LI73566: SQL STATMENTS CONTAINIG LIKE PREDICATES CAN LEAK MEMORY WHEN RUN AGAINST VIEWS, LEADS TO SQL0954

DB2 Version 9.1 Fix Pack 7  for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 6   for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 6a for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 7a  for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 8  for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 9  for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 10  for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 11  for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 12  for Linux, UNIX and Windows

APAR status

• Closed as program error.

Error description

• The following SQL statement:
  select * from testview where col1 like ?
  where the view is defined as:
  create view testview as select * from (values 'test') as TEST
      (col1) where 1 = 2
  will leak memory in the application heap. This can lead to
  SQL0954 errors.
  
  Running the same statement againast a normal table or a view
  defined as:
  create view testview as select * from (values 'test') as TEST
      (col1)
  will not leak memory.
  
  An additional indication is, that the rewritten SQL statement
  does not include the LIKE predicate anymore:
  SELECT NULL AS "COL1" FROM (VALUES) AS Q1 WHERE (1 = 2)
  

Local fix

• Remove the "WHERE 1 = 2" clausel from the view definition.
  

Problem summary

• The following SQL statement:
  select * from testview where col1 like ?
  where the view is defined as:
  create view testview as select * from (values 'test') as TEST
      (col1) where 1 = 2
  will leak memory in the application heap. This can lead to
  SQL0954 errors.
  
  Running the same statement againast a normal table or a view
  defined as:
  create view testview as select * from (values 'test') as TEST
      (col1)
  will not leak memory.
  
  An additional indication is, that the rewritten SQL statement
  does not include the LIKE predicate anymore:
  SELECT NULL AS "COL1" FROM (VALUES) AS Q1 WHERE (1 = 2)
  

Problem conclusion

• First fixed in DB2 UDB Version 9.1, FixPak 6.
  

Temporary fix

• See LOCAL FIX.
  

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  LI73629

Fix information

• Fixed component name

  DB2 UDE ESE LIN

• Fixed component ID

  5765F4104

Applicable component levels

• R810 PSN

     UP

• R820 PSN

     UP

• R910 PSN

     UP

• R950 PSN

     UP