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d00f19e832
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.
579 lines
16 KiB
Text
579 lines
16 KiB
Text
#In this test case we will check what will happen in the case of hash collision
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SET debug_dbug="d,same_long_unique_hash";
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create table t1(a blob unique);
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FLUSH STATUS;
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insert into t1 values('xyz');
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insert into t1 values('abc');
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insert into t1 values('sachin');
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insert into t1 values('sachin');
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ERROR 23000: Duplicate entry 'sachin' for key 'a'
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insert into t1 values('maria');
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insert into t1 values('maria');
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ERROR 23000: Duplicate entry 'maria' for key 'a'
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drop table t1;
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SHOW STATUS LIKE 'handler_read_next';
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Variable_name Value
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Handler_read_next 11
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SET debug_dbug="";
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create table t1(a blob unique);
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FLUSH STATUS;
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insert into t1 values('xyz');
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insert into t1 values('abc');
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insert into t1 values('sachin');
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insert into t1 values('sachin');
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ERROR 23000: Duplicate entry 'sachin' for key 'a'
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insert into t1 values('maria');
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insert into t1 values('maria');
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ERROR 23000: Duplicate entry 'maria' for key 'a'
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drop table t1;
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SHOW STATUS LIKE 'handler_read_next';
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Variable_name Value
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Handler_read_next 0
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SET debug_dbug="d,same_long_unique_hash";
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create table t1(a blob unique, b blob unique);
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insert into t1 values('xyz', 11);
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insert into t1 values('abc', 22);
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insert into t1 values('sachin', 1);
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insert into t1 values('sachin', 4);
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ERROR 23000: Duplicate entry 'sachin' for key 'a'
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insert into t1 values('maria', 2);
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insert into t1 values('maria', 3);
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ERROR 23000: Duplicate entry 'maria' for key 'a'
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drop table t1;
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create table t1(a blob , b blob , unique(a,b));
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insert into t1 values('xyz', 11);
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insert into t1 values('abc', 22);
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insert into t1 values('sachin', 1);
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insert into t1 values('sachin', 1);
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ERROR 23000: Duplicate entry 'sachin-1' for key 'a'
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insert into t1 values('maria', 2);
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insert into t1 values('maria', 2);
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ERROR 23000: Duplicate entry 'maria-2' for key 'a'
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drop table t1;
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##Internal State of long unique tables
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SET debug_dbug="d,print_long_unique_internal_state";
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create table t1 ( a blob unique);
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Warnings:
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Note 1 Printing Table state, It will print table fields, fields->offset,field->null_bit, field->null_pos and key_info ...
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Printing Table keyinfo
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table->s->reclength 19
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table->s->fields 2
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table->key_info[0] user_defined_key_parts = 1
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table->key_info[0] algorithm == HA_KEY_ALG_LONG_HASH = 1
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table->key_info[0] flags & HA_NOSAME = 0
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table->s->key_info[0] user_defined_key_parts = 1
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table->s->key_info[0] algorithm == HA_KEY_ALG_LONG_HASH = 1
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table->s->key_info[0] flags & HA_NOSAME = 1
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Printing table->key_info[0].key_part[0] info
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key_part->offset = 11
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key_part->field_name = DB_ROW_HASH_1
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key_part->length = 8
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key_part->null_bit = 2
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key_part->null_offset = 0
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Printing share->key_info[0].key_part[0] info
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key_part->offset = 1
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key_part->field_name = a
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key_part->length = 0
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key_part->null_bit = 1
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key_part->null_offset = 0
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Printing table->fields
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table->field[0]->field_name a
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table->field[0]->offset = 1
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table->field[0]->field_length = 10
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table->field[0]->null_pos wrt to record 0 = 0
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table->field[0]->null_bit_pos = 1
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table->field[1]->field_name DB_ROW_HASH_1
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table->field[1]->offset = 11
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table->field[1]->field_length = 8
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table->field[1]->null_pos wrt to record 0 = 0
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table->field[1]->null_bit_pos = 2
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SET debug_dbug="";
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drop table t1;
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SET debug_dbug="d,print_long_unique_internal_state";
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create table t1 ( a blob unique, b blob unique , c blob unique);
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Warnings:
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Note 1 Printing Table state, It will print table fields, fields->offset,field->null_bit, field->null_pos and key_info ...
