Merge lp:~posulliv/mysql-server/query-rewrite into lp:~mysql/mysql-server/mysql-next-mr

[Padraig O'Sullivan]

This branch contains a new plugin type for query rewriting.

Based on discussions on the internals mailing list, I added 2 distinct plugin points where a plugin developer could choose to rewrite a query:

 1) pre-parsing
 2) post-parsing

In the pre-parsing case, the raw query string is passed to the plugin. If the plugin rewrites the raw query, it returns a new string which is then set as the current query by the MySQL kernel. There is also a callback function for freeing memory allocated for the rewritten query text in the plugin.

In the post-parsing case, the parse tree structure is passed as a parameter to the plugin. A plugin developer can modify the parse tree in place if they wish. MySQL will operate on the parse tree after this function returns.

I also included a simple example query rewriting plugin which simply converts the raw text of a query to lower case.

I logged bug 57459 as a feature request for this since this was suggested on the mailing list.

[lp:~posulliv/mysql-server/query-rewrite]

3205. By Padraig O'Sullivan on 2010-10-15

Forgot new method when embedded server is defined.

Unmerged revisions

3205. By Padraig O'Sullivan on 2010-10-15

Forgot new method when embedded server is defined.

3204. By Padraig O'Sullivan on 2010-10-15

Added another plugin point for query rewrite which allows the parse tree to be rewritten.

3203. By Padraig O'Sullivan on 2010-10-13

Removed one call to query rewrite plugin point which is unneeded.

3202. By Padraig O'Sullivan on 2010-10-13

Updated query rewrite plugin interface and how query rewrite plugins are called from within the kernel.

3201. By Padraig O'Sullivan on 2010-10-13

Modified locations where query rewrite plugin point is to be always before mysql_parse function. This makes sure the rewritten query is placed in the general query log and also ensures the rewritten query is the query that shows up in profiling output.

3200. By Padraig O'Sullivan on 2010-10-13

Added functions for initializing and finalizing query rewrite plugins.

3199. By Padraig O'Sullivan on 2010-10-13

Update sample rewriting plugin to work with autoconf tools. Added preprocessor generated file for query rewrite interface.

3198. By Padraig O'Sullivan on 2010-10-11

Merge trunk.

3197. By Padraig O'Sullivan on 2010-09-11

Added simple query rewriting plugin that simply converts a query to lower case.

3196. By Padraig O'Sullivan on 2010-09-11

Added files to call into query rewrite plugins.

=== modified file 'Makefile.am'
--- Makefile.am	2010-08-27 07:20:08 +0000
+++ Makefile.am	2010-10-15 16:16:49 +0000
@@ -267,6 +267,7 @@
 
 API_PREPROCESSOR_HEADER = $(top_srcdir)/include/mysql/plugin_audit.h \
 			$(top_srcdir)/include/mysql/plugin_ftparser.h \
+			$(top_srcdir)/include/mysql/plugin_query_rewrite.h \
 			$(top_srcdir)/include/mysql.h \
 			$(top_srcdir)/include/mysql/psi/psi_abi_v1.h \
 			$(top_srcdir)/include/mysql/psi/psi_abi_v2.h

=== modified file 'include/mysql/plugin.h'
--- include/mysql/plugin.h	2010-09-01 13:06:14 +0000
+++ include/mysql/plugin.h	2010-10-15 16:16:49 +0000
@@ -42,10 +42,13 @@
 
 #ifdef __cplusplus
 class THD;
+class LEX;
 class Item;
 #define MYSQL_THD THD*
+#define MYSQL_LEXPTR LEX*
 #else
 #define MYSQL_THD void*
+#define MYSQL_LEXPTR void*
 #endif
 
 #include <mysql/services.h>
@@ -82,8 +85,9 @@
 #define MYSQL_DAEMON_PLUGIN          3  /* The daemon/raw plugin type */
 #define MYSQL_INFORMATION_SCHEMA_PLUGIN  4  /* The I_S plugin type */
 #define MYSQL_AUDIT_PLUGIN           5  /* The Audit plugin type        */
-#define MYSQL_REPLICATION_PLUGIN     6	/* The replication plugin type */
-#define MYSQL_MAX_PLUGIN_TYPE_NUM    7  /* The number of plugin types   */
+#define MYSQL_QUERY_REWRITE_PLUGIN   6	/* The query rewrite plugin type */
+#define MYSQL_REPLICATION_PLUGIN     7	/* The replication plugin type */
+#define MYSQL_MAX_PLUGIN_TYPE_NUM    8  /* The number of plugin types   */
 
 /* We use the following strings to define licenses for plugins */
 #define PLUGIN_LICENSE_PROPRIETARY 0
@@ -422,6 +426,11 @@
 #include "plugin_ftparser.h"
 
 /*************************************************************************
+  API for query rewrite plugin. (MYSQL_QUERY_REWRITE_PLUGIN)
+*/
+#include "plugin_query_rewrite.h"
+
+/*************************************************************************
   API for Storage Engine plugin. (MYSQL_DAEMON_PLUGIN)
 */
 

