增加参数inception_osc_alter_foreign_keys_method，为了解决pt工具改表时

在没有外键的情况下，还是查information schema，导致在库表很多的情况下非常慢的问题，加上这个参数，默认为none，就不会去查了，速度非常快，并且可以减少内存的暴涨
tan-chao · Mar 23, 2016 · ddbe89f · ddbe89f
1 parent d9066ff
commit ddbe89f
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Showing 5 changed files with 23 additions and 2 deletions.
diff --git a/dbug/dbug.c b/dbug/dbug.c
@@ -244,7 +244,7 @@ static BOOLEAN init_done= FALSE; /* Set to TRUE when initialization done */
 */
 static struct settings init_settings;
 static const char *db_process= 0;/* Pointer to process name; argv[0] */
-my_bool _dbug_on_= TRUE;	 /* FALSE if no debugging at all */
+my_bool _dbug_on_= FALSE;	 /* FALSE if no debugging at all */
 
 typedef struct _db_code_state_ {
   const char *process;          /* Pointer to process name; usually argv[0] */

diff --git a/sql/sql_class.h b/sql/sql_class.h
@@ -928,6 +928,7 @@ typedef struct system_variables
   bool inception_osc_drop_new_table;
   bool inception_osc_check_replication_filters;
   bool inception_osc_check_alter;
+  ulong inception_alter_foreign_keys_method;
   ulong inception_osc_chunk_size;
   ulong inception_osc_max_running;
   ulong inception_osc_max_connected;

diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
@@ -192,6 +192,7 @@ const char *xa_state_names[]={
 #define INC_CHAR_MAX_TO_VARCHAR     16
 
 extern const char *osc_recursion_method[];
+extern const char *osc_alter_foreign_keys_method[];
 
 int mysql_check_subselect_item( THD* thd, st_select_lex *select_lex, bool top);
 int mysql_check_item( THD* thd, Item* item, st_select_lex *select_lex);
@@ -10383,7 +10384,10 @@ int mysql_execute_alter_table_osc(
     if (!thd->variables.inception_osc_check_alter)
         oscargv[count++] = strdup("--no-check-alter");
 
-    oscargv[count++] = strdup("--alter-foreign-keys-method=auto");
+    sprintf(cmd_line, "--alter-foreign-keys-method=%s", 
+        osc_alter_foreign_keys_method[thd->variables.inception_alter_foreign_keys_method]);
+    oscargv[count++] = strdup(cmd_line);
+
     oscargv[count++] = strdup("--execute");
     oscargv[count++] = strdup("--statistics");
     oscargv[count++] = strdup("--max-lag");

diff --git a/sql/sys_vars.cc b/sql/sys_vars.cc
@@ -1000,6 +1000,16 @@ static Sys_var_mybool Sys_inception_osc_check_alter(
     SESSION_VAR(inception_osc_check_alter),
     CMD_LINE(OPT_ARG), DEFAULT(TRUE));
 
+const char *osc_alter_foreign_keys_method[]= 
+{"auto", "none", "rebuild_constraints", "drop_swap", NullS};
+
+static Sys_var_enum Sys_inception_alter_foreign_keys_method(
+    "inception_osc_alter_foreign_keys_method",
+    "--alter-foreign-keys-method",
+    SESSION_VAR(inception_alter_foreign_keys_method), CMD_LINE(REQUIRED_ARG),
+    osc_alter_foreign_keys_method, DEFAULT(alter_foreign_keys_method_none), 
+    NO_MUTEX_GUARD, NOT_IN_BINLOG);
+
 const char *osc_recursion_method[]= {"processlist", "hosts", "none", NullS};
 static Sys_var_enum Sys_inception_osc_recursion_method(
     "inception_osc_recursion_method",

diff --git a/sql/sys_vars.h b/sql/sys_vars.h
@@ -1836,4 +1836,10 @@ enum enum_osc_recursion_method{
   recursion_method_unspec=3  
 };
 
+enum enum_osc_alter_foreign_keys_method{
+  alter_foreign_keys_method_auto =0,
+  alter_foreign_keys_method_none =1,
+  alter_foreign_keys_method_rebuild_constraints=2, 
+  alter_foreign_keys_method_drop_swap =3,
+};