diff options
| -rw-r--r-- | sql/structs.h | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/sql/structs.h b/sql/structs.h index 081ada88bf7..2037496635a 100644 --- a/sql/structs.h +++ b/sql/structs.h @@ -70,7 +70,13 @@ typedef struct st_key_part_info { /* Info about a key part */ Field *field; uint offset; /* offset in record (from 0) */ uint null_offset; /* Offset to null_bit in record */ - uint16 length; /* Length of key_part */ + uint16 length; /* Length of keypart value in bytes */ + /* + Number of bytes required to store the keypart value. This may be + different from the "length" field as it also counts + - possible NULL-flag byte (see HA_KEY_NULL_LENGTH) + - possible HA_KEY_BLOB_LENGTH bytes needed to store actual value length. + */ uint16 store_length; uint16 key_type; uint16 fieldnr; /* Fieldnum in UNIREG */ |