From a63dde5a5b9a519ad2e4343c1d0b27de5bf41fc0 Mon Sep 17 00:00:00 2001
From: unknown <kostja@dipika.(none)>
Date: Tue, 8 Apr 2008 20:01:20 +0400
Subject: Tentative implementation of WL#4165 Prepared statements: validation
 WL#4166 Prepared statements: automatic re-prepare Fixes Bug#27430 Crash in
 subquery code when in PS and table DDL changed after PREPARE Bug#27690
 Re-execution of prepared statement after table was replaced with a view
 crashes Bug#27420 A combination of PS and view operations cause error +
 assertion on shutdown

The basic idea of the patch is to keep track of table metadata between
prepared statement prepare and execute. If some table used in the statement
has changed, the prepared statement is re-prepared before execution.

See WL#4165 and WL#4166 contents and comments in the code for details
of the implementation.


include/my_global.h:
  Remove 'register' keyword to avoid warnings when swapping large structures
  that don't fit into a register. Any modern compiler is capable of placing
  a variable in a register when that would benefit performance.
mysql-test/r/ps_1general.result:
  Update test results: since now we re-prepare automatically,
  more correct results are produced in prepare-ddl-execute scenario.
mysql-test/r/query_cache_merge.result:
  Ensure that the table definition cache is large enough for
  the test to pass in --ps-protocol
mysql-test/r/trigger.result:
  Update test results to reflect automatic statement reprepare.
mysql-test/t/disabled.def:
  Enable ps_ddl.test, which now passes.
mysql-test/t/ps_1general.test:
  Since now we re-execute prepared statements after DDL successfully,
  change the test to produce repeatable results. Remove expectancy of
  an error in one place where now we automatically reprepare the prepared
  statement.
mysql-test/t/query_cache_merge.test:
  Ensure the table definition cache is large enough for the test to pass
  in --ps-protocol
mysql-test/t/trigger.test:
  Sinc
sql/item.cc:
  Implement Item_param "copy" functionality, used at re-prepare of
  a prepared statement.
  We copy the type of the original parameter, and move the assigned value,
  if any. Sic, the value is "moved", since it can be quite big --
  e.g. in case we deal with a LONG DATA parameter.
  It's essential to move the value from the old parameter since
  at the time of re-prepare the client packet with the necessary information
  may be not available.
sql/item.h:
  Declare a new method used for reprepare.
sql/my_decimal.h:
  Implement "swap()" functionality of class my_decimal to be
  able to easily swap two decimal values.
sql/mysql_priv.h:
  Declare enum_metadata_type.
sql/mysqld.cc:
  Implement a status variable for the number of reprepared statements.
sql/sql_base.cc:
  Implement metadata version validation.
sql/share/errmsg.txt:
  Add two new error messages: ER_NEED_REPREPARE and ER_PS_REBIND.
  The first error (theoretically) never reaches the user.
  It is issued by the metadata validation framework when a metadata version
  has changed between prepare and execute. Later on it's intercepted
  and the statement is automatically re-prepared. Only if the error
  has occurred repeatedly MAX_REPREPARE_ATTEMTS (3) times do we
  return it to the user.

  The second error is issued when after re-prepare we discover
  that the metadata we sent over to the client using the binary
  protocol differs drammatically from the new result set metadata
  that the reprepared statement produces (e.g. number of result
  set columns is different).
sql/sql_class.cc:
  Implement metadata version validation framework.
sql/sql_class.h:
  Declarations for metadata version validation framework.
sql/sql_parse.cc:
  Mark commands for which we must invalidate and reprepare a prepared
  statement when metadata has changed.
sql/sql_prepare.cc:
  Implement WL#4165 and WL#4166 (limited support of metadata validation
  and re-prepare).
sql/table.h:
  Implement metadata validation.
tests/mysql_client_test.c:
  Add a test case for WL#4166
---
 mysql-test/r/trigger.result | 1 -
 1 file changed, 1 deletion(-)

(limited to 'mysql-test/r/trigger.result')

diff --git a/mysql-test/r/trigger.result b/mysql-test/r/trigger.result
index e7f5c41513b..35d5134fa6b 100644
--- a/mysql-test/r/trigger.result
+++ b/mysql-test/r/trigger.result
@@ -820,7 +820,6 @@ call p1();
 drop trigger t1_bi;
 create trigger t1_bi after insert on t1 for each row insert into t3 values (new.id);
 execute stmt1;
-ERROR 42S02: Table 'test.t3' doesn't exist
 call p1();
 ERROR 42S02: Table 'test.t3' doesn't exist
 deallocate prepare stmt1;
-- 
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