Sachin d00f19e832 MDEV-371 Unique Index for long columns ... This patch implements engine independent unique hash index. Usage:- Unique HASH index can be created automatically for blob/varchar/test column whose key length > handler->max_key_length() or it can be explicitly specified. Automatic Creation:- Create TABLE t1 (a blob unique); Explicit Creation:- Create TABLE t1 (a int , unique(a) using HASH); Internal KEY_PART Representations:- Long unique key_info will have 2 representations. (lets understand this with an example create table t1(a blob, b blob , unique(a, b)); ) 1. User Given Representation:- key_info->key_part array will be similar to what user has defined. So in case of example it will have 2 key_parts (a, b) 2. Storage Engine Representation:- In this case there will be only one key_part and it will point to HASH_FIELD. This key_part will be always after user defined key_parts. So:- User Given Representation [a] [b] [hash_key_part] key_info->key_part ----^ Storage Engine Representation [a] [b] [hash_key_part] key_info->key_part ------------^ Table->s->key_info will have User Given Representation, While table->key_info will have Storage Engine Representation.Representation can be changed into each other by calling re/setup_keyinfo_hash function. Working:- 1. So when user specifies HASH_INDEX or key_length is > handler->max_key_length(), In mysql_prepare_create_table One extra vfield is added (for each long unique key). And key_info->algorithm is set to HA_KEY_ALG_LONG_HASH. 2. In init_from_binary_frm_image values for hash_keypart is set (like fieldnr , field and flags) 3. In parse_vcol_defs, HASH_FIELD->vcol_info is created. Item_func_hash is used with list of Item_fields, When Explicit length is given by user then Item_left is used to concatenate Item_field values. 4. In ha_write_row/ha_update_row check_duplicate_long_entry_key is called which will create the hash key from table->record[0] and then call ha_index_read_map , if we found duplicated hash , we will compare the result field by field.		2019-02-22 00:35:40 +01:00
..
atomic
mysql
aria_backup.h
big_endian.h
byte_order_generic.h
byte_order_generic_x86.h
byte_order_generic_x86_64.h
CMakeLists.txt
decimal.h
dur_prop.h
errmsg.h
ft_global.h
handler_ername.h
handler_state.h
hash.h
heap.h
json_lib.h
keycache.h
lf.h
little_endian.h
m_ctype.h
m_string.h
ma_dyncol.h
maria.h
my_alarm.h
my_alloc.h
my_atomic.h
my_attribute.h
my_base.h
my_bit.h
my_bitmap.h
my_byteorder.h
my_check_opt.h
my_compare.h
my_compiler.h
my_context.h
my_counter.h
my_cpu.h
my_crypt.h
my_dbug.h
my_decimal_limits.h
my_default.h
my_dir.h
my_getopt.h
my_global.h
my_handler_errors.h
my_libwrap.h
my_list.h
my_md5.h
my_net.h
my_nosys.h
my_pthread.h
my_rdtsc.h
my_rnd.h
my_service_manager.h
my_stacktrace.h
my_sys.h
my_time.h
my_tree.h
my_uctype.h
my_user.h
my_valgrind.h
my_xml.h
myisam.h
myisamchk.h
myisammrg.h
myisampack.h
mysql.h
mysql.h.pp
mysql_async.h
mysql_com.h
mysql_com_server.h
mysql_embed.h
mysql_time.h
mysql_version.h.in
mysqld_default_groups.h
mysys_err.h
pack.h
password.h
probes_mysql.d.base
probes_mysql.h
probes_mysql_nodtrace.h.in
queues.h
rijndael.h
service_versions.h
source_revision.h.in
sql_common.h
ssl_compat.h
sslopt-case.h
sslopt-longopts.h
sslopt-vars.h
t_ctype.h
thr_alarm.h
thr_lock.h
thr_timer.h
thread_pool_priv.h
typelib.h
violite.h
waiting_threads.h
welcome_copyright_notice.h
wqueue.h
wsrep.h