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Informix - Problem description

Problem IT10384 Status: Closed

WITH AN LBAC PROTECTED TABLE SPL WHERE CLAUSE USING VARIABLE PARAMETER WILL
TAKE SEQUENTIAL SCAN

product:
INFORMIX SERVER / 5725A3900 / C10 - IDS 12.10
Problem description:
In SPL, a query like this, on an LBAC protected table, will 
yield an index access as expected: 
 
 select col2 into ret from my_tab where col1=10000; 
 
  1) informix.lbac_tab: INDEX PATH 
 
        Filters: LBACEnforceRow(informix.lbac_tab.lbl ) 
 
    (1) Index Name: andreasl.idx_lbac_tab_col1 
        Index Keys: col1   (Serial, fragments: ALL) 
        Lower Index Filter: informix.lbac_tab.col1 = 10000 
 
 
whereas the same query using a variable parameter instead of 
literal would take a sequential scan path: 
 
 let l_id = 10000; 
 select col2 into ret from my_tab where col1=l_id; 
 
  1) informix.lbac_tab: SEQUENTIAL SCAN  (Serial, fragments: 
ALL) 
 
        Filters: (LBACEnforceRow(informix.lbac_tab.lbl ) AND 
informix.lbac_tab.col1 = '<VAR>' ) 
 
 
Even when forcing index access, this index would be read 
sequentially: 
 
 let l_id = 10000; 
 select {+INDEX(lbac_tab idx_lbac_tab_id)} col2 into ret from 
my_tab where col1=l_id; 
 
 
  1) informix.lbac_tab: INDEX PATH 
 
        Filters: (LBACEnforceRow(informix.lbac_tab.lbl ) AND 
informix.lbac_tab.col1 = '<VAR>' ) 
 
    (1) Index Name: andreasl.idx_lbac_tab_col1 
        Index Keys: col1   (Serial, fragments: ALL) 
 
 
Explicitely updating statistics, or re-creating the index, would 
even make the second SPL (parametrized statement) fail with: 
 
  768: Internal error in routine lbac_chk_idx_fltrs: unsafe 
filter in index scan.
Problem Summary:
**************************************************************** 
* USERS AFFECTED:                                              * 
* All users                                                    * 
**************************************************************** 
* PROBLEM DESCRIPTION:                                         * 
* See Error Description                                        * 
**************************************************************** 
* RECOMMENDATION:                                              * 
* Update to IBM Informix Server 12.10.xC6                      * 
****************************************************************
Local Fix:


Solution


Problem Fixed In IBM Informix Server 12.10.xC6


Workaround


not known / see Local fix


Timestamps


Date  - problem reported    :
Date  - problem closed      :
Date  - last modified       :

28.07.2015
30.12.2015
30.12.2015


Problem solved at the following versions (IBM BugInfos)


12.10.xC6



Problem solved according to the fixlist(s) of the following version(s)


12.10.xC6

FixList