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MF65174 - LIC-DB-OTHER-PERFM PESSIMISTIC INDEX SCAN COSTING IS INFLATI

PTF ( Program Temporary Fixes ) Cover letter


Order this fix

Abstract

LIC-DB-OTHER-PERFM PESSIMISTIC INDEX SCAN COSTING IS INFLATI


Pre/Co-Requisite PTF / Fix List

REQ  LICENSED           PTF/FIX  LEVEL

TYPE PROGRAM  RELEASE   NUMBER   MIN/MAX  OPTION
---- -------- --------- -------  -------  ------
PRE  5770999  V7R3M0    MF63891   00/00    0000
PRE  5770999  V7R3M0    MF62341   00/00    0000
CO   5770999  V7R3M0    MF65146   00/00    0000
CO   5770999  V7R3M0    MF65144   00/00    0000
CO   5770999  V7R3M0    MF65143   00/00    0000
CO   5770999  V7R3M0    MF64006   00/00    0000
CO   5770999  V7R3M0    MF63946   00/00    0000
CO   5770999  V7R3M0    MF62344   00/00    0000
CO   5770999  V7R3M0    MF62345   00/00    0000



NOTICE:
-------
Application of this PTF may disable or render ineffective programs that
use system memory addresses not generated by the IBM translator,
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REGARDING THE PTF.





APAR Error Description / Circumvention

-----------------------------------------------
Under some circumstances, including the use of a commit control
level of *CS (Cursor Stability), queries that specify ordering
may run slowly. The optimizer may over-estimate the cost of an
access plan that uses an index scan to provide ordering and may
choose a less efficient ordering method.

CORRECTION FOR APAR MA47191 :
-----------------------------
The optimizer was using pessimistic costing in situations in
which it was not appropriate.  The optimizer logic has been
improved to avoid using pessimistic costing for these
situations.

CIRCUMVENTION FOR APAR MA47191 :
--------------------------------
None.


Activation Instructions


None.




Special Instructions


None.


Default Instructions

THIS PTF CAN BE APPLIED IMMEDIATE OR DELAYED.