=== modified file 'include/mysql/plugin_audit.h.pp'
--- include/mysql/plugin_audit.h.pp	2010-08-30 14:07:40 +0000
+++ include/mysql/plugin_audit.h.pp	2010-10-15 16:16:49 +0000
@@ -143,6 +143,16 @@
   int (*init)(MYSQL_FTPARSER_PARAM *param);
   int (*deinit)(MYSQL_FTPARSER_PARAM *param);
 };
+#include "plugin_query_rewrite.h"
+#include <stdint.h>
+#include "plugin.h"
+struct st_mysql_query_rewrite
+{
+  int interface_version;
+  char* (*rewrite_query)(const char* schema, size_t schema_len, const char* query, size_t orig_query_len, size_t* rewritten_query_len);
+  void (*free_rewritten_query)(char* query);
+  void (*rewrite_parse_tree)(void* thd, void* parse_tree);
+};
 struct st_mysql_daemon
 {
   int interface_version;

=== modified file 'include/mysql/plugin_ftparser.h.pp'
--- include/mysql/plugin_ftparser.h.pp	2010-08-30 14:07:40 +0000
+++ include/mysql/plugin_ftparser.h.pp	2010-10-15 16:16:49 +0000
@@ -96,6 +96,16 @@
   void * __reserved1;
 };
 #include "plugin_ftparser.h"
+#include "plugin_query_rewrite.h"
+#include <stdint.h>
+#include "plugin.h"
+struct st_mysql_query_rewrite
+{
+  int interface_version;
+  char* (*rewrite_query)(const char* schema, size_t schema_len, const char* query, size_t orig_query_len, size_t* rewritten_query_len);
+  void (*free_rewritten_query)(char* query);
+  void (*rewrite_parse_tree)(void* thd, void* parse_tree);
+};
 struct st_mysql_daemon
 {
   int interface_version;

=== added file 'include/mysql/plugin_query_rewrite.h'
--- include/mysql/plugin_query_rewrite.h	1970-01-01 00:00:00 +0000
+++ include/mysql/plugin_query_rewrite.h	2010-10-15 16:16:49 +0000
@@ -0,0 +1,54 @@
+/* Copyright (C) 2010 Akiban Technologies
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+#ifndef _my_query_rewrite_h
+#define _my_query_rewrite_h
+
+#include <stdint.h>
+
+/*************************************************************************
+  API for query rewrite plugin. (MYSQL_QUERY_REWRITE_PLUGIN)
+*/
+
+#include "plugin.h"
+
+#define MYSQL_QUERY_REWRITE_INTERFACE_VERSION 0x0200
+
+/*************************************************************************
+  Here we define the descriptor structure, that is referred from
+  st_mysql_plugin.
+
+  rewrite_query() is invoked before a query is parsed allowing a plugin
+  the opporunity to rewrite the query string passed as a parameter
+  to the function
+
+  free_rewritten_query() is invoked only if a plugin rewrote the text of a query.
+  It frees any memory a plugin allocated for the rewritten query.
+
+  rewrite_parse_tree() is invoked after a query is parsed by MySQL. It
+  gives a rewriting plugin the opportunity to modify the parse tree
+  generated by MySQL. This allows a plugin developer to rewrite a query
+  without having to worry about parsing a query.
+*/
+struct st_mysql_query_rewrite
+{
+  int interface_version;
+  char* (*rewrite_query)(const char* schema, size_t schema_len, const char* query, size_t orig_query_len, size_t* rewritten_query_len);
+  void (*free_rewritten_query)(char* query);
+  void (*rewrite_parse_tree)(MYSQL_THD thd, MYSQL_LEXPTR parse_tree);
+};
+
+
+#endif /* _my_query_rewrite_h */

