It wasn't the Oracle upgrade. It was rather PCT_DIRECT_ACCESS - it went from 0
to 100. (Somebody updated block references.)
Sorry for the noise.
Best regards,
Nenad
From: Noveljic Nenad
Sent: Dienstag, 1. September 2020 18:51
To: ORACLE-L (oracle-l@xxxxxxxxxxxxx) <oracle-l@xxxxxxxxxxxxx>
Subject: IOT index costing in 19c
The cost estimation of an IOT secondary index dropped in 19c:
19
Index Stats::
Index: IX Col#: 1 4
LVLS: 3 #LB: 291921 #DK: 807941 LB/K: 1.00 DB/K: 26.00 CLUF: 21625156.00
NRW: 40118629.00 SSZ: 0.00 LGR: 0.00 CBK: 0.00 GQL: 100.00 CHR: 0.00 KQDFLG:
909455669 BSZ: 1
KKEISFLG: 1
12.2
Index Stats::
Index: IX Col#: 1 4
LVLS: 3 #LB: 272824 #DK: 699585 LB/K: 1.00 DB/K: 29.00 CLUF: 20503378.00
NRW: 38686507.00 SSZ: 0.00 LGR: 0.00 CBK: 0.00 GQL: 0.00 CHR: 0.00 KQDFLG: 1
BSZ: 1
KKEISFLG: 1
19
****** Costing Index IX
OPTIMIZER PERCENT INDEX CACHING = 0
SPD: Return code in qosdDSDirSetup: NODIR, estType = INDEX_SCAN
Estimated selectivity: 2.9279e-06 , col: #1
SPD: Return code in qosdDSDirSetup: NODIR, estType = INDEX_FILTER
Estimated selectivity: 2.9279e-06 , col: #1
Access Path: index (RangeScan)
Index: IX
resc_io: 67.317355 resc_cpu: 531351
ix_sel: 2.9279e-06 ix_sel_with_filters: 2.9279e-06
Cost: 67.339481 Resp: 67.339481 Degree: 1
****** Costing Index IX_BER02_PARTNER
12.2
****** Costing Index IX
OPTIMIZER PERCENT INDEX CACHING = 0
SPD: Return code in qosdDSDirSetup: NODIR, estType = INDEX_SCAN
Estimated selectivity: 2.9439e-06 , col: #1
SPD: Return code in qosdDSDirSetup: NODIR, estType = INDEX_FILTER
Estimated selectivity: 2.9439e-06 , col: #1
Access Path: index (RangeScan)
Index: IX
resc_io: 332.496503 resc_cpu: 2412554
ix_sel: 2.9439e-06 ix_sel_with_filters: 2.9439e-06
Cost: 332.596968 Resp: 332.596968 Degree: 1
The cost slumped from 332 in 12c to 67 in 19c.
A significant difference in the statistics is KQDFLG.
Does anybody understand this?
Best regards,
Nenad
http://nenadnoveljic.com/blog/
____________________________________________________
Please consider the environment before printing this e-mail.
Bitte denken Sie an die Umwelt, bevor Sie dieses E-Mail drucken.
<html xmlns="http://www.w3.org/1999/xhtml";>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<style type="text/css">p { font-family: Arial;font-size:9pt }</style>
</head>
<body>
<p>
<br>Important Notice</br>
<br />
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.<br />
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.<br />
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.</br>
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.<br />
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 <a
href="https://www.vontobel.com";>www.vontobel.com</a>.<br />
</p>
</body>
</html>
