2449423 - Error "main Bufman: Incorrect page header read" report in MPX with multiple writers - SAP IQ

• Running a multiplex environment with mulitple writer nodes or where the coordinator also modifies tables.
• Partial rollbacks of global transactions could lead to object corruption in SAP IQ.
• In some cases the corruption is irrecoverable, meaning even select into from corrupt object into temp table will fail.
• The following message can be seen in iqmsg file:

main Bufman: Incorrect page header read; from slib/s_trycatch.cxx:2928
expected: btype=13,blk=33296,pbn=979974326,nlb=16,npb=5,uid=10481352,txn=25897138,sp=1,mn=234,upmn=234,flgs=0x80000018,iscmp=1                        
read: btype=-161,nlb=59101,npb=49075,ctr=127,cta=222,pbn=6480671059100559359,txn=18446736851143229420,sp=4294967195,ver=255,pb=255,pus=59379 iscmp=1
Expected Pad1: 200 (0xc8), Pad2: 33296 (0x8210)
Got Pad1: 255 (0xff), Pad2: 59379 (0xe7f3)
There was an s_buf::Read() error during s_bufman::Find().

• The stacktrace function calls for the corruption could differ depending on where it is getting caught.

• sp_iqcheck 'allocation database' will report block count mismatches.

SAP IQ 16.0 SP11 PL05

Sybase , CR806769, CR#806769, 806769 , bufman , page corruption , stacktrace, stktrc , signal 11, abort , KBA , BC-SYB-IQ , Sybase IQ , Bug Filed