Commit 71fdef4d authored by unknown's avatar unknown
Browse files

BUG#9622, stage 2, work together with fix for BUG#12232: 

added "nulls_ignored" index statistics collection method for MyISAM tables.
(notification trigger: this is about BUG#9622).


include/my_base.h:
  BUG#9622: Added MI_STATS_METHOD_IGNORE_NULLS statistics collection method:
  Added SEARCH_RETURN_B_POS flag for ha_key_cmp()
include/my_handler.h:
  BUG#9622: Added MI_STATS_METHOD_IGNORE_NULLS statistics collection method: added ha_find_null()
include/myisam.h:
  BUG#9622: Added MI_STATS_METHOD_IGNORE_NULLS statistics collection method.
myisam/mi_check.c:
  BUG#9622: Added MI_STATS_METHOD_IGNORE_NULLS statistics collection method, added 
   mi_collect_stats_*(), updated update_key_parts() to deal with all 3 methods.
myisam/myisamchk.c:
  BUG#9622: Added nulls_ignored index statistics collection method for MyISAM
myisam/myisamdef.h:
  BUG#9622: Added MI_STATS_METHOD_IGNORE_NULLS statistics collection method.
myisam/sort.c:
  BUG#9622: Added MI_STATS_METHOD_IGNORE_NULLS statistics collection method.
mysql-test/r/myisam.result:
  Testcase for BUG9622
mysql-test/t/myisam.test:
  Testcase for BUG9622
mysys/my_handler.c:
  BUG#9622: ha_key_cmp() now supports new SEARCH_RETURN_B_POS flag, added ha_find_null()
sql/ha_myisam.cc:
  BUG#9622: Added MI_STATS_METHOD_IGNORE_NULLS statistics collection method.
sql/mysqld.cc:
  BUG#9622: Added MI_STATS_METHOD_IGNORE_NULLS statistics collection method.
parent 0c16a7cc

include/my_base.h

+2 −0
Original line number Diff line number Diff line
@@ -319,6 +319,8 @@ enum ha_base_keytype { 
#define SEARCH_NULL_ARE_EQUAL 32768	/* NULL in keys are equal */

#define SEARCH_NULL_ARE_NOT_EQUAL 65536	/* NULL in keys are not equal */



#define SEARCH_RETURN_B_POS (65536*2)   /* see ha_key_cmp for description */



	/* bits in opt_flag */

#define QUICK_USED	1

#define READ_CACHE_USED	2

include/my_handler.h

+2 −0
Original line number Diff line number Diff line
@@ -63,4 +63,6 @@ extern int ha_key_cmp(register HA_KEYSEG *keyseg, register uchar *a, 
		      register uchar *b, uint key_length, uint nextflag,

		      uint *diff_pos);



extern HA_KEYSEG *ha_find_null(HA_KEYSEG *keyseg, uchar *a);



#endif /* _my_handler_h */

include/myisam.h

+12 −2
Original line number Diff line number Diff line
@@ -322,7 +322,9 @@ typedef enum 
  /* Treat NULLs as inequal when collecting statistics (default for 4.1/5.0) */

  MI_STATS_METHOD_NULLS_NOT_EQUAL,

  /* Treat NULLs as equal when collecting statistics (like 4.0 did) */

  MI_STATS_METHOD_NULLS_EQUAL

  MI_STATS_METHOD_NULLS_EQUAL,

  /* Ignore NULLs - count tuples without NULLs only */

  MI_STATS_METHOD_IGNORE_NULLS

} enum_mi_stats_method;



typedef struct st_mi_check_param
@@ -349,7 +351,14 @@ typedef struct st_mi_check_param 
  int tmpfile_createflag;

  myf myf_rw;

  IO_CACHE read_cache;

  

  /* 

    The next two are used to collect statistics, see update_key_parts for

    description.

