diff options
Diffstat (limited to 'include/myisam.h')
| -rw-r--r-- | include/myisam.h | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/include/myisam.h b/include/myisam.h index e502daa2f17..09f54ef0019 100644 --- a/include/myisam.h +++ b/include/myisam.h @@ -30,8 +30,30 @@ extern "C" { #ifndef _keycache_h #include "keycache.h" #endif -#include "my_handler.h" #include <mysql/plugin.h> +#include "my_compare.h" + +/* + There is a hard limit for the maximum number of keys as there are only + 8 bits in the index file header for the number of keys in a table. + This means that 0..255 keys can exist for a table. The idea of + HA_MAX_POSSIBLE_KEY is to ensure that one can use myisamchk & tools on + a MyISAM table for which one has more keys than MyISAM is normally + compiled for. If you don't have this, you will get a core dump when + running myisamchk compiled for 128 keys on a table with 255 keys. +*/ + +#define HA_MAX_POSSIBLE_KEY 255 /* For myisamchk */ +/* + The following defines can be increased if necessary. + But beware the dependency of MI_MAX_POSSIBLE_KEY_BUFF and HA_MAX_KEY_LENGTH. +*/ + +#define HA_MAX_KEY_LENGTH 1000 /* Max length in bytes */ +#define HA_MAX_KEY_SEG 16 /* Max segments for key */ + +#define HA_MAX_POSSIBLE_KEY_BUFF (HA_MAX_KEY_LENGTH + 24+ 6+6) +#define HA_MAX_KEY_BUFF (HA_MAX_KEY_LENGTH+HA_MAX_KEY_SEG*6+8+8) /* Limit max keys according to HA_MAX_POSSIBLE_KEY |