1 (0)| 00:00:01 |
|* 18 | INDEX RANGE SCAN | PK_ALL_DIL_WAEHRUNG_KURS
| 1 | | | 1 (0)| 00:00:01 |
|* 19 | TABLE ACCESS BY INDEX ROWID | ALL_DIL_WAEHRUNG_KURS
| 1 | 14 | | 2 (0)| 00:00:01 |
| 20 | BUFFER SORT |
| 5154K| | | 390M (5)| 04:14:24 |
| 21 | VIEW | VW_LAT_7AEC37A2
| 5154K| | | 13058 (5)| 00:00:01 |
|* 22 | FILTER |
| | | | | |
|* 23 | HASH JOIN RIGHT OUTER |
| 5154K| 280M| 8656K| 13058 (5)| 00:00:01 |
|* 24 | TABLE ACCESS FULL | ALL_DIL_BEWEGUNG
| 276K| 5406K| | 5963 (5)| 00:00:01 |
|* 25 | INDEX RANGE SCAN | ALL_DIL_STEX_ORDER_LINK_PK
| 4410K| 155M| | 3 (0)| 00:00:01 |
--------------------------------------------------------------------------------------------------------------------------
Thanks,
Nenad
*From:* oracle-l-bounce@xxxxxxxxxxxxx <oracle-l-bounce@xxxxxxxxxxxxx> *On
Behalf Of *Jonathan Lewis
*Sent:* Mittwoch, 24. Juni 2020 10:47
*To:* ORACLE-L (oracle-l@xxxxxxxxxxxxx) <oracle-l@xxxxxxxxxxxxx>
*Subject:* Re: different plan with insert/select
There's always the distributed query problem.
I've probably got a couple of other cases logged somewhere - will check
later and follow up
Which version of Oracle ?
Regards
Jonathan Lewis
On Wed, Jun 24, 2020 at 8:53 AM Noveljic Nenad <
nenad.noveljic@xxxxxxxxxxxx> wrote:
I’m getting a different execution plan for select if it runs in
insert/select statement. It’s the same select - embedded in an insert
statement.
There are much less join order permutations with insert/select than with
select. The initial join order 1 is different.
I’m working on finding out what exactly triggers the different behavior.
The original statement is rather complex, but I'm working on a simple,
generic test case.
Is anybody aware of possible causes?
Best regards,
Nenad
https://nenadnoveljic.com/blog
____________________________________________________
Please consider the environment before printing this e-mail.
Bitte denken Sie an die Umwelt, bevor Sie dieses E-Mail drucken.
Important Notice
This message is intended only for the individual named. It may contain
confidential or privileged information. If you are not the named addressee
you should in particular not disseminate, distribute, modify or copy this
e-mail. Please notify the sender immediately by e-mail, if you have
received this message by mistake and delete it from your system.
Without prejudice to any contractual agreements between you and us which
shall prevail in any case, we take it as your authorization to correspond
with you by e-mail if you send us messages by e-mail. However, we reserve
the right not to execute orders and instructions transmitted by e-mail at
any time and without further explanation.
E-mail transmission may not be secure or error-free as information could
be intercepted, corrupted, lost, destroyed, arrive late or incomplete. Also
processing of incoming e-mails cannot be guaranteed. All liability of
Vontobel Holding Ltd. and any of its affiliates (hereinafter collectively
referred to as "Vontobel Group") for any damages resulting from e-mail use
is excluded. You are advised that urgent and time sensitive messages should
not be sent by e-mail and if verification is required please request a
printed version. Please note that all e-mail communications to and from the
Vontobel Group are subject to electronic storage and review by Vontobel
Group. Unless stated to the contrary and without prejudice to any
contractual agreements between you and Vontobel Group which shall prevail
in any case, e-mail-communication is for informational purposes only and is
not intended as an offer or solicitation for the purchase or sale of any
financial instrument or as an official confirmation of any transaction.
The legal basis for the processing of your personal data is the legitimate
interest to develop a commercial relationship with you, as well as your
consent to forward you commercial communications. You can exercise, at any
time and under the terms established under current regulation, your rights.
