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Commit e50acec9 authored by marko's avatar marko
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Remove dict_col_t::hash, dict_col_t::table, 

dict_sys->col_hash, and DICT_POOL_PER_COL_HASH.  (Bug #20877)

The col->table pointer was only needed for maintaining a hash table of
all defined columns in all tables.  The hash table was only looked up
in dict_index_find_cols().  Removing the col->hash and col->table
pointers reduces the size of a table column by two machine words
(usually 8 or 16 bytes).

dict_col_add_to_cache(), dict_col_reposition_in_cache(),
dict_col_remove_from_cache(): Remove.  These only updated dict_sys->col_hash.

dict_index_find_cols(): Use a linear search instead of the hash table.
The time complexity is affected, but this function is only invoked by
dict_index_add_to_cache(), and we only search the columns of a single
table (typically at most a few dozen) as opposed to all columns of all
tables.
parent 18df0db0
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Inline Side-by-side
Showing with 13 additions and 161 deletions
dict/dict0dict.c
View file @ e50acec9
......@@ -48,8 +48,6 @@ rw_lock_t dict_operation_lock; /* table create, drop, etc. reserve
creating a table or index object */
#define DICT_POOL_PER_TABLE_HASH 512 /* buffer pool max size per table
hash table fixed size in bytes */
#define DICT_POOL_PER_COL_HASH 128 /* buffer pool max size per column
hash table fixed size in bytes */
#define DICT_POOL_PER_VARYING 4 /* buffer pool max size per data
dictionary varying size in bytes */
......@@ -129,32 +127,6 @@ innobase_get_charset(
void* mysql_thd); /* in: MySQL thread handle */
#endif /* !UNIV_HOTBACKUP */
/**************************************************************************
Adds a column to the data dictionary hash table. */
static
void
dict_col_add_to_cache(
/*==================*/
dict_table_t* table, /* in: table */
dict_col_t* col); /* in: column */
/**************************************************************************
Repositions a column in the data dictionary hash table when the table name
changes. */
static
void
dict_col_reposition_in_cache(
/*=========================*/
dict_table_t* table, /* in: table */
dict_col_t* col, /* in: column */
const char* new_name); /* in: new table name */
/**************************************************************************
Removes a column from the data dictionary hash table. */
static
void
dict_col_remove_from_cache(
/*=======================*/
dict_table_t* table, /* in: table */
dict_col_t* col); /* in: column */
/**************************************************************************
Removes an index from the dictionary cache. */
static
......@@ -174,7 +146,7 @@ dict_index_copy(
ulint start, /* in: first position to copy */
ulint end); /* in: last position to copy */
/***********************************************************************
Tries to find column names for the index in the column hash table and
Tries to find column names for the index and
sets the col field of the index. */
static
ibool
......@@ -774,9 +746,6 @@ dict_init(void)
dict_sys->table_id_hash = hash_create(buf_pool_get_max_size()
/ (DICT_POOL_PER_TABLE_HASH
* UNIV_WORD_SIZE));
dict_sys->col_hash = hash_create(buf_pool_get_max_size()
/ (DICT_POOL_PER_COL_HASH
* UNIV_WORD_SIZE));
dict_sys->size = 0;
UT_LIST_INIT(dict_sys->table_LRU);
......@@ -941,11 +910,6 @@ dict_table_add_to_cache(
ut_a(table2 == NULL);
}
/* Add the columns to the column hash table */
for (i = 0; i < table->n_cols; i++) {
dict_col_add_to_cache(table, dict_table_get_nth_col(table, i));
}
/* Add table to hash table of tables */
HASH_INSERT(dict_table_t, name_hash, dict_sys->table_hash, fold,
table);
......@@ -1013,7 +977,6 @@ dict_table_rename_in_cache(
ulint old_size;
char* old_name;
ibool success;
ulint i;
ut_ad(table);
#ifdef UNIV_SYNC_DEBUG
......@@ -1060,15 +1023,6 @@ dict_table_rename_in_cache(
}
}
/* Reposition the columns in the column hash table; they are hashed
according to the pair (table name, column name) */
for (i = 0; i < table->n_cols; i++) {
dict_col_reposition_in_cache(table,
dict_table_get_nth_col(table, i),
new_name);
}
/* Remove table from the hash tables of tables */
HASH_DELETE(dict_table_t, name_hash, dict_sys->table_hash,
ut_fold_string(table->name), table);
......@@ -1258,7 +1212,6 @@ dict_table_remove_from_cache(
dict_foreign_t* foreign;
dict_index_t* index;
ulint size;
ulint i;
ut_ad(table);
#ifdef UNIV_SYNC_DEBUG
......@@ -1299,12 +1252,6 @@ dict_table_remove_from_cache(
index = UT_LIST_GET_LAST(table->indexes);
}
/* Remove the columns of the table from the cache */
for (i = 0; i < table->n_cols; i++) {
dict_col_remove_from_cache(table,
dict_table_get_nth_col(table, i));
}
/* Remove table from the hash tables of tables */
HASH_DELETE(dict_table_t, name_hash, dict_sys->table_hash,
ut_fold_string(table->name), table);