=== added file 'include/mysql/plugin_query_rewrite.h.pp'
--- include/mysql/plugin_query_rewrite.h.pp	1970-01-01 00:00:00 +0000
+++ include/mysql/plugin_query_rewrite.h.pp	2010-10-15 16:16:49 +0000
@@ -0,0 +1,198 @@
+#include <stdint.h>
+#include "plugin.h"
+#include <mysql/services.h>
+#include <mysql/service_my_snprintf.h>
+extern struct my_snprintf_service_st {
+  size_t (*my_snprintf_type)(char*, size_t, const char*, ...);
+  size_t (*my_vsnprintf_type)(char *, size_t, const char*, va_list);
+} *my_snprintf_service;
+size_t my_snprintf(char* to, size_t n, const char* fmt, ...);
+size_t my_vsnprintf(char *to, size_t n, const char* fmt, va_list ap);
+#include <mysql/service_thd_alloc.h>
+struct st_mysql_lex_string
+{
+  char *str;
+  size_t length;
+};
+typedef struct st_mysql_lex_string MYSQL_LEX_STRING;
+extern struct thd_alloc_service_st {
+  void *(*thd_alloc_func)(void*, unsigned int);
+  void *(*thd_calloc_func)(void*, unsigned int);
+  char *(*thd_strdup_func)(void*, const char *);
+  char *(*thd_strmake_func)(void*, const char *, unsigned int);
+  void *(*thd_memdup_func)(void*, const void*, unsigned int);
+  MYSQL_LEX_STRING *(*thd_make_lex_string_func)(void*, MYSQL_LEX_STRING *,
+                                        const char *, unsigned int, int);
+} *thd_alloc_service;
+void *thd_alloc(void* thd, unsigned int size);
+void *thd_calloc(void* thd, unsigned int size);
+char *thd_strdup(void* thd, const char *str);
+char *thd_strmake(void* thd, const char *str, unsigned int size);
+void *thd_memdup(void* thd, const void* str, unsigned int size);
+MYSQL_LEX_STRING *thd_make_lex_string(void* thd, MYSQL_LEX_STRING *lex_str,
+                                      const char *str, unsigned int size,
+                                      int allocate_lex_string);
+#include <mysql/service_thd_wait.h>
+typedef enum _thd_wait_type_e {
+  THD_WAIT_MUTEX= 1,
+  THD_WAIT_DISKIO= 2,
+  THD_WAIT_ROW_TABLE_LOCK= 3,
+  THD_WAIT_GLOBAL_LOCK= 4
+} thd_wait_type;
+extern struct thd_wait_service_st {
+  void (*thd_wait_begin_func)(void*, thd_wait_type);
+  void (*thd_wait_end_func)(void*);
+} *thd_wait_service;
+void thd_wait_begin(void* thd, thd_wait_type wait_type);
+void thd_wait_end(void* thd);
+#include <mysql/service_thread_scheduler.h>
+struct scheduler_functions;
+extern struct my_thread_scheduler_service {
+  int (*set)(struct scheduler_functions *scheduler);
+  int (*reset)();
+} *my_thread_scheduler_service;
+int my_thread_scheduler_set(struct scheduler_functions *scheduler);
+int my_thread_scheduler_reset();
+struct st_mysql_xid {
+  long formatID;
+  long gtrid_length;
+  long bqual_length;
+  char data[128];
+};
+typedef struct st_mysql_xid MYSQL_XID;
+enum enum_mysql_show_type
+{
+  SHOW_UNDEF, SHOW_BOOL, SHOW_INT, SHOW_LONG,
+  SHOW_LONGLONG, SHOW_CHAR, SHOW_CHAR_PTR,
+  SHOW_ARRAY, SHOW_FUNC, SHOW_DOUBLE,
+  SHOW_always_last
+};
+struct st_mysql_show_var {
+  const char *name;
+  char *value;
+  enum enum_mysql_show_type type;
+};
+typedef int (*mysql_show_var_func)(void*, struct st_mysql_show_var*, char *);
+struct st_mysql_sys_var;
+struct st_mysql_value;
+typedef int (*mysql_var_check_func)(void* thd,
+                                    struct st_mysql_sys_var *var,
+                                    void *save, struct st_mysql_value *value);
+typedef void (*mysql_var_update_func)(void* thd,
+                                      struct st_mysql_sys_var *var,
+                                      void *var_ptr, const void *save);
+struct st_mysql_plugin
+{
+  int type;
+  void *info;
+  const char *name;
+  const char *author;
+  const char *descr;
+  int license;
+  int (*init)(void *);
+  int (*deinit)(void *);
+  unsigned int version;
+  struct st_mysql_show_var *status_vars;
+  struct st_mysql_sys_var **system_vars;
+  void * __reserved1;
+};
+#include "plugin_ftparser.h"
+#include "plugin.h"
+enum enum_ftparser_mode
+{
+  MYSQL_FTPARSER_SIMPLE_MODE= 0,
+  MYSQL_FTPARSER_WITH_STOPWORDS= 1,
+  MYSQL_FTPARSER_FULL_BOOLEAN_INFO= 2
+};
+enum enum_ft_token_type
+{
+  FT_TOKEN_EOF= 0,
+  FT_TOKEN_WORD= 1,
+  FT_TOKEN_LEFT_PAREN= 2,
+  FT_TOKEN_RIGHT_PAREN= 3,
+  FT_TOKEN_STOPWORD= 4
+};
+typedef struct st_mysql_ftparser_boolean_info
+{
+  enum enum_ft_token_type type;
+  int yesno;
+  int weight_adjust;
+  char wasign;
+  char trunc;
+  char prev;
+  char *quot;
+} MYSQL_FTPARSER_BOOLEAN_INFO;
+typedef struct st_mysql_ftparser_param
+{
+  int (*mysql_parse)(struct st_mysql_ftparser_param *,
+                     char *doc, int doc_len);
+  int (*mysql_add_word)(struct st_mysql_ftparser_param *,
+                        char *word, int word_len,
+                        MYSQL_FTPARSER_BOOLEAN_INFO *boolean_info);
+  void *ftparser_state;
+  void *mysql_ftparam;
+  struct charset_info_st *cs;
+  char *doc;
+  int length;
+  int flags;
+  enum enum_ftparser_mode mode;
+} MYSQL_FTPARSER_PARAM;
+struct st_mysql_ftparser
+{
+  int interface_version;
+  int (*parse)(MYSQL_FTPARSER_PARAM *param);
+  int (*init)(MYSQL_FTPARSER_PARAM *param);
+  int (*deinit)(MYSQL_FTPARSER_PARAM *param);
+};
+#include "plugin_query_rewrite.h"
+struct st_mysql_daemon
+{
+  int interface_version;
+};
+struct st_mysql_information_schema
+{
+  int interface_version;
+};
+struct st_mysql_storage_engine
+{
+  int interface_version;
+};
+struct handlerton;
+ struct Mysql_replication {
+   int interface_version;
+ };
+struct st_mysql_value
+{
+  int (*value_type)(struct st_mysql_value *);
+  const char *(*val_str)(struct st_mysql_value *, char *buffer, int *length);
+  int (*val_real)(struct st_mysql_value *, double *realbuf);
+  int (*val_int)(struct st_mysql_value *, long long *intbuf);
+  int (*is_unsigned)(struct st_mysql_value *);
+};
+int thd_in_lock_tables(const void* thd);
+int thd_tablespace_op(const void* thd);
+long long thd_test_options(const void* thd, long long test_options);
+int thd_sql_command(const void* thd);
+const char *thd_proc_info(void* thd, const char *info);
+void **thd_ha_data(const void* thd, const struct handlerton *hton);
+void thd_storage_lock_wait(void* thd, long long value);
+int thd_tx_isolation(const void* thd);
+char *thd_security_context(void* thd, char *buffer, unsigned int length,
+                           unsigned int max_query_len);
+void thd_inc_row_count(void* thd);
+int mysql_tmpfile(const char *prefix);
+int thd_killed(const void* thd);
+unsigned long thd_get_thread_id(const void* thd);
+void thd_get_xid(const void* thd, MYSQL_XID *xid);
+void mysql_query_cache_invalidate4(void* thd,
+                                   const char *key, unsigned int key_length,
+                                   int using_trx);
+void *thd_get_ha_data(const void* thd, const struct handlerton *hton);
+void thd_set_ha_data(void* thd, const struct handlerton *hton,
+                     const void *ha_data);
+struct st_mysql_query_rewrite
+{
+  int interface_version;
+  char* (*rewrite_query)(const char* schema, size_t schema_len, const char* query, size_t orig_query_len, size_t* rewritten_query_len);
+  void (*free_rewritten_query)(char* query);
+};

