I forgot…
No FK constraints (or any constraints aside from NOT NULL constraints on the
table).
Nothing odd about the table. It is a plain old heap organized table.
Thanks,
Jeremy
From: Sheehan, Jeremy
Sent: Friday, April 27, 2018 1:27 PM
To: 'Chris Taylor' <christopherdtaylor1994@xxxxxxxxx>
Cc: ORACLE-L <oracle-l@xxxxxxxxxxxxx>
Subject: RE: Tuning Advice
Excellent! I will give this a try and see how it works!
Thanks for the help Chris!
Jeremy
From: Chris Taylor [mailto:christopherdtaylor1994@xxxxxxxxx]
Sent: Friday, April 27, 2018 12:22 PM
To: Sheehan, Jeremy <JEREMY.SHEEHAN@xxxxxxx<mailto:JEREMY.SHEEHAN@xxxxxxx>>
Cc: ORACLE-L <oracle-l@xxxxxxxxxxxxx<mailto:oracle-l@xxxxxxxxxxxxx>>
Subject: Re: Tuning Advice
CAUTION - EXTERNAL EMAIL
Questions:
1. Does the inserted table have constraints - especially FK contraints back to
a parent table?
2. Is there anything unusual about the table being inserted such as being an
IOT , partitioned etc?
Tips:
1. Execute your SELECT sql (without the INSERT) and then immediately execute :
select * from table(dbms_xplan.display_cursor(null,null,'ADVANCED IOSTATS
LAST'))
/
From that output you can grab everything under the OUTLINE section - it's a big
hint and you can add that to your SELECT statement and use it in your insert.
For example let's say your output under OUTLINE DATA looks something like:
/*+
BEGIN_OUTLINE_DATA
IGNORE_OPTIM_EMBEDDED_HINTS
OPTIMIZER_FEATURES_ENABLE('12.1.0.2')
DB_VERSION('12.1.0.2')
OPT_PARAM('_optim_peek_user_binds' 'false')
OPT_PARAM('optimizer_dynamic_sampling' 0)
OPT_PARAM('_bloom_filter_enabled' 'false')
OPT_PARAM('_optimizer_use_feedback' 'false')
OPT_PARAM('_px_adaptive_dist_method' 'off')
OPT_PARAM('_optimizer_dsdir_usage_control' 0)
OPT_PARAM('_optimizer_adaptive_plans' 'false')
OPT_PARAM('_optimizer_strans_adaptive_pruning' 'false')
OPT_PARAM('_optimizer_gather_feedback' 'false')
OPT_PARAM('_optimizer_aggr_groupby_elim' 'false')
OPT_PARAM('_optimizer_reduce_groupby_key' 'false')
OPT_PARAM('_optimizer_nlj_hj_adaptive_join' 'false')
OPT_PARAM('_fix_control' '20355502:8')
ALL_ROWS
OUTLINE_LEAF(@"SEL$1")
FULL(@"SEL$1" "N"@"SEL$1")
END_OUTLINE_DATA
*/
Then your INSERT would become:
INSERT into my_table (col1, col2, col3, colN)
SELECT /*+
BEGIN_OUTLINE_DATA
IGNORE_OPTIM_EMBEDDED_HINTS
OPTIMIZER_FEATURES_ENABLE('12.1.0.2')
DB_VERSION('12.1.0.2')
OPT_PARAM('_optim_peek_user_binds' 'false')
OPT_PARAM('optimizer_dynamic_sampling' 0)
OPT_PARAM('_bloom_filter_enabled' 'false')
OPT_PARAM('_optimizer_use_feedback' 'false')
OPT_PARAM('_px_adaptive_dist_method' 'off')
OPT_PARAM('_optimizer_dsdir_usage_control' 0)
OPT_PARAM('_optimizer_adaptive_plans' 'false')
OPT_PARAM('_optimizer_strans_adaptive_pruning' 'false')
OPT_PARAM('_optimizer_gather_feedback' 'false')
OPT_PARAM('_optimizer_aggr_groupby_elim' 'false')
OPT_PARAM('_optimizer_reduce_groupby_key' 'false')
OPT_PARAM('_optimizer_nlj_hj_adaptive_join' 'false')
OPT_PARAM('_fix_control' '20355502:8')
ALL_ROWS
OUTLINE_LEAF(@"SEL$1")
FULL(@"SEL$1" "N"@"SEL$1")
END_OUTLINE_DATA
*/
col1, col2, col3, colN from my_other_table;
HTH
Chris
On Fri, Apr 27, 2018 at 10:50 AM, Sheehan, Jeremy
<JEREMY.SHEEHAN@xxxxxxx<mailto:JEREMY.SHEEHAN@xxxxxxx>> wrote:
Hello Gurus,
Oracle 12.1.0.2
AIX 7.1
I have a query that runs fairly well. Takes about 8 minutes to run, nothing
terrible about it (no huge FTS, joins seem to be in place correctly). When I
try to do an insert into TABLE as SELECT, it picks a completely different
execution plan and never finishes. The really odd thing is that it works great
when using CTAS or initial creation of a MV.
Any suggestion on how I can have the optimizer not use a specific execution
plan or any session level parameters that would have it use a different
execution plan?
Thanks in advance!
Jeremy