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Printing Table keyinfo
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table->s->reclength 55
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table->s->fields 6
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table->key_info[0] user_defined_key_parts = 1
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table->key_info[0] algorithm == HA_KEY_ALG_LONG_HASH = 1
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table->key_info[0] flags & HA_NOSAME = 0
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table->s->key_info[0] user_defined_key_parts = 1
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table->s->key_info[0] algorithm == HA_KEY_ALG_LONG_HASH = 1
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table->s->key_info[0] flags & HA_NOSAME = 1
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Printing table->key_info[0].key_part[0] info
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key_part->offset = 31
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key_part->field_name = DB_ROW_HASH_1
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key_part->length = 8
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key_part->null_bit = 8
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key_part->null_offset = 0
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Printing share->key_info[0].key_part[0] info
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key_part->offset = 1
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key_part->field_name = a
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key_part->length = 0
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key_part->null_bit = 1
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key_part->null_offset = 0
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table->key_info[1] user_defined_key_parts = 1
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table->key_info[1] algorithm == HA_KEY_ALG_LONG_HASH = 1
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table->key_info[1] flags & HA_NOSAME = 0
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table->s->key_info[1] user_defined_key_parts = 1
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table->s->key_info[1] algorithm == HA_KEY_ALG_LONG_HASH = 1
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table->s->key_info[1] flags & HA_NOSAME = 1
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Printing table->key_info[1].key_part[0] info
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key_part->offset = 39
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key_part->field_name = DB_ROW_HASH_2
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key_part->length = 8
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key_part->null_bit = 16
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key_part->null_offset = 0
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Printing share->key_info[1].key_part[0] info
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key_part->offset = 11
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key_part->field_name = b
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key_part->length = 0
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key_part->null_bit = 2
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key_part->null_offset = 0
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table->key_info[2] user_defined_key_parts = 1
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table->key_info[2] algorithm == HA_KEY_ALG_LONG_HASH = 1
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table->key_info[2] flags & HA_NOSAME = 0
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table->s->key_info[2] user_defined_key_parts = 1
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table->s->key_info[2] algorithm == HA_KEY_ALG_LONG_HASH = 1
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table->s->key_info[2] flags & HA_NOSAME = 1
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Printing table->key_info[2].key_part[0] info
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key_part->offset = 47
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key_part->field_name = DB_ROW_HASH_3
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key_part->length = 8
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key_part->null_bit = 32
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key_part->null_offset = 0
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Printing share->key_info[2].key_part[0] info
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key_part->offset = 21
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key_part->field_name = c
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key_part->length = 0
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key_part->null_bit = 4
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key_part->null_offset = 0
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Printing table->fields
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table->field[0]->field_name a
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table->field[0]->offset = 1
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table->field[0]->field_length = 10
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table->field[0]->null_pos wrt to record 0 = 0
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table->field[0]->null_bit_pos = 1
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table->field[1]->field_name b
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table->field[1]->offset = 11
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table->field[1]->field_length = 10
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table->field[1]->null_pos wrt to record 0 = 0
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table->field[1]->null_bit_pos = 2
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table->field[2]->field_name c
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table->field[2]->offset = 21
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table->field[2]->field_length = 10
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table->field[2]->null_pos wrt to record 0 = 0
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table->field[2]->null_bit_pos = 4
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table->field[3]->field_name DB_ROW_HASH_1
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table->field[3]->offset = 31
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table->field[3]->field_length = 8
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table->field[3]->null_pos wrt to record 0 = 0
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table->field[3]->null_bit_pos = 8
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table->field[4]->field_name DB_ROW_HASH_2
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table->field[4]->offset = 39
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table->field[4]->field_length = 8
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table->field[4]->null_pos wrt to record 0 = 0
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table->field[4]->null_bit_pos = 16
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table->field[5]->field_name DB_ROW_HASH_3
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table->field[5]->offset = 47
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table->field[5]->field_length = 8
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table->field[5]->null_pos wrt to record 0 = 0
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table->field[5]->null_bit_pos = 32
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SET debug_dbug="";
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drop table t1;
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SET debug_dbug="d,print_long_unique_internal_state";
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create table t1 ( a blob , b blob , c blob , d blob , unique (a,b), unique(c, d));
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Warnings:
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Note 1 Printing Table state, It will print table fields, fields->offset,field->null_bit, field->null_pos and key_info ...