=== removed file 'include/probes_mysql_nodtrace.h'
--- include/probes_mysql_nodtrace.h	2010-03-01 00:06:27 +0000
+++ include/probes_mysql_nodtrace.h	1970-01-01 00:00:00 +0000
@@ -1,129 +0,0 @@
-/*
- * Generated by dheadgen(1).
- */
-
-#ifndef	_PROBES_MYSQL_D
-#define	_PROBES_MYSQL_D
-
-#ifdef	__cplusplus
-extern "C" {
-#endif
-
-#define	MYSQL_CONNECTION_START(arg0, arg1, arg2)
-#define	MYSQL_CONNECTION_START_ENABLED() (0)
-#define	MYSQL_CONNECTION_DONE(arg0, arg1)
-#define	MYSQL_CONNECTION_DONE_ENABLED() (0)
-#define	MYSQL_COMMAND_START(arg0, arg1, arg2, arg3)
-#define	MYSQL_COMMAND_START_ENABLED() (0)
-#define	MYSQL_COMMAND_DONE(arg0)
-#define	MYSQL_COMMAND_DONE_ENABLED() (0)
-#define	MYSQL_QUERY_START(arg0, arg1, arg2, arg3, arg4)
-#define	MYSQL_QUERY_START_ENABLED() (0)
-#define	MYSQL_QUERY_DONE(arg0)
-#define	MYSQL_QUERY_DONE_ENABLED() (0)
-#define	MYSQL_QUERY_PARSE_START(arg0)
-#define	MYSQL_QUERY_PARSE_START_ENABLED() (0)
-#define	MYSQL_QUERY_PARSE_DONE(arg0)
-#define	MYSQL_QUERY_PARSE_DONE_ENABLED() (0)
-#define	MYSQL_QUERY_CACHE_HIT(arg0, arg1)
-#define	MYSQL_QUERY_CACHE_HIT_ENABLED() (0)
-#define	MYSQL_QUERY_CACHE_MISS(arg0)
-#define	MYSQL_QUERY_CACHE_MISS_ENABLED() (0)
-#define	MYSQL_QUERY_EXEC_START(arg0, arg1, arg2, arg3, arg4, arg5)
-#define	MYSQL_QUERY_EXEC_START_ENABLED() (0)
-#define	MYSQL_QUERY_EXEC_DONE(arg0)
-#define	MYSQL_QUERY_EXEC_DONE_ENABLED() (0)
-#define	MYSQL_INSERT_ROW_START(arg0, arg1)
-#define	MYSQL_INSERT_ROW_START_ENABLED() (0)
-#define	MYSQL_INSERT_ROW_DONE(arg0)
-#define	MYSQL_INSERT_ROW_DONE_ENABLED() (0)
-#define	MYSQL_UPDATE_ROW_START(arg0, arg1)
-#define	MYSQL_UPDATE_ROW_START_ENABLED() (0)
-#define	MYSQL_UPDATE_ROW_DONE(arg0)
-#define	MYSQL_UPDATE_ROW_DONE_ENABLED() (0)
-#define	MYSQL_DELETE_ROW_START(arg0, arg1)
-#define	MYSQL_DELETE_ROW_START_ENABLED() (0)
-#define	MYSQL_DELETE_ROW_DONE(arg0)
-#define	MYSQL_DELETE_ROW_DONE_ENABLED() (0)
-#define	MYSQL_READ_ROW_START(arg0, arg1, arg2)
-#define	MYSQL_READ_ROW_START_ENABLED() (0)
-#define	MYSQL_READ_ROW_DONE(arg0)
-#define	MYSQL_READ_ROW_DONE_ENABLED() (0)
-#define	MYSQL_INDEX_READ_ROW_START(arg0, arg1)
-#define	MYSQL_INDEX_READ_ROW_START_ENABLED() (0)
-#define	MYSQL_INDEX_READ_ROW_DONE(arg0)
-#define	MYSQL_INDEX_READ_ROW_DONE_ENABLED() (0)
-#define	MYSQL_HANDLER_RDLOCK_START(arg0, arg1)
-#define	MYSQL_HANDLER_RDLOCK_START_ENABLED() (0)
-#define	MYSQL_HANDLER_WRLOCK_START(arg0, arg1)
-#define	MYSQL_HANDLER_WRLOCK_START_ENABLED() (0)
-#define	MYSQL_HANDLER_UNLOCK_START(arg0, arg1)
-#define	MYSQL_HANDLER_UNLOCK_START_ENABLED() (0)
-#define	MYSQL_HANDLER_RDLOCK_DONE(arg0)
-#define	MYSQL_HANDLER_RDLOCK_DONE_ENABLED() (0)