Supersedes

PTF/FIX NO(S).  APAR TITLE LINE
--------------  ------------------------------------------------------------
   MF65145      LIC-DB-OTHER Allow duplicate keys in JSON_OBJECT and JSON_OB
   MF65070      OSP-DB-OTHER-INCORROUT UDTF - 'NO EXTERNAL ACTION'
   MF65057      LIC-DB-OTHER-PERFM SQL JOIN PERFORMANCE
   MF65040      OSP-PAR-940XMISC NEED TO ACCOUNT FOR DELETED ROWS IN COSTING
   MF65027      LIC-DB-OTHER-INCORROUT JSON_ARRAYAGG AND JSON_OBJECTAGG TRUN
   MF64896      OSP-DB-OTHER-F/DBOPAFFINITY-T/QQQOOODBOP-MSGMCH3203 A MSGMCH
   MF64813      LIC-DB-OTHER-F/HMDERIVEDHEAP-T/QQQOOODBOP-RCX/5094-MSGMCH320
   MF64808      OSP-PERFM PERFORMANCE PROBLEM CAUSED BY BAD ACCESS PLAN.
   MF64638      LIC-DB-OTHER-INCORROUT XMLAGG gives incorrect null values fo
   MF64510      OSP-DB SELECT FOR UPDATE WITH RS UNSELECTED RECORDS ARE LOCK
   MF64281      OSP-DB-OTHER-SAP400-THREADS-INCORROUT SELECT STMT WITH '=' ,
   MF64174      LIC-DB Internal Maintenance
   MF64157      LIC-DB-OTHER Internal Database Maintenance.
   MF64068      LIC-DB-OTHER Internal Database Maintenance.
   MF64007      LIC-DB-OTHER Internal Database Maintenance.
   MF63747      OSP-DB-OTHER-F/DBPMTRAP-MSGMCH3203 QRYDFN FAILS W/ MCH3203 F
   MF62911      LIC-DB-OTHER-F/DBPMTRAP-T/QQQOOODBOP-RC1720-MSGMCH3203 Outer
   MF63972      LIC-DB-OTHER-PERFM Improved I/O estimates for some queries
   MF63943      LIC-DB-PERFM reorder predicates based on selectivity
   MF63943      LIC-DB-PERFM reduce data copies for SQL query
   MF63897      LIC-DB Internal Maintenance
   MF63736      OSP-DB-OTHER-MSGCPI0999 XMLAGG QUERIES MAY RESULT IN LARGE A
   MF63736      OSP-DB-OTHER-MSGCPI0999 XMLAGG QUERIES MAY RESULT IN LARGE A
   MF63584      LIC-DB-OTHER-PERFM LEFT OUTER JOIN QUERY PERFORMANCE
   MF63580      LIC-DB-OTHER-PERFM COMPLEX QUERY IS BEING RE-OPTIMIZED UNEXP
   MF63446      LIC-DB-OTHER-UNPRED Grouping sets query fails when using an
   MF63408      LIC-DB-OTHER-PERFM DBPMSERVER TASKS DRIVING HIGH DISK LOAD F
   MF63408      LIC-DB-OTHER-PERFM DBPMSERVER TASKS DRIVING HIGH DISK LOAD F
   MF63300      LIC-DB Internal Maintenance
   MF62861      LIC-DB-PERFM VOLATILE TABLE IO Costing
   MF62857      LIC-DB-OTHER-PERFM Queries with an RRN Scan over an Encoded
   MF62635      LIC-DB Internal Maintenance
   MF62625      LIC-DB-OTHER Internal Database Maintenance.
   MF62544      LIC-DB-OTHER-INCORROUT Invalid values are not reported when
   MF62503      DB-LIC-MSGMCH3203 Plan Cache Snapshot  sEstimatedIoTimeInUs_
   MF62303      LIC-DB-PERFM SMP support for OLAP queries
   MF61691      LIC-DB-OTHER Query fails to optimize with SMP
   MF61542      LIC-DB-OTHER Increase database random Input/Output initial b
   MF62434      LIC-DB-OTHER Internal Database Maintenance.
   MF62371      LIC-DB-PERFM Not using EVI Only Access
   MF62342      LIC-DB-OTHER Optimizer support for PERCENTILE_DISC and PERCE
   MF62119      LIC-DB-OTHER Optimizer support for PERCENTILE_CONT and PERCE
   MF62043      LIC-DB-OTHER Internal database maintenance
   MF61902      LIC-DB-OTHER Internal database maintenance
   MF57964      LIC-DB-INCORROUT WHEN BOTH REGR_COUNT AND COUNT
   MF61726      LIC-DB PERFM LONG RUNNING SQL QUERY WITH EVI ACCESS.
   MF61156      LIC-DB-PERFM - EAO with Partitioned Tables
   MF60928      LIC-DB-PERFM SQL Honor KEEPINMEM MEMORY_POOL_PREFERENCE for
   MF60928      LIC-DB Visual Explain not showing Bitmap Icons
   MF60928      LIC-DB-PERFM SQL EVI Only Access query optimization techniqu
   MF61333      LIC-DB Internal Maintenance
   MF62035      LIC-DB-INCORROUT Regression functions with Grouping Sets
   MF62864      LIC-DB-PERFM Index Merge Ordering
   MF62577      LIC-DB-INCORROUT OLAP with ORDER BY of LOB
   MF61882      LIC-DB-PERFM Index Read Ahead when no RIO node
   MF61624      LIC-DB-OTHER-PERFM SQL query runs slowly due to index scan
   MF61589      LIC-DB-PERFM bad plan when running commit *ALL
   MF61589      LIC-DB-INCORROUT RowNumber and SUM OLAPs in same query
   MF61150      LIC-PERFM-PAR-940XMISC Bad Query Plan
   MF64878      LIC-DB-OTHER-INCORROUT UDTF - 'NO EXTERNAL ACTION' with LOB

Summary Information

System.............................. i
Models..............................
Release............................. V7R3M0
Licensed Program............... 5770999
APAR Fixed.......................... View details for APAR MA47191
Superseded by:...................... View fix details for PTF MF66658
Recompile........................... N
Library............................. QSYS
MRI Feature ........................ NONE
Cum Level........................... C9116730


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Document information

More support for: i family

Software version: V7R3M0

Operating system(s): OS/400

Reference #: MF65174

Modified date: 30 August 2018