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Printing Table keyinfo
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table->s->reclength 57
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table->s->fields 6
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table->key_info[0] user_defined_key_parts = 1
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table->key_info[0] algorithm == HA_KEY_ALG_LONG_HASH = 1
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table->key_info[0] flags & HA_NOSAME = 0
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table->s->key_info[0] user_defined_key_parts = 2
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table->s->key_info[0] algorithm == HA_KEY_ALG_LONG_HASH = 1
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table->s->key_info[0] flags & HA_NOSAME = 1
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Printing table->key_info[0].key_part[0] info
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key_part->offset = 41
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key_part->field_name = DB_ROW_HASH_1
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key_part->length = 8
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key_part->null_bit = 16
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key_part->null_offset = 0
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Printing share->key_info[0].key_part[0] info
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key_part->offset = 1
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key_part->field_name = a
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key_part->length = 0
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key_part->null_bit = 1
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key_part->null_offset = 0
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Printing share->key_info[0].key_part[1] info
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key_part->offset = 11
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key_part->field_name = b
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key_part->length = 0
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key_part->null_bit = 2
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key_part->null_offset = 0
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table->key_info[1] user_defined_key_parts = 1
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table->key_info[1] algorithm == HA_KEY_ALG_LONG_HASH = 1
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table->key_info[1] flags & HA_NOSAME = 0
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table->s->key_info[1] user_defined_key_parts = 2
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table->s->key_info[1] algorithm == HA_KEY_ALG_LONG_HASH = 1
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table->s->key_info[1] flags & HA_NOSAME = 1
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Printing table->key_info[1].key_part[0] info
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key_part->offset = 49
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key_part->field_name = DB_ROW_HASH_2
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key_part->length = 8
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key_part->null_bit = 32
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key_part->null_offset = 0
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Printing share->key_info[1].key_part[0] info
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key_part->offset = 21
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key_part->field_name = c
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key_part->length = 0
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key_part->null_bit = 4
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key_part->null_offset = 0
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Printing share->key_info[1].key_part[1] info
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key_part->offset = 31
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key_part->field_name = d
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key_part->length = 0
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key_part->null_bit = 8
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key_part->null_offset = 0
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Printing table->fields
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table->field[0]->field_name a
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table->field[0]->offset = 1
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table->field[0]->field_length = 10
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table->field[0]->null_pos wrt to record 0 = 0
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table->field[0]->null_bit_pos = 1
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table->field[1]->field_name b
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table->field[1]->offset = 11
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table->field[1]->field_length = 10
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table->field[1]->null_pos wrt to record 0 = 0
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table->field[1]->null_bit_pos = 2
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table->field[2]->field_name c
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table->field[2]->offset = 21
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table->field[2]->field_length = 10
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table->field[2]->null_pos wrt to record 0 = 0
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table->field[2]->null_bit_pos = 4
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table->field[3]->field_name d
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table->field[3]->offset = 31
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table->field[3]->field_length = 10
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table->field[3]->null_pos wrt to record 0 = 0
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table->field[3]->null_bit_pos = 8
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table->field[4]->field_name DB_ROW_HASH_1
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table->field[4]->offset = 41
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table->field[4]->field_length = 8
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table->field[4]->null_pos wrt to record 0 = 0
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table->field[4]->null_bit_pos = 16
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table->field[5]->field_name DB_ROW_HASH_2
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table->field[5]->offset = 49
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table->field[5]->field_length = 8
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table->field[5]->null_pos wrt to record 0 = 0
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table->field[5]->null_bit_pos = 32
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SET debug_dbug="";
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drop table t1;
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SET debug_dbug="d,print_long_unique_internal_state";
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create table t1(a int primary key, b blob unique , c blob unique not null);
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Warnings:
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Note 1 Printing Table state, It will print table fields, fields->offset,field->null_bit, field->null_pos and key_info ...