-#define	MYSQL_HANDLER_WRLOCK_DONE(arg0)
-#define	MYSQL_HANDLER_WRLOCK_DONE_ENABLED() (0)
-#define	MYSQL_HANDLER_UNLOCK_DONE(arg0)
-#define	MYSQL_HANDLER_UNLOCK_DONE_ENABLED() (0)
-#define	MYSQL_FILESORT_START(arg0, arg1)
-#define	MYSQL_FILESORT_START_ENABLED() (0)
-#define	MYSQL_FILESORT_DONE(arg0, arg1)
-#define	MYSQL_FILESORT_DONE_ENABLED() (0)
-#define	MYSQL_SELECT_START(arg0)
-#define	MYSQL_SELECT_START_ENABLED() (0)
-#define	MYSQL_SELECT_DONE(arg0, arg1)
-#define	MYSQL_SELECT_DONE_ENABLED() (0)
-#define	MYSQL_INSERT_START(arg0)
-#define	MYSQL_INSERT_START_ENABLED() (0)
-#define	MYSQL_INSERT_DONE(arg0, arg1)
-#define	MYSQL_INSERT_DONE_ENABLED() (0)
-#define	MYSQL_INSERT_SELECT_START(arg0)
-#define	MYSQL_INSERT_SELECT_START_ENABLED() (0)
-#define	MYSQL_INSERT_SELECT_DONE(arg0, arg1)
-#define	MYSQL_INSERT_SELECT_DONE_ENABLED() (0)
-#define	MYSQL_UPDATE_START(arg0)
-#define	MYSQL_UPDATE_START_ENABLED() (0)
-#define	MYSQL_UPDATE_DONE(arg0, arg1, arg2)
-#define	MYSQL_UPDATE_DONE_ENABLED() (0)
-#define	MYSQL_MULTI_UPDATE_START(arg0)
-#define	MYSQL_MULTI_UPDATE_START_ENABLED() (0)
-#define	MYSQL_MULTI_UPDATE_DONE(arg0, arg1, arg2)
-#define	MYSQL_MULTI_UPDATE_DONE_ENABLED() (0)
-#define	MYSQL_DELETE_START(arg0)
-#define	MYSQL_DELETE_START_ENABLED() (0)
-#define	MYSQL_DELETE_DONE(arg0, arg1)
-#define	MYSQL_DELETE_DONE_ENABLED() (0)
-#define	MYSQL_MULTI_DELETE_START(arg0)
-#define	MYSQL_MULTI_DELETE_START_ENABLED() (0)
-#define	MYSQL_MULTI_DELETE_DONE(arg0, arg1)
-#define	MYSQL_MULTI_DELETE_DONE_ENABLED() (0)
-#define	MYSQL_NET_READ_START()
-#define	MYSQL_NET_READ_START_ENABLED() (0)
-#define	MYSQL_NET_READ_DONE(arg0, arg1)
-#define	MYSQL_NET_READ_DONE_ENABLED() (0)
-#define	MYSQL_NET_WRITE_START(arg0)
-#define	MYSQL_NET_WRITE_START_ENABLED() (0)
-#define	MYSQL_NET_WRITE_DONE(arg0)
-#define	MYSQL_NET_WRITE_DONE_ENABLED() (0)
-#define	MYSQL_KEYCACHE_READ_START(arg0, arg1, arg2, arg3)
-#define	MYSQL_KEYCACHE_READ_START_ENABLED() (0)
-#define	MYSQL_KEYCACHE_READ_BLOCK(arg0)
-#define	MYSQL_KEYCACHE_READ_BLOCK_ENABLED() (0)
-#define	MYSQL_KEYCACHE_READ_HIT()
-#define	MYSQL_KEYCACHE_READ_HIT_ENABLED() (0)
-#define	MYSQL_KEYCACHE_READ_MISS()
-#define	MYSQL_KEYCACHE_READ_MISS_ENABLED() (0)
-#define	MYSQL_KEYCACHE_READ_DONE(arg0, arg1)
-#define	MYSQL_KEYCACHE_READ_DONE_ENABLED() (0)
-#define	MYSQL_KEYCACHE_WRITE_START(arg0, arg1, arg2, arg3)
-#define	MYSQL_KEYCACHE_WRITE_START_ENABLED() (0)
-#define	MYSQL_KEYCACHE_WRITE_BLOCK(arg0)
-#define	MYSQL_KEYCACHE_WRITE_BLOCK_ENABLED() (0)
-#define	MYSQL_KEYCACHE_WRITE_DONE(arg0, arg1)
-#define	MYSQL_KEYCACHE_WRITE_DONE_ENABLED() (0)
-
-#ifdef  __cplusplus
-}
-#endif
-
-#endif  /* _PROBES_MYSQL_D */

