database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-12-24 11:21:21 +03:00
Code Activity

Fix for BUG#20188 "REPLACE or ON DUPLICATE KEY UPDATE in

Browse Source 
auto_increment breaks binlog":
if slave's table had a higher auto_increment counter than master's (even
though all rows of the two tables were identical), then in some cases,
REPLACE and INSERT ON DUPLICATE KEY UPDATE failed to replicate
statement-based (it inserted different values on slave from on master).
write_record() contained a "thd->next_insert_id=0" to force an adjustment
of thd->next_insert_id after the update or replacement. But it is this
assigment introduced indeterminism of the statement on the slave, thus
the bug. For ON DUPLICATE, we replace that assignment by a call to
handler::adjust_next_insert_id_after_explicit_value() which is deterministic
(does not depend on slave table's autoinc counter). For REPLACE, this
assignment can simply be removed (as REPLACE can't insert a number larger
than thd->next_insert_id).
We also move a too early restore_auto_increment() down to when we really know
that we can restore the value.


mysql-test/r/rpl_insert_id.result:
  result update, without the bugfix, slave's "3 350" were "4 350".
mysql-test/t/rpl_insert_id.test:
  test for BUG#20188 "REPLACE or ON DUPLICATE KEY UPDATE in
  auto_increment breaks binlog".
  There is, in this order:
  - a test of the bug for the case of REPLACE
  - a test of basic ON DUPLICATE KEY UPDATE functionality which was not
  tested before
  - a test of the bug for the case of ON DUPLICATE KEY UPDATE
sql/handler.cc:
  the adjustment of next_insert_id if inserting a big explicit value, is
  moved to a separate method to be used elsewhere.
sql/handler.h:
  see handler.cc
sql/sql_insert.cc:
  restore_auto_increment() means "I know I won't use this autogenerated
  autoincrement value, you are free to reuse it for next row". But we were
  calling restore_auto_increment() in the case of REPLACE: if write_row() fails
  inserting the row, we don't know that we won't use the value, as we are going to
  try again by doing internally an UPDATE of the existing row, or a DELETE
  of the existing row and then an INSERT. So I move restore_auto_increment()
  further down, when we know for sure we failed all possibilities for the row.
  Additionally, in case of REPLACE, we don't need to reset THD::next_insert_id:
  the value of thd->next_insert_id will be suitable for the next row.
  In case of ON DUPLICATE KEY UPDATE, resetting thd->next_insert_id is also
  wrong (breaks statement-based binlog), but cannot simply be removed, as
  thd->next_insert_id must be adjusted if the explicit value exceeds it.
  We now do the adjustment by calling
  handler::adjust_next_insert_id_after_explicit_value() (which, contrary to
  thd->next_insert_id=0, does not depend on the slave table's autoinc counter,
  and so is deterministic).
This commit is contained in:
unknown
2006-07-05 14:41:35 +02:00
parent 57e7bc5513
commit 4e9d7d6c4b
5 changed files with 157 additions and 24 deletions
Download Patch File Download Diff File Expand all files Collapse all files

32
sql/handler.cc
View File

@@ -1471,6 +1471,26 @@ next_insert_id(ulonglong nr,struct system_variables *variables)
}
void handler::adjust_next_insert_id_after_explicit_value(ulonglong nr)
{
/*
If we have set THD::next_insert_id previously and plan to insert an
explicitely-specified value larger than this, we need to increase
THD::next_insert_id to be greater than the explicit value.
*/
THD *thd= table->in_use;
if (thd->clear_next_insert_id && (nr >= thd->next_insert_id))
{
if (thd->variables.auto_increment_increment != 1)
nr= next_insert_id(nr, &thd->variables);
else
nr++;
thd->next_insert_id= nr;
DBUG_PRINT("info",("next_insert_id: %lu", (ulong) nr));
}
}
/*
Update the auto_increment field if necessary
@@ -1547,17 +1567,7 @@ bool handler::update_auto_increment()
/* Clear flag for next row */
/* Mark that we didn't generate a new value **/
auto_increment_column_changed=0;
/* Update next_insert_id if we have already generated a value */
if (thd->clear_next_insert_id && nr >= thd->next_insert_id)
{
if (variables->auto_increment_increment != 1)
nr= next_insert_id(nr, variables);
else
nr++;
thd->next_insert_id= nr;
DBUG_PRINT("info",("next_insert_id: %lu", (ulong) nr));
}
adjust_next_insert_id_after_explicit_value(nr);
DBUG_RETURN(0);
}
if (!(nr= thd->next_insert_id))