  */

  ulonglong unique_count[MI_MAX_KEY_SEG+1];

  ulonglong notnull_count[MI_MAX_KEY_SEG+1];

  

  ha_checksum key_crc[MI_MAX_POSSIBLE_KEY];

  ulong rec_per_key_part[MI_MAX_KEY_SEG*MI_MAX_POSSIBLE_KEY];

  void *thd;
@@ -409,7 +418,8 @@ void update_auto_increment_key(MI_CHECK *param, MI_INFO *info, 
			       my_bool repair);

int update_state_info(MI_CHECK *param, MI_INFO *info,uint update);

void update_key_parts(MI_KEYDEF *keyinfo, ulong *rec_per_key_part,

			     ulonglong *unique, ulonglong records);

                      ulonglong *unique, ulonglong *notnull, 

                      ulonglong records);

int filecopy(MI_CHECK *param, File to,File from,my_off_t start,

	     my_off_t length, const char *type);

int movepoint(MI_INFO *info,byte *record,my_off_t oldpos,

myisam/mi_check.c

+161 −15
Original line number Diff line number Diff line
@@ -391,7 +391,10 @@ int chk_key(MI_CHECK *param, register MI_INFO *info) 
    found_keys++;



    param->record_checksum=init_checksum;

    

    bzero((char*) &param->unique_count,sizeof(param->unique_count));

    bzero((char*) &param->notnull_count,sizeof(param->notnull_count));



    if ((!(param->testflag & T_SILENT)))

      printf ("- check data record references index: %d\n",key+1);

    if (keyinfo->flag & HA_FULLTEXT)
@@ -496,6 +499,8 @@ int chk_key(MI_CHECK *param, register MI_INFO *info) 


    if (param->testflag & T_STATISTICS)

      update_key_parts(keyinfo, rec_per_key_part, param->unique_count,

                       param->stats_method == MI_STATS_METHOD_IGNORE_NULLS?

                       param->notnull_count: NULL, 

                       (ulonglong)info->state->records);

  }

  if (param->testflag & T_INFO)
@@ -552,6 +557,87 @@ static int chk_index_down(MI_CHECK *param, MI_INFO *info, MI_KEYDEF *keyinfo, 
  return 1;

}





/*

  "Ignore NULLs" statistics collection method: process first index tuple.



  SYNOPSIS

    mi_collect_stats_nonulls_first()

      keyseg   IN     Array of key part descriptions

      notnull  INOUT  Array, notnull[i] = (number of {keypart1...keypart_i}

                                           tuples that don't contain NULLs)

      key      IN     Key values tuple



  DESCRIPTION

    Process the first index tuple - find out which prefix tuples don't

    contain NULLs, and update the array of notnull counters accordingly.

*/



static

void mi_collect_stats_nonulls_first(HA_KEYSEG *keyseg, ulonglong *notnull,

                                    uchar *key)

{

  uint first_null, kp;

  first_null= ha_find_null(keyseg, key) - keyseg;

  /*

    All prefix tuples that don't include keypart_{first_null} are not-null

    tuples (and all others aren't), increment counters for them.

  */

  for (kp= 0; kp < first_null; kp++)

    notnull[kp]++;

}





/*

  "Ignore NULLs" statistics collection method: process next index tuple.



  SYNOPSIS

    mi_collect_stats_nonulls_next()

      keyseg   IN     Array of key part descriptions

      notnull  INOUT  Array, notnull[i] = (number of {keypart1...keypart_i}

                                           tuples that don't contain NULLs)

      prev_key IN     Previous key values tuple

      last_key IN     Next key values tuple



  DESCRIPTION

    Process the next index tuple:

    1. Find out which prefix tuples of last_key don't contain NULLs, and

       update the array of notnull counters accordingly.

    2. Find the first keypart number where the tuples are different(A), or

       last_key has NULL value (B), and return it, so caller can count

       number of unique tuples for each key prefix. We don't need (B) to be

       counted, and that is compensated back in update_key_parts().



  RETURN

    1 + number of first keypart where values differ or last_key tuple has NULL

*/



static

int mi_collect_stats_nonulls_next(HA_KEYSEG *keyseg, ulonglong *notnull,

                                  uchar *prev_key, uchar *last_key)

{

  uint diffs[2];

  uint first_null_seg, kp;



  /* Find first keypart where values are different or either of them is NULL */

  ha_key_cmp(keyseg, prev_key, last_key, USE_WHOLE_KEY, 

             SEARCH_FIND | SEARCH_NULL_ARE_NOT_EQUAL | SEARCH_RETURN_B_POS,

             diffs);

  HA_KEYSEG *seg= keyseg + diffs[0] - 1;

  /* Find first NULL in last_key */

  first_null_seg= ha_find_null(seg, last_key + diffs[1]) - keyseg;

  for (kp= 0; kp < first_null_seg; kp++)

    notnull[kp]++;



  /* 

    Return 1+ number of first key part where values differ. Don't care if

    these were NULLs and not .... We compensate for that in

    update_key_parts.

