ORA-00600: [kghstack_free1]
                                                 Last update (2011-04-20 15:18:19)
                                                                                                                   Date added (2009-04-03 21:22:37)

Summary
Using Oracle10g with HP-UX Itanium when trying a parallel update you might get the error

ORA-12801: error signaled in parallel query server P077
ORA-00600: internal error code, arguments: [kghstack_free1], [kdu_clone_kduu:kduu[kd]col], [], []

For example the following statement will generate ORA-00600

update /*+ PARALLEL(TT,16)  */ CUSTOMER_VIEW.CUSTOMER_VIEW_FCT TT
set TOTAL_ACCOUNTS_REG=TOTAL_ACT_ACCOUNTS-(TOTAL_ACCOUNTS_DUN+TOTAL_ACCOUNTS_TEAM);

Workaround
1. Either do the update without the parallel hint
or
2. recreate the table with CTAS. First create a new table X with CTAS, rename the old table to Y and rename the X to old table name, after that you can do the parallel update.