=== added directory 'plugin/rewrite_lower'
=== added file 'plugin/rewrite_lower/CMakeLists.txt'
--- plugin/rewrite_lower/CMakeLists.txt	1970-01-01 00:00:00 +0000
+++ plugin/rewrite_lower/CMakeLists.txt	2010-10-15 16:16:49 +0000
@@ -0,0 +1,17 @@
+# Copyright (c) 2006, 2010, Oracle and/or its affiliates. All rights reserved.
+# 
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; version 2 of the License.
+# 
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+
+MYSQL_ADD_PLUGIN(rewrite_lower rewrite_lower.cc
+  MODULE_ONLY MODULE_OUTPUT_NAME "rewrite_lower")

=== added file 'plugin/rewrite_lower/Makefile.am'
--- plugin/rewrite_lower/Makefile.am	1970-01-01 00:00:00 +0000
+++ plugin/rewrite_lower/Makefile.am	2010-10-15 16:16:49 +0000
@@ -0,0 +1,32 @@
+# Copyright (C) 2006 MySQL AB
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; version 2 of the License.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+## Makefile.am for query rewrite plugin that converts a query to lower case
+
+pkgplugindir =		$(pkglibdir)/plugin
+INCLUDES =              -I$(top_srcdir)/include \
+			-I$(top_srcdir)/sql \
+			-I$(top_srcdir)/regex \
+			-I$(srcdir)
+
+#noinst_HEADERS = rewrite_lower.h
+
+pkgplugin_LTLIBRARIES =	rewrite_lower.la
+rewrite_lower_la_LDFLAGS =	-module -rpath $(pkgplugindir) -L$(top_builddir)/libservices -lmysqlservices -lstdc++
+rewrite_lower_la_CXXFLAGS=	$(AM_CXXFLAGS) -DMYSQL_DYNAMIC_PLUGIN
+rewrite_lower_la_CFLAGS =	$(AM_CFLAGS) -DMYSQL_DYNAMIC_PLUGIN
+rewrite_lower_la_SOURCES = rewrite_lower.cc
+
+EXTRA_DIST=		plugin.in CMakeLists.txt

=== added file 'plugin/rewrite_lower/plug.in'
--- plugin/rewrite_lower/plug.in	1970-01-01 00:00:00 +0000
+++ plugin/rewrite_lower/plug.in	2010-10-15 16:16:49 +0000
@@ -0,0 +1,4 @@
+MYSQL_PLUGIN(rewrite_lower,[Convert query to lower-case Query Rewriting Plugin],
+        [Example query rewriting plugin.])
+MYSQL_PLUGIN_DYNAMIC(rewrite_lower,   [rewrite_lower.la])
+MYSQL_PLUGIN_STATIC(rewrite_lower,  [librewritelower.a])

=== added file 'plugin/rewrite_lower/rewrite_lower.cc'
--- plugin/rewrite_lower/rewrite_lower.cc	1970-01-01 00:00:00 +0000
+++ plugin/rewrite_lower/rewrite_lower.cc	2010-10-15 16:16:49 +0000
@@ -0,0 +1,84 @@
+/* Copyright (C) 2010 Akiban Technologies
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA */
+
+#include <ctype.h>
+#include <string.h>
+
+#include <mysql/plugin.h>
+#include <mysql/plugin_query_rewrite.h>
+
+using namespace std;
+
+static char* rewrite_lower(const char*,
+						   size_t,
+						   const char* query,
+						   size_t original_query_len,
+                           size_t* rewritten_query_len)
+{
+  char* rewritten_query= new char[original_query_len];
+  memcpy(rewritten_query, query, original_query_len);
+  while (*rewritten_query++ = tolower(*rewritten_query));
+  *rewritten_query_len= original_query_len;
+  return (rewritten_query - (original_query_len + 1));
+}
+
+
+static void free_rewritten_query(char* query)
+{
+  delete [] query;
+}
+
+
+static void null_parse_rewrite(MYSQL_THD, MYSQL_LEXPTR)
+{
+}
+
+
+static int rewrite_lower_plugin_init(void *)
+{
+  return 0;
+}
+
+static int rewrite_lower_plugin_deinit(void *)
+{
+  return 0;
+}
+
+static struct st_mysql_query_rewrite rewrite_lower_descriptor= {
+  MYSQL_QUERY_REWRITE_INTERFACE_VERSION, /* interface version */
+  rewrite_lower,                         /* rewrite function */
+  free_rewritten_query,                  /* free allocated memory for rewritten query */
+  null_parse_rewrite                     /* rewrite the parse tree (do nothing) */
+};
+
+/*
+  Plugin library descriptor
+*/
+mysql_declare_plugin(rewrite_lower)
+{
+  MYSQL_QUERY_REWRITE_PLUGIN,
+  &rewrite_lower_descriptor,
+  "rewrite_lower",
+  "Padraig O'Sullivan",
+  "Simple example query rewriting plugin",
+  PLUGIN_LICENSE_GPL,
+  rewrite_lower_plugin_init, /* Plugin Init */
+  rewrite_lower_plugin_deinit, /* Plugin Deinit */
+  0x0100 /* 1.0 */,
+  NULL,	/* status variables */
+  NULL,	/* system variables */
+  NULL  /* config options   */
+}
+mysql_declare_plugin_end;

=== modified file 'sql/CMakeLists.txt'
--- sql/CMakeLists.txt	2010-09-28 15:30:47 +0000
+++ sql/CMakeLists.txt	2010-10-15 16:16:49 +0000
@@ -67,7 +67,7 @@
                event_queue.cc event_db_repository.cc 
                sql_tablespace.cc events.cc ../sql-common/my_user.c 
                partition_info.cc sql_locale.cc
-               sql_servers.cc sql_audit.cc
+               sql_servers.cc sql_audit.cc sql_query_rewrite.cc
                sql_connect.cc scheduler.cc 
                sql_profile.cc event_parse_data.cc
                sql_bootstrap.cc

