Table definition cache, part 2

The table opening process now works the following way:
- Create common TABLE_SHARE object
- Read the .frm file and unpack it into the TABLE_SHARE object
- Create a TABLE object based on the information in the TABLE_SHARE
  object and open a handler to the table object

Other noteworthy changes:
- In TABLE_SHARE the most common strings are now LEX_STRING's
- Better error message when table is not found
- Variable table_cache is now renamed 'table_open_cache'
- New variable 'table_definition_cache' that is the number of table defintions that will be cached
- strxnmov() calls are now fixed to avoid overflows
- strxnmov() will now always add one end \0 to result
- engine objects are now created with a TABLE_SHARE object instead of a TABLE object.
- After creating a field object one must call field->init(table) before using it

- For a busy system this change will give you:
 - Less memory usage for table object
 - Faster opening of tables (if it's has been in use or is in table definition cache)
 - Allow you to cache many table definitions objects
 - Faster drop of table

1 files changed, 2 insertions, 2 deletions

diff --git a/sql/unireg.h b/sql/unireg.h
index d613392f831..9c11bd90f14 100644
--- a/sql/unireg.h
+++ b/sql/unireg.h
@@ -154,13 +154,13 @@
 #define DONT_GIVE_ERROR		256	/* Don't do frm_error on openfrm  */
 #define READ_SCREENS		1024	/* Read screens, info and helpfile */
 #define DELAYED_OPEN		4096	/* Open table later */
-#define NO_ERR_ON_NEW_FRM	8192	/* stop error sending on new format */
+#define OPEN_VIEW		8192	/* Allow open on view */
 
 #define SC_INFO_LENGTH 4		/* Form format constant */
 #define TE_INFO_LENGTH 3
 #define MTYP_NOEMPTY_BIT 128
 
-#define FRM_VER_TRUE_VARCHAR (FRM_VER+4)
+#define FRM_VER_TRUE_VARCHAR (FRM_VER+4) /* 10 */
 /*
   Minimum length pattern before Turbo Boyer-Moore is used
   for SELECT "text" LIKE "%pattern%", excluding the two