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Printing Table keyinfo
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table->s->reclength 41
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table->s->fields 5
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table->key_info[0] user_defined_key_parts = 1
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table->key_info[0] algorithm == HA_KEY_ALG_LONG_HASH = 0
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table->key_info[0] flags & HA_NOSAME = 1
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table->s->key_info[0] user_defined_key_parts = 1
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table->s->key_info[0] algorithm == HA_KEY_ALG_LONG_HASH = 0
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table->s->key_info[0] flags & HA_NOSAME = 1
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Printing table->key_info[0].key_part[0] info
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key_part->offset = 1
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key_part->field_name = a
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key_part->length = 4
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key_part->null_bit = 0
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key_part->null_offset = 0
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Printing share->key_info[0].key_part[0] info
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key_part->offset = 1
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key_part->field_name = a
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key_part->length = 4
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key_part->null_bit = 0
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key_part->null_offset = 0
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table->key_info[1] user_defined_key_parts = 1
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table->key_info[1] algorithm == HA_KEY_ALG_LONG_HASH = 1
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table->key_info[1] flags & HA_NOSAME = 0
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table->s->key_info[1] user_defined_key_parts = 1
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table->s->key_info[1] algorithm == HA_KEY_ALG_LONG_HASH = 1
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table->s->key_info[1] flags & HA_NOSAME = 1
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Printing table->key_info[1].key_part[0] info
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key_part->offset = 25
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key_part->field_name = DB_ROW_HASH_1
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key_part->length = 8
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key_part->null_bit = 2
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key_part->null_offset = 0
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Printing share->key_info[1].key_part[0] info
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key_part->offset = 5
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key_part->field_name = b
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key_part->length = 0
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key_part->null_bit = 1
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key_part->null_offset = 0
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table->key_info[2] user_defined_key_parts = 1
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table->key_info[2] algorithm == HA_KEY_ALG_LONG_HASH = 1
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table->key_info[2] flags & HA_NOSAME = 0
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table->s->key_info[2] user_defined_key_parts = 1
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table->s->key_info[2] algorithm == HA_KEY_ALG_LONG_HASH = 1
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table->s->key_info[2] flags & HA_NOSAME = 1
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Printing table->key_info[2].key_part[0] info
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key_part->offset = 33
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key_part->field_name = DB_ROW_HASH_2
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key_part->length = 8
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key_part->null_bit = 0
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key_part->null_offset = 0
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Printing share->key_info[2].key_part[0] info
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key_part->offset = 15
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key_part->field_name = c
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key_part->length = 0
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key_part->null_bit = 0
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key_part->null_offset = 0
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Printing table->fields
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table->field[0]->field_name a
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table->field[0]->offset = 1
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table->field[0]->field_length = 4
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table->field[0]->null_pos wrt to record 0 = -1
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table->field[0]->null_bit_pos = 0
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table->field[1]->field_name b
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table->field[1]->offset = 5
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table->field[1]->field_length = 10
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table->field[1]->null_pos wrt to record 0 = 0
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table->field[1]->null_bit_pos = 1
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table->field[2]->field_name c
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table->field[2]->offset = 15
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table->field[2]->field_length = 10
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table->field[2]->null_pos wrt to record 0 = -1
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table->field[2]->null_bit_pos = 0
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table->field[3]->field_name DB_ROW_HASH_1
|
|
table->field[3]->offset = 25
|
|
table->field[3]->field_length = 8
|
|
table->field[3]->null_pos wrt to record 0 = 0
|
|
table->field[3]->null_bit_pos = 2
|
|
|
|
table->field[4]->field_name DB_ROW_HASH_2
|
|
table->field[4]->offset = 33
|
|
table->field[4]->field_length = 8
|
|
table->field[4]->null_pos wrt to record 0 = -1
|
|
table->field[4]->null_bit_pos = 0
|
|
|
|
SET debug_dbug="";
|
|
drop table t1;
|
|
##Using hash
|
|
SET debug_dbug="d,print_long_unique_internal_state";
|
|
create table t1(a int ,b int , c int, unique(a, b, c) using hash);
|
|
Warnings:
|
|
Note 1 Printing Table state, It will print table fields, fields->offset,field->null_bit, field->null_pos and key_info ...