If you prefer not to receive any further communications, please contact
your client relationship manager if you are a client of Vontobel Group or
notify the sender. Please note for an exact reference to the affected group
entity the corporate e-mail signature. For further information about data
privacy at Vontobel Group please consult www.vontobel.com.
Important Notice
This message is intended only for the individual named. It may contain
confidential or privileged information. If you are not the named addressee
you should in particular not disseminate, distribute, modify or copy this
e-mail. Please notify the sender immediately by e-mail, if you have
received this message by mistake and delete it from your system.
Without prejudice to any contractual agreements between you and us which
shall prevail in any case, we take it as your authorization to correspond
with you by e-mail if you send us messages by e-mail. However, we reserve
the right not to execute orders and instructions transmitted by e-mail at
any time and without further explanation.
E-mail transmission may not be secure or error-free as information could
be intercepted, corrupted, lost, destroyed, arrive late or incomplete. Also
processing of incoming e-mails cannot be guaranteed. All liability of
Vontobel Holding Ltd. and any of its affiliates (hereinafter collectively
referred to as "Vontobel Group") for any damages resulting from e-mail use
is excluded. You are advised that urgent and time sensitive messages should
not be sent by e-mail and if verification is required please request a
printed version. Please note that all e-mail communications to and from the
Vontobel Group are subject to electronic storage and review by Vontobel
Group. Unless stated to the contrary and without prejudice to any
contractual agreements between you and Vontobel Group which shall prevail
in any case, e-mail-communication is for informational purposes only and is
not intended as an offer or solicitation for the purchase or sale of any
financial instrument or as an official confirmation of any transaction.
The legal basis for the processing of your personal data is the legitimate
interest to develop a commercial relationship with you, as well as your
consent to forward you commercial communications. You can exercise, at any
time and under the terms established under current regulation, your rights.
If you prefer not to receive any further communications, please contact
your client relationship manager if you are a client of Vontobel Group or
notify the sender. Please note for an exact reference to the affected group
entity the corporate e-mail signature. For further information about data
privacy at Vontobel Group please consult www.vontobel.com.
Important Notice
This message is intended only for the individual named. It may contain
confidential or privileged information. If you are not the named addressee
you should in particular not disseminate, distribute, modify or copy this
e-mail. Please notify the sender immediately by e-mail, if you have
received this message by mistake and delete it from your system.
Without prejudice to any contractual agreements between you and us which
shall prevail in any case, we take it as your authorization to correspond
with you by e-mail if you send us messages by e-mail. However, we reserve
the right not to execute orders and instructions transmitted by e-mail at
any time and without further explanation.
E-mail transmission may not be secure or error-free as information could
be intercepted, corrupted, lost, destroyed, arrive late or incomplete. Also
processing of incoming e-mails cannot be guaranteed. All liability of
Vontobel Holding Ltd. and any of its affiliates (hereinafter collectively
referred to as "Vontobel Group") for any damages resulting from e-mail use
is excluded. You are advised that urgent and time sensitive messages should
not be sent by e-mail and if verification is required please request a
printed version. Please note that all e-mail communications to and from the
Vontobel Group are subject to electronic storage and review by Vontobel
Group. Unless stated to the contrary and without prejudice to any
contractual agreements between you and Vontobel Group which shall prevail
in any case, e-mail-communication is for informational purposes only and is
not intended as an offer or solicitation for the purchase or sale of any
financial instrument or as an official confirmation of any transaction.
The legal basis for the processing of your personal data is the legitimate
interest to develop a commercial relationship with you, as well as your
consent to forward you commercial communications. You can exercise, at any
time and under the terms established under current regulation, your rights.
If you prefer not to receive any further communications, please contact
your client relationship manager if you are a client of Vontobel Group or
notify the sender. Please note for an exact reference to the affected group
entity the corporate e-mail signature. For further information about data
privacy at Vontobel Group please consult www.vontobel.com.
