3502652 - Automatic database expansion triggers during a shrink - SAP ASE for Business Suite

• Automatic database expansion running while an alter database off a log device on the same database results in multiple errors.
  • From the alter database off:
    Error: 823, Severity: 24, State: 1
    I/O error detected during read for BUF=0x0x00000002db881770, MASS=0x0x00000002db881770, Buf#=0, page=0x0x000000027f888000, dbid=4, Mass vdevno=7, vpage=7333888, Buf lpage=5831936, Mass stat=0x4000100, Buf stat=0x1, size=16384, cid=0 ('default data cache'), Pinned xdes=0x(nil), spid=0.
    sddone: read error on virtual disk 7 block 5242880:
    sddone: 16384 bytes passed, 0 returned on read for virt disk 7 block 5242880
    Error: 12345, Severity: 20, State: 1
    Internal Error: Process 68 attempted to get an exclusive database disk map lock while holding an incompatible disk map lock. This request has been ignored to avoid this process blocking itself.
  • From the automatic database expansion:
    kernel  Performing space allocation for device '/sybase/xxx/saplog_1/xxx_log_001.dat' (4.00 Gb).  This may take some time.
    kernel  Finished initialization.
    
    
  • Afterword, the alter database off received a SEGV:
    Address 0x0x000000000118eba4 (altdb__findstranded+0x176)
    SQL causing error : alter database xxx log off xxx_log_001 = '10000M'
    along with the following stacktrace:
    altdb__findstranded
    altdb__shrinklog_backout
    altdb_shrinklog
    alterdb
    

• After alter database is done, the sysusages row no longer has the 10000MB hole row, and only has the 4GB alter from the database expansion and additionally is represented as a log hole.

  1> select * from master..sysusages where dbid=4 order by lstart
  2> go
   dbid   segmap      lstart     size       vstart      location unreservedpgs crdate                          vdevno
   ------ ----------- ---------- ---------- ----------- -------- ------------- ------------------------------- -----------

        4           0    5570560     262144     5570560        9        261120             Jul 22 2024  3:07PM          -4 

• Subsequent 692 error can be reported after attempting to write to this log hole:

  Error: 692, Severity: 20, State: 1
  Uninitialized logical page '5570560' was read while accessing database 'xxx' (4), object '' (99), index '<Unknown>' (0), partition '<Unknown>' (99). Please contact SAP Technical Support.

Adaptive Server Enterprise 16.0

database expansion, alter db, shrink , KBA , BC-DB-SYB , Business Suite on Adaptive Server Enterprise , Known Error