  */

  return diffs[0];

}





	/* Check if index is ok */



static int chk_index(MI_CHECK *param, MI_INFO *info, MI_KEYDEF *keyinfo,
@@ -641,8 +727,20 @@ static int chk_index(MI_CHECK *param, MI_INFO *info, MI_KEYDEF *keyinfo, 
          ha_key_cmp(keyinfo->seg,info->lastkey,key,USE_WHOLE_KEY,

                     SEARCH_FIND | SEARCH_NULL_ARE_NOT_EQUAL,

                     &diff_pos);

        else if (param->stats_method == MI_STATS_METHOD_IGNORE_NULLS)

        {

          diff_pos= mi_collect_stats_nonulls_next(keyinfo->seg, 

                                                  param->notnull_count,

                                                  info->lastkey, key);

        }

	param->unique_count[diff_pos-1]++;

      }

      else

      {  

        if (param->stats_method == MI_STATS_METHOD_IGNORE_NULLS)

          mi_collect_stats_nonulls_first(keyinfo->seg, param->notnull_count,

                                         key);

      }

    }

    (*key_checksum)+= mi_byte_checksum((byte*) key,

				       key_length- info->s->rec_reflength);
@@ -2088,7 +2186,8 @@ int mi_repair_by_sort(MI_CHECK *param, register MI_INFO *info, 


    if (param->testflag & T_STATISTICS)

      update_key_parts(sort_param.keyinfo, rec_per_key_part, sort_param.unique,

		       (ulonglong) info->state->records);

                       param->stats_method == MI_STATS_METHOD_IGNORE_NULLS?

                       sort_param.notnull: NULL,(ulonglong) info->state->records);

    share->state.key_map|=(ulonglong) 1 << sort_param.key;



    if (sort_param.fix_datafile)
@@ -3255,11 +3354,21 @@ static int sort_key_write(MI_SORT_PARAM *sort_param, const void *a) 
      ha_key_cmp(sort_param->seg,sort_info->key_block->lastkey,

                 (uchar*) a, USE_WHOLE_KEY, 

                 SEARCH_FIND | SEARCH_NULL_ARE_NOT_EQUAL, &diff_pos);

    else if (param->stats_method == MI_STATS_METHOD_IGNORE_NULLS)

    {

      diff_pos= mi_collect_stats_nonulls_next(sort_param->seg,

                                              sort_param->notnull,

                                              sort_info->key_block->lastkey,

                                              (uchar*)a);

    }

    sort_param->unique[diff_pos-1]++;

  }

  else

  {

    cmp= -1;

    if (param->stats_method == MI_STATS_METHOD_IGNORE_NULLS)

      mi_collect_stats_nonulls_first(sort_param->seg, sort_param->notnull,

                                     (uchar*)a);

  }

  if ((sort_param->keyinfo->flag & HA_NOSAME) && cmp == 0)

  {
@@ -3981,21 +4090,30 @@ void update_auto_increment_key(MI_CHECK *param, MI_INFO *info, 
  

  SYNOPSIS

    update_key_parts()

      keyinfo               Index information (only key->keysegs used)

      keyinfo           IN  Index information (only key->keysegs used)

      rec_per_key_part  OUT Store statistics here

      unique            IN  Array of #distinct values collected over index

                            run.

      unique            IN  Array of (#distinct tuples)

      notnull_tuples    IN  Array of (#tuples), or NULL

      records               Number of records in the table

      

  NOTES

    This function handles all 3 index statistics collection methods.



    Unique is an array:

    unique[0]= (#different values of {keypart1}) - 1

    unique[1]= (#different values of {keypart2,keypart1} tuple) - unique[0] - 1

    unique[1]= (#different values of {keypart1,keypart2} tuple) - unique[0] - 1

    ...

    

    For MI_STATS_METHOD_IGNORE_NULLS notnull_tuples is an array too:

    notnull_tuples[0]= (# of {keypart1} tuples such that keypart1 is not NULL)

    notnull_tuples[1]= (# of {keypart1,keypart2} tuples such that all 

                        keypart{i} are not NULL)

    ...

    For all other statistics collection methods notnull_tuples=NULL.