|
|
|
|
Printing Table keyinfo
|
|
|
|
table->s->reclength 21
|
|
table->s->fields 4
|
|
|
|
table->key_info[0] user_defined_key_parts = 1
|
|
table->key_info[0] algorithm == HA_KEY_ALG_LONG_HASH = 1
|
|
table->key_info[0] flags & HA_NOSAME = 0
|
|
|
|
table->s->key_info[0] user_defined_key_parts = 3
|
|
table->s->key_info[0] algorithm == HA_KEY_ALG_LONG_HASH = 1
|
|
table->s->key_info[0] flags & HA_NOSAME = 1
|
|
|
|
Printing table->key_info[0].key_part[0] info
|
|
key_part->offset = 13
|
|
key_part->field_name = DB_ROW_HASH_1
|
|
key_part->length = 8
|
|
key_part->null_bit = 16
|
|
key_part->null_offset = 0
|
|
|
|
Printing share->key_info[0].key_part[0] info
|
|
key_part->offset = 1
|
|
key_part->field_name = a
|
|
key_part->length = 4
|
|
key_part->null_bit = 2
|
|
key_part->null_offset = 0
|
|
|
|
Printing share->key_info[0].key_part[1] info
|
|
key_part->offset = 5
|
|
key_part->field_name = b
|
|
key_part->length = 4
|
|
key_part->null_bit = 4
|
|
key_part->null_offset = 0
|
|
|
|
Printing share->key_info[0].key_part[2] info
|
|
key_part->offset = 9
|
|
key_part->field_name = c
|
|
key_part->length = 4
|
|
key_part->null_bit = 8
|
|
key_part->null_offset = 0
|
|
|
|
Printing table->fields
|
|
|
|
table->field[0]->field_name a
|
|
table->field[0]->offset = 1
|
|
table->field[0]->field_length = 4
|
|
table->field[0]->null_pos wrt to record 0 = 0
|
|
table->field[0]->null_bit_pos = 2
|
|
|
|
table->field[1]->field_name b
|
|
table->field[1]->offset = 5
|
|
table->field[1]->field_length = 4
|
|
table->field[1]->null_pos wrt to record 0 = 0
|
|
table->field[1]->null_bit_pos = 4
|
|
|
|
table->field[2]->field_name c
|
|
table->field[2]->offset = 9
|
|
table->field[2]->field_length = 4
|
|
table->field[2]->null_pos wrt to record 0 = 0
|
|
table->field[2]->null_bit_pos = 8
|
|
|
|
table->field[3]->field_name DB_ROW_HASH_1
|
|
table->field[3]->offset = 13
|
|
table->field[3]->field_length = 8
|
|
table->field[3]->null_pos wrt to record 0 = 0
|
|
table->field[3]->null_bit_pos = 16
|
|
|
|
SET debug_dbug="";
|
|
drop table t1;
|
|
##Using hash but with memory engine so no long unique column
|
|
SET debug_dbug="d,print_long_unique_internal_state";
|
|
create table t1(a int ,b int , c int, unique(a, b, c) using hash) engine=memory;
|
|
Warnings:
|
|
Note 1 Printing Table state, It will print table fields, fields->offset,field->null_bit, field->null_pos and key_info ...
|
|
|
|
Printing Table keyinfo
|
|
|
|
table->s->reclength 13
|
|
table->s->fields 3
|
|
|
|
table->key_info[0] user_defined_key_parts = 3
|
|
table->key_info[0] algorithm == HA_KEY_ALG_LONG_HASH = 0
|
|
table->key_info[0] flags & HA_NOSAME = 1
|
|
|
|
table->s->key_info[0] user_defined_key_parts = 3
|
|
table->s->key_info[0] algorithm == HA_KEY_ALG_LONG_HASH = 0
|
|
table->s->key_info[0] flags & HA_NOSAME = 1
|
|
|
|
Printing table->key_info[0].key_part[0] info
|
|
key_part->offset = 1
|
|
key_part->field_name = a
|
|
key_part->length = 4
|
|
key_part->null_bit = 2
|
|
key_part->null_offset = 0
|
|
|
|
Printing share->key_info[0].key_part[0] info
|
|
key_part->offset = 1
|
|
key_part->field_name = a
|
|
key_part->length = 4
|
|
key_part->null_bit = 2
|
|
key_part->null_offset = 0
|
|
|
|
Printing share->key_info[0].key_part[1] info
|
|
key_part->offset = 5
|
|
key_part->field_name = b
|
|
key_part->length = 4
|
|
key_part->null_bit = 4
|
|
key_part->null_offset = 0
|
|
|
|
Printing share->key_info[0].key_part[2] info
|
|
key_part->offset = 9
|
|
key_part->field_name = c
|
|
key_part->length = 4
|
|
key_part->null_bit = 8
|
|
key_part->null_offset = 0
|
|
|
|
Printing table->fields
|
|
|
|
table->field[0]->field_name a
|
|
table->field[0]->offset = 1
|
|
table->field[0]->field_length = 4
|
|
table->field[0]->null_pos wrt to record 0 = 0
|
|
table->field[0]->null_bit_pos = 2
|
|
|
|
table->field[1]->field_name b
|
|
table->field[1]->offset = 5
|
|
table->field[1]->field_length = 4
|
|
table->field[1]->null_pos wrt to record 0 = 0
|
|
table->field[1]->null_bit_pos = 4
|
|
|
|
table->field[2]->field_name c
|
|
table->field[2]->offset = 9
|
|
table->field[2]->field_length = 4
|
|
table->field[2]->null_pos wrt to record 0 = 0
|
|
table->field[2]->null_bit_pos = 8
|
|
|
|
SET debug_dbug="";
|
|
drop table t1;
|