=== modified file 'sql/Makefile.am'
--- sql/Makefile.am	2010-08-20 09:15:16 +0000
+++ sql/Makefile.am	2010-10-15 16:16:49 +0000
@@ -130,7 +130,7 @@
 			sql_plugin.h authors.h event_parse_data.h \
 			event_data_objects.h event_scheduler.h \
 			sql_partition.h partition_info.h partition_element.h \
-			sql_audit.h sql_alter.h sql_partition_admin.h \
+			sql_audit.h sql_query_rewrite.h sql_alter.h sql_partition_admin.h \
 			contributors.h sql_servers.h sql_signal.h records.h \
 			sql_prepare.h rpl_handler.h replication.h mdl.h \
 			sql_cmd.h \
@@ -176,7 +176,7 @@
 			sql_plugin.cc \
 			sql_builtin.cc sql_tablespace.cc partition_info.cc \
 			sql_servers.cc event_parse_data.cc sql_signal.cc \
-			mdl.cc transaction.cc sql_audit.cc  \
+			mdl.cc transaction.cc sql_audit.cc  sql_query_rewrite.cc \
 			sha2.cc \
 			sql_alter.cc \
 			sql_partition_admin.cc

=== modified file 'sql/sql_parse.cc'
--- sql/sql_parse.cc	2010-09-01 22:59:33 +0000
+++ sql/sql_parse.cc	2010-10-15 16:16:49 +0000
@@ -99,6 +99,7 @@
 #include "probes_mysql.h"
 #include "set_var.h"
 #include "sql_bootstrap.h"
+#include "sql_query_rewrite.h"
 
 #define FLAGSTR(V,F) ((V)&(F)?#F" ":"")
 
@@ -556,6 +557,7 @@
       mode we have only one thread.
     */
     thd->set_time();
+    mysql_rewrite_raw_query(thd);
     Parser_state parser_state;
     if (parser_state.init(thd, thd->query(), length))
     {
@@ -1118,6 +1120,7 @@
     char *packet_end= thd->query() + thd->query_length();
     /* 'b' stands for 'buffer' parameter', special for 'my_snprintf' */
 
+    mysql_rewrite_raw_query(thd);
     general_log_write(thd, command, thd->query(), thd->query_length());
     DBUG_PRINT("query",("%-.4096s",thd->query()));
 #if defined(ENABLED_PROFILING)
@@ -5559,6 +5562,7 @@
       {
 	if (! thd->is_error())
 	{
+          mysql_rewrite_parse_tree(thd);
           const char *found_semicolon= parser_state->m_lip.found_semicolon;
           /*
             Binlog logs a string starting from thd->query and having length

=== modified file 'sql/sql_plugin.cc'
--- sql/sql_plugin.cc	2010-09-21 21:27:43 +0000
+++ sql/sql_plugin.cc	2010-10-15 16:16:49 +0000
@@ -64,6 +64,7 @@
   { C_STRING_WITH_LEN("DAEMON") },
   { C_STRING_WITH_LEN("INFORMATION SCHEMA") },
   { C_STRING_WITH_LEN("AUDIT") },
+  { C_STRING_WITH_LEN("QUERY REWRITE") },
   { C_STRING_WITH_LEN("REPLICATION") },
 };
 
@@ -73,6 +74,9 @@
 extern int initialize_audit_plugin(st_plugin_int *plugin);
 extern int finalize_audit_plugin(st_plugin_int *plugin);
 
+extern int initialize_query_rewrite_plugin(st_plugin_int *plugin);
+extern int finalize_query_rewrite_plugin(st_plugin_int *plugin);
+
 /*
   The number of elements in both plugin_type_initialize and
   plugin_type_deinitialize should equal to the number of plugins
@@ -81,13 +85,13 @@
 plugin_type_init plugin_type_initialize[MYSQL_MAX_PLUGIN_TYPE_NUM]=
 {
   0,ha_initialize_handlerton,0,0,initialize_schema_table,
-  initialize_audit_plugin
+  initialize_audit_plugin,initialize_query_rewrite_plugin
 };
 
 plugin_type_init plugin_type_deinitialize[MYSQL_MAX_PLUGIN_TYPE_NUM]=
 {
   0,ha_finalize_handlerton,0,0,finalize_schema_table,
-  finalize_audit_plugin
+  finalize_audit_plugin,finalize_query_rewrite_plugin
 };
 
 #ifdef HAVE_DLOPEN
@@ -110,6 +114,7 @@
   MYSQL_DAEMON_INTERFACE_VERSION,
   MYSQL_INFORMATION_SCHEMA_INTERFACE_VERSION,
   MYSQL_AUDIT_INTERFACE_VERSION,
+  MYSQL_QUERY_REWRITE_INTERFACE_VERSION,
   MYSQL_REPLICATION_INTERFACE_VERSION
 };
 static int cur_plugin_info_interface_version[MYSQL_MAX_PLUGIN_TYPE_NUM]=
@@ -120,6 +125,7 @@
   MYSQL_DAEMON_INTERFACE_VERSION,
   MYSQL_INFORMATION_SCHEMA_INTERFACE_VERSION,
   MYSQL_AUDIT_INTERFACE_VERSION,
+  MYSQL_QUERY_REWRITE_INTERFACE_VERSION,
   MYSQL_REPLICATION_INTERFACE_VERSION
 };
 

