Commit e124882e authored by heikki@donna.mysql.fi's avatar heikki@donna.mysql.fi
Browse files

dict0mem.c, dict0dict.c, row0mysql.c, dict0mem.h: 

  Do less statistics calculations for tables
dict0mem.h, row0mysql.c:
  Make calculation of new statistics less frequent, because the statistics in 3.23.44 involves many random disk reads
parent 6a01d8bc

innobase/dict/dict0dict.c

+7 −3
Original line number Diff line number Diff line
@@ -455,7 +455,7 @@ dict_table_get( 
	mutex_exit(&(dict_sys->mutex));



	if (table != NULL) {

		if (table->stat_last_estimate_counter == (ulint)(-1)) {

	        if (!table->stat_initialized) {

			dict_update_statistics(table);

		}

	}
@@ -2578,6 +2578,8 @@ dict_update_statistics_low( 
	ulint		size;

	ulint		sum_of_index_sizes	= 0;



	printf("Updating statistics for table %s\n", table->name);



	/* Find out the sizes of the indexes and how many different values

	for the key they approximately have */
@@ -2614,7 +2616,9 @@ dict_update_statistics_low( 
	table->stat_sum_of_other_index_sizes = sum_of_index_sizes

						- index->stat_index_size;



	table->stat_last_estimate_counter = table->stat_modif_counter;

	table->stat_initialized = TRUE;



        table->stat_modified_counter = 0;

}



/*************************************************************************

innobase/dict/dict0mem.c

+2 −2
Original line number Diff line number Diff line
@@ -73,9 +73,9 @@ dict_mem_table_create( 


	table->does_not_fit_in_memory = FALSE;



	table->stat_last_estimate_counter = (ulint)(-1);

	table->stat_initialized = FALSE;



	table->stat_modif_counter = 0;

	table->stat_modified_counter = 0;

	

	mutex_create(&(table->autoinc_mutex));

	mutex_set_level(&(table->autoinc_mutex), SYNC_DICT_AUTOINC_MUTEX);

innobase/include/dict0mem.h

+9 −13
Original line number Diff line number Diff line
@@ -348,20 +348,20 @@ struct dict_table_struct{ 
				database pages */

	ulint		stat_sum_of_other_index_sizes;

				/* other indexes in database pages */

	ulint		stat_last_estimate_counter;

				/* when the estimates were last time

				calculated; a value (ulint)-1 denotes that

				they have not yet been calculated for this

				table (or the counter has wrapped over) */

	ulint		stat_modif_counter;

	ibool           stat_initialized; /* TRUE if statistics have

				been calculated the first time

			        after database startup or table creation */

	ulint		stat_modified_counter;

				/* when a row is inserted, updated, or deleted,

				we add the row length to this number; we

				calculate new estimates for the stat_...

				values for the table and the indexes at an

				interval of DICT_STAT_CALCULATE_INTERVAL,

				but for small tables more often, also

				interval of 2 GB or when about 1 / 16 of table

				has been modified; also

				when the estimate operation is called

				for MySQL SHOW TABLE STATUS; this counter

				for MySQL SHOW TABLE STATUS; the counter is

				reset to zero at statistics calculation;

				this counter

				is not protected by any latch, because this

				is only used for heuristics */

	/*----------------------*/
@@ -378,10 +378,6 @@ struct dict_table_struct{ 
};

#define	DICT_TABLE_MAGIC_N	76333786

					

/* Statistics are calculated at least with this interval; see the struct

above */

#define DICT_STAT_CALCULATE_INTERVAL	(UNIV_PAGE_SIZE * 8)

					

/* Data structure for a stored procedure */

struct dict_proc_struct{

	mem_heap_t*	heap;	/* memory heap */

innobase/row/row0mysql.c

+34 −9
Original line number Diff line number Diff line
@@ -432,19 +432,24 @@ row_update_statistics_if_needed( 
	row_prebuilt_t*	prebuilt)	/* in: prebuilt struct */

{

	ulint	counter;

	ulint	old_counter;

	

	counter = prebuilt->table->stat_modif_counter;

	counter = prebuilt->table->stat_modified_counter;



	counter += prebuilt->mysql_row_len;

	prebuilt->table->stat_modif_counter = counter;

	/* Since the physical size of an InnoDB row is bigger than the

	MySQL row len, we put a safety factor 2 below */



	old_counter = prebuilt->table->stat_last_estimate_counter;

	counter += 2 * prebuilt->mysql_row_len;



	if (counter - old_counter >= DICT_STAT_CALCULATE_INTERVAL

	    || counter - old_counter >=

		(UNIV_PAGE_SIZE

			* prebuilt->table->stat_clustered_index_size / 2)) {

	prebuilt->table->stat_modified_counter = counter;



	/* Calculate new statistics if 1 / 16 of table has been modified

	since the last time a statistics batch was run, or if

	stat_modified_counter > 2 000 000 000 (to avoid wrap-around) */



	if (counter > 2000000000

	    || ((ib_longlong)counter >

		(UNIV_PAGE_SIZE * prebuilt->table->stat_clustered_index_size)

		/ 16)) {



		dict_update_statistics(prebuilt->table);

	}
@@ -1019,6 +1024,26 @@ row_create_table_for_mysql( 
		os_event_set(srv_lock_timeout_thread_event);

	}



	keywordlen = ut_strlen("innodb_mem_validate");



	if (namelen >= keywordlen

		    && 0 == ut_memcmp(table->name + namelen - keywordlen,

 				"innodb_mem_validate", keywordlen)) {



	        /* We define here a debugging feature intended for

		developers */



	        printf("Validating InnoDB memory:\n"

		 "to use this feature you must compile InnoDB with\n"

		 "UNIV_MEM_DEBUG defined in univ.i and the server must be\n"

		 "quiet because allocation from a mem heap is not protected\n"

		       "by any semaphore.\n");



		ut_a(mem_validate());

		      

		printf("Memory validated\n");

	}



	/* Serialize data dictionary operations with dictionary mutex:

	no deadlocks can occur then in these operations */