After upgrading an Oracle database from version 18.7 to 19.12, queries began encountering errors such as ORA-07445 and ORA-00600, causing instance crashes. The errors seemed related to parsing and transformation components in the SQL processing pipeline. Adding more physical memory resolved the issue, indicating the new database version required more memory than the previous configuration.

1. After upgrade oracle database from 18.7 to 19.12 we faced issues for our quires. For example below
errors occurred for some of quires:
ORA-07445: exception encountered: core dump [qcsabe_worker()+6] [SIGSEGV]
[ADDR:0x7FFF0CF89FF8] [PC:0x12DD87D6] [Address not mapped to object] []
ORA-07445: exception encountered: core dump [kkqojeanl()+836] [SIGSEGV]
[ADDR:0x7FFEFB4E5FB8] [PC:0x12C09734] [Address not mapped to object] []
Another error that caused instance crash was:
ORA-00600 [99999]
Queries that used of large inlists encountered the ora-07445 error. In general in oracle maximum
number of expressions in a list is 1000. If a program needs more than this should use of OR switch to
join inlists. By this method we can have inlist queries with 20000 or more item in our inlist.
Arguments in the ORA-07445
qcsabe: semantic analysis
kkqojeanl: expression analyze
It seems the errors relates to Parsing and Transformation components . Below tree shows that our
problem occurred in SQL Transformation component:
SQL_Compiler
→ SQL_Parser (qcs)
→SQL_Semantic
→SQL_Optimizer
→SQL_Transform (kkq)
Solutions:
1. Based on oracle docid 1577011.1 we should replace our large inlists with temporary table. But
this solution for us is not possible because these are SAP standard transactions.
2. Disable oracle transformation features by change below parameters:
_optimizer_cost_based_transformation
_optimizer_free_transformation_heap
_optimizer_use_cbqt_star_transformation

2. _optimizer_vector_transformation
But this doesn’t resolve our problem.
3. Probing the ora-00600 error and it shows us there is a problem in Oracle Resource Management
layer. It means Resource Management caused to crash the database. Of course we didn’t used
this feature at all. By checking trace files related to DB crash we guessed our problem relates to
lake of Physical Memory (RAM) and by adding Memory our problem has been solved. It means
the configuration that worked in 18.7 in 19.12 needs more memory.
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