Hi!
>>>>> "Nihal" == Nihal Dindar <dindarn@stripped> writes:
Nihal> Hi,
Nihal> Thank you very much for your reply, but I still couldn't figure out how
Nihal> to solve the problem.
Michael-> To be able to help you we would need more information at which place in the
code you need access to the data for an old/new record.
Nihal> I do work on finding specified(at query) patterns between rows for my
Nihal> thesis. Because of this reason, at execution phase I need to move
Nihal> between some rows and run the expression on both old and current rows
Nihal> [sql/sql_select.cc, inside evaluate_join_record method].
Nihal> Where does it specified the record that val_xxx run on? In
table-> record[], join_tab->readrecord.record or somewhere else?
Normally in table->record[],
The exception is in case of 'summary records', like those generated by
the seoond phase of "select field,count(*) from table group by field".
For the second phase there is no easy way for you to get access to
other rows, but that shouldn't be relevant for you.
Michael-> The record data is normally in table->record_buffer[]. The length of this
buffer is table->reclength.
Nihal> I am using the code of mysql-6.0.3-alpha and table doesn't have
Nihal> reclength field. Should I use table->s->reclength instead?
Yes. table->s is a shared structure that holds all constants that are
equal for two table objects from the same table.
Regards,
Monty