=== added file 'sql/sql_query_rewrite.cc'
--- sql/sql_query_rewrite.cc	1970-01-01 00:00:00 +0000
+++ sql/sql_query_rewrite.cc	2010-10-15 16:16:49 +0000
@@ -0,0 +1,167 @@
+/* Copyright (c) 2010, Akiban Technologies. All rights reserved.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA */
+
+#include "sql_priv.h"
+#include "sql_parse.h"
+#include "sql_query_rewrite.h"
+
+extern int initialize_query_rewrite_plugin(st_plugin_int *plugin);
+extern int finalize_query_rewrite_plugin(st_plugin_int *plugin);
+
+#ifndef EMBEDDED_LIBRARY
+
+/**
+  Rewrites a query by invoking the plugin's query_rewrite method.  
+
+  @param[in] thd
+  @param[in] plugin
+  @param[in] arg
+
+  @retval FALSE  always
+*/
+static my_bool query_text_rewrite(THD *thd, 
+                                  plugin_ref plugin, 
+                                  void *)
+{
+  st_mysql_query_rewrite *data= plugin_data(plugin, struct st_mysql_query_rewrite *);
+
+  /* rewrite the query */
+  if (data)
+  {
+    size_t rewritten_query_len= 0;
+    char *rewritten_query= data->rewrite_query(thd->db, thd->db_length, thd->query(), thd->query_length(), &rewritten_query_len);
+    if (rewritten_query != NULL && rewritten_query_len > 0)
+    {
+      alloc_query(thd, rewritten_query, rewritten_query_len);
+      data->free_rewritten_query(rewritten_query);
+    }
+  }
+
+  return 0;
+}
+
+
+/**
+  Rewrites a query by invoking the plugin's rewrite_parse_tree method.  
+
+  @param[in] thd
+  @param[in] plugin
+  @param[in] arg
+
+  @retval FALSE  always
+*/
+static my_bool parse_tree_rewrite(THD *thd, 
+                                  plugin_ref plugin, 
+                                  void *)
+{
+  st_mysql_query_rewrite *data= plugin_data(plugin, struct st_mysql_query_rewrite *);
+
+  /* rewrite the parse tree */
+  if (data)
+  {
+    data->rewrite_parse_tree(thd, thd->lex);
+  }
+
+  return 0;
+}
+
+
+void mysql_rewrite_raw_query(THD *thd)
+{
+  plugin_foreach(thd, 
+                 query_text_rewrite, 
+                 MYSQL_QUERY_REWRITE_PLUGIN, 
+                 NULL);
+}
+
+
+void mysql_rewrite_parse_tree(THD *thd)
+{
+  plugin_foreach(thd, 
+                 parse_tree_rewrite, 
+                 MYSQL_QUERY_REWRITE_PLUGIN, 
+                 NULL);
+}
+
+/**
+  Initialize a query rewrite plug-in
+  
+  @param[in] plugin
+
+  @retval FALSE  OK
+  @retval TRUE   There was an error.
+*/
+int initialize_query_rewrite_plugin(st_plugin_int *plugin)
+{
+  if (plugin->plugin->init && plugin->plugin->init(NULL))
+  {
+    sql_print_error("Plugin '%s' init function returned error.",
+                    plugin->name.str);
+    return 1;
+  }
+
+  /* Make the interface info more easily accessible */
+  plugin->data= plugin->plugin->info;
+  
+  return 0;
+}
+
+
+/**
+  Finalize a query rewrite plug-in
+  
+  @param[in] plugin
+
+  @retval FALSE  OK
+  @retval TRUE   There was an error.
+*/
+int finalize_query_rewrite_plugin(st_plugin_int *plugin)
+{
+  if (plugin->plugin->deinit && plugin->plugin->deinit(NULL))
+  {
+    DBUG_PRINT("warning", ("Plugin '%s' deinit function returned error.",
+                            plugin->name.str));
+    DBUG_EXECUTE("finalize_query_rewrite_plugin", return 1; );
+  }
+  
+  plugin->data= NULL;
+  return 0;
+}
+
+#else /* EMBEDDED_LIBRARY */
+
+
+void mysql_rewrite_raw_query(THD *thd)
+{
+}
+
+
+void mysql_rewrite_parse_tree(THD *thd)
+{
+}
+
+
+int initialize_query_rewrite_plugin(st_plugin_int *plugin)
+{
+  return 1;
+}
+
+
+int finalize_query_rewrite_plugin(st_plugin_int *plugin)
+{
+  return 1;
+}
+
+#endif /* EMBEDDED_LIBRARY */

=== added file 'sql/sql_query_rewrite.h'
--- sql/sql_query_rewrite.h	1970-01-01 00:00:00 +0000
+++ sql/sql_query_rewrite.h	2010-10-15 16:16:49 +0000
@@ -0,0 +1,36 @@
+#ifndef SQL_QUERY_REWRITE_INCLUDED
+#define SQL_QUERY_REWRITE_INCLUDED
+
+/* Copyright (c) 2010, Akiban Technologies. All rights reserved.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA */
+
+
+#include <mysql/plugin_query_rewrite.h>
+#include "sql_class.h"
+
+/** 
+  Call query rewrite plugins on raw query text 
+  @param[in] thd thread with the query to be rewritten
+ */
+void mysql_rewrite_raw_query(THD *thd);
+
+
+/** 
+  Call query rewrite plugins on the parse tree
+  @param[in] thd thread with the parse tree to be rewritten
+ */
+void mysql_rewrite_parse_tree(THD *thd);
+
+#endif /* SQL_QUERY_REWRITE_INCLUDED */