......@@ -1323,92 +1270,6 @@ dict_table_remove_from_cache(
dict_mem_table_free(table);
}
/**************************************************************************
Adds a column to the data dictionary hash table. */
static
void
dict_col_add_to_cache(
/*==================*/
dict_table_t* table, /* in: table */
dict_col_t* col) /* in: column */
{
ulint fold;
ut_ad(table && col);
#ifdef UNIV_SYNC_DEBUG
ut_ad(mutex_own(&(dict_sys->mutex)));
#endif /* UNIV_SYNC_DEBUG */
ut_ad(table->magic_n == DICT_TABLE_MAGIC_N);
fold = ut_fold_ulint_pair(ut_fold_string(table->name),
ut_fold_string(col->name));
/* Look for a column with same table name and column name: error */
{
dict_col_t* col2;
HASH_SEARCH(hash, dict_sys->col_hash, fold, col2,
(ut_strcmp(col->name, col2->name) == 0)
&& (ut_strcmp((col2->table)->name, table->name)
== 0));
ut_a(col2 == NULL);
}
HASH_INSERT(dict_col_t, hash, dict_sys->col_hash, fold, col);
}
/**************************************************************************
Removes a column from the data dictionary hash table. */
static
void
dict_col_remove_from_cache(
/*=======================*/
dict_table_t* table, /* in: table */
dict_col_t* col) /* in: column */
{
ulint fold;
ut_ad(table && col);
#ifdef UNIV_SYNC_DEBUG
ut_ad(mutex_own(&(dict_sys->mutex)));
#endif /* UNIV_SYNC_DEBUG */
ut_ad(table->magic_n == DICT_TABLE_MAGIC_N);
fold = ut_fold_ulint_pair(ut_fold_string(table->name),
ut_fold_string(col->name));
HASH_DELETE(dict_col_t, hash, dict_sys->col_hash, fold, col);
}
/**************************************************************************
Repositions a column in the data dictionary hash table when the table name
changes. */
static
void
dict_col_reposition_in_cache(
/*=========================*/
dict_table_t* table, /* in: table */
dict_col_t* col, /* in: column */
const char* new_name) /* in: new table name */
{
ulint fold;
ut_ad(table && col);
#ifdef UNIV_SYNC_DEBUG
ut_ad(mutex_own(&(dict_sys->mutex)));
#endif /* UNIV_SYNC_DEBUG */
ut_ad(table->magic_n == DICT_TABLE_MAGIC_N);
fold = ut_fold_ulint_pair(ut_fold_string(table->name),
ut_fold_string(col->name));
HASH_DELETE(dict_col_t, hash, dict_sys->col_hash, fold, col);
fold = ut_fold_ulint_pair(ut_fold_string(new_name),
ut_fold_string(col->name));
HASH_INSERT(dict_col_t, hash, dict_sys->col_hash, fold, col);
}
/********************************************************************
If the given column name is reserved for InnoDB system columns, return
TRUE. */
......@@ -1606,7 +1467,7 @@ dict_index_remove_from_cache(
}
/***********************************************************************
Tries to find column names for the index in the column hash table and
Tries to find column names for the index and
sets the col field of the index. */
static
ibool
......@@ -1616,9 +1477,6 @@ dict_index_find_cols(
dict_table_t* table, /* in: table */
dict_index_t* index) /* in: index */
{
dict_col_t* col;
dict_field_t* field;
ulint fold;
ulint i;
ut_ad(table && index);
......@@ -1628,23 +1486,21 @@ dict_index_find_cols(
#endif /* UNIV_SYNC_DEBUG */
for (i = 0; i < index->n_fields; i++) {
field = dict_index_get_nth_field(index, i);
fold = ut_fold_ulint_pair(ut_fold_string(table->name),
ut_fold_string(field->name));
HASH_SEARCH(hash, dict_sys->col_hash, fold, col,
(ut_strcmp(col->name, field->name) == 0)
&& (ut_strcmp((col->table)->name, table->name)
== 0));
if (col == NULL) {
ulint j;
dict_field_t* field = dict_index_get_nth_field(index, i);
return(FALSE);
} else {
for (j = 0; j < table->n_cols; j++) {
dict_col_t* col = dict_table_get_nth_col(table, j);
if (!strcmp(col->name, field->name)) {
field->col = col;
goto found;
}
}
return(FALSE);
found: ;
}
return(TRUE);
}
......
dict/dict0mem.c
View file @ e50acec9
......@@ -134,7 +134,6 @@ dict_mem_table_add_col(
col->ind = table->n_def - 1;
col->name = mem_heap_strdup(table->heap, name);
col->table = table;
col->ord_part = 0;
col->clust_pos = REC_MAX_N_FIELDS;
......
include/dict0dict.h
View file @ e50acec9
......@@ -943,7 +943,6 @@ struct dict_sys_struct{
on name */
hash_table_t* table_id_hash; /* hash table of the tables, based
on id */
hash_table_t* col_hash; /* hash table of the columns */
UT_LIST_BASE_NODE_T(dict_table_t)
table_LRU; /* LRU list of tables */
ulint size; /* varying space in bytes occupied
......
include/dict0mem.h
View file @ e50acec9
......@@ -121,7 +121,6 @@ dict_mem_foreign_create(void);
/* Data structure for a column in a table */
struct dict_col_struct{
hash_node_t hash; /* hash chain node */
ulint ind:10; /* table column position (they are numbered
starting from 0) */
ulint clust_pos:10;/* position of the column in the
......@@ -130,7 +129,6 @@ struct dict_col_struct{
appears in ordering fields of an index */
const char* name; /* name */
dtype_t type; /* data type */
dict_table_t* table; /* back pointer to table of this column */
};
/* DICT_MAX_INDEX_COL_LEN is measured in bytes and is the max index column
......
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