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After applying the rollback from the Critical Patch Updates PATCH 33583921 – GI Jan 2022 Release Update 12.2.0.1.220118 at both Oracle RAC Databases 12.2.0.1 and GRID 12.2.0.1, I found the following messages on the alert log of the database:
2022-04-05T15:45:29.630130+02:00 Exception [type: SIGSEGV, Address not mapped to object] [ADDR:0x0] [PC:0x2425E8B, qkaProjRwo()+139] [flags: 0x0, count: 1] Errors in file techdatabasket1_ora_21181.trc (incident=2085): ORA-07445: exception encountered: core dump [qkaProjRwo()+139] [SIGSEGV] [ADDR:0x0] [PC:0x2425E8B] [Address not mapped to object] [] Incident details in: techdatabasket_ora_21181_i2085.trc Use ADRCI or Support Workbench to package the incident. See Note 411.1 at My Oracle Support for error and packaging details.
After some investigation, I found that the error “ORA-7445 [kcbm_sim_one()+1288] [SIGSEGV]” is very generic and often the argument [kcbm_sim_one()] is related to many known bugs on the Oracle database from versions 10.1 to 10.4. However, in version 12.1, there is also a new type of argument for this bug.
Additionally, I noticed that the error above appeared on the alert log every time a specific SQL query with global variables ran on the database. Although that the failure message for the SQL was different on the prompt as below:
ERROR at line 44: ORA-03113: end-of-file on communication channel Process ID: 12576 Session ID: 1172 Serial number: 45510
While a patch is not applied to fix this bug or upgrade this database, there are two workarounds to be able to execute the type of SQL above that involve adding one of the two hidden parameters below on the database level:
SQL> alter system set "_complex_view_merging"=false scope=both sid='*'; System altered. or SQL> alter system set "_OPTIMIZER_COST_BASED_TRANSFORMATION"= OFF scope=both sid='*'; System altered.
I hope this post helps you! If you want to read more about some related errors, check the following sources below:
Ora7445 [kcbm_sim_one()+1288] [SIGSEGV] [ADDR:0xC109CCD18] [PC:0x104D4FF68] [Address not mapped to object] [] (Doc ID 2223940.1)
ORA-07445: Exception Encountered: Core Dump [kkqctJuxtaposeGBP()+674] [SIGSEGV] [ADDR:0x0] [PC:0xAFB (Doc ID 2121160.1)
12.2:ORA-07445: exception encountered: core dump [kkpapDFindPFkk()+401] [SIGSEGV] [ADDR:0x20030] [PC:0x35C1E41] [Address not mapped to object] [] (Doc ID 2716913.1)
Hi! I am Bruno, a Brazilian born and bred. Former Oracle ACE, Computer Scientist, MSc in Data Science, over ten years of experience in companies such as IBM, Epico Tech, and Playtech based in three different countries (Brazil, Hungary, and Sweden) and joined projects remotely in many others. I am super excited to show you my interest in Databases, Cloud, Data Science, Data Engineering, Bigdata, AI, Programming, Software Engineering, and data in general.
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