      

    The 'unique' array is collected in one sequential scan through the entire

    index. This is done in two places: in chk_index() and in sort_key_write().

    Statistics collection may consider NULLs as either equal or unequal (see

    SEARCH_NULL_ARE_NOT_EQUAL, MI_STATS_METHOD_*).

    notnull_tuples, if present, is collected during the same index scan.



    Output is an array:

    rec_per_key_part[k] =
@@ -4007,25 +4125,53 @@ void update_auto_increment_key(MI_CHECK *param, MI_INFO *info, 
        index tuples}

     

     = #tuples-in-the-index / #distinct-tuples-in-the-index.

    

    The #tuples-in-the-index and #distinct-tuples-in-the-index have different 

    meaning depending on which statistics collection method is used:

    

    MI_STATS_METHOD_*  how are nulls compared?  which tuples are counted?

     NULLS_EQUAL            NULL == NULL           all tuples in table

     NULLS_NOT_EQUAL        NULL != NULL           all tuples in table

     IGNORE_NULLS               n/a             tuples that don't have NULLs

*/



void update_key_parts(MI_KEYDEF *keyinfo, ulong *rec_per_key_part,

			     ulonglong *unique, ulonglong records)

                      ulonglong *unique, ulonglong *notnull,

                      ulonglong records)

{

  ulonglong count=0,tmp;

  ulonglong count=0,tmp, unique_tuples;

  ulonglong tuples= records;

  uint parts;

  for (parts=0 ; parts < keyinfo->keysegs  ; parts++)

  {

    count+=unique[parts];

    if (count == 0)

      tmp=records;

    unique_tuples= count + 1;    

    if (notnull)

    {

      tuples= notnull[parts];

      /* 

        #(unique_tuples not counting tuples with NULLs) = 

          #(unique_tuples counting tuples with NULLs as different) - 

          #(tuples with NULLs)

      */

      unique_tuples -= (records - notnull[parts]);

    }

    

    if (unique_tuples == 0)

      tmp= 1;

    else if (count == 0)

      tmp= tuples; /* 1 unique tuple */

    else

      tmp= (records + (count+1)/2) / (count+1);

    /* for some weird keys (e.g. FULLTEXT) tmp can be <1 here.

       let's ensure it is not */

      tmp= (tuples + unique_tuples/2) / unique_tuples;



    /* 

      for some weird keys (e.g. FULLTEXT) tmp can be <1 here. 

      let's ensure it is not

    */

    set_if_bigger(tmp,1);

    if (tmp >= (ulonglong) ~(ulong) 0)

      tmp=(ulonglong) ~(ulong) 0;



    *rec_per_key_part=(ulong) tmp;

    rec_per_key_part++;

  }

myisam/myisamchk.c

+20 −4
Original line number Diff line number Diff line
@@ -339,7 +339,8 @@ static struct my_option my_long_options[] = 
    REQUIRED_ARG, 0, 0, 0, 0, 0, 0},

  {"stats_method", OPT_STATS_METHOD,

   "Specifies how index statistics collection code should threat NULLs. "

   "Possible values of name are \"nulls_unequal\" (default behavior for 4.1/5.0), and \"nulls_equal\" (emulate 4.0 behavior).",

   "Possible values of name are \"nulls_unequal\" (default behavior for 4.1/5.0), "

   "\"nulls_equal\" (emulate 4.0 behavior), and \"nulls_ignored\".",

   (gptr*) &myisam_stats_method_str, (gptr*) &myisam_stats_method_str, 0,

    GET_STR, REQUIRED_ARG, 0, 0, 0, 0, 0, 0},

  { 0, 0, 0, 0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0}
@@ -451,6 +452,10 @@ static void usage(void) 
  -a, --analyze	      Analyze distribution of keys. Will make some joins in\n\

		      MySQL faster.  You can check the calculated distribution\n\

		      by using '--description --verbose table_name'.\n\

  --stats_method=name Specifies how index statistics collection code should\n\

                      threat NULLs. Possible values of name are \"nulls_unequal\"\n\

                      (default for 4.1/5.0), \"nulls_equal\" (emulate 4.0), and \n\

                      \"nulls_ignored\".\n\

  -d, --description   Prints some information about table.\n\

  -A, --set-auto-increment[=value]\n\

		      Force auto_increment to start at this or higher value\n\
@@ -472,7 +477,7 @@ static void usage(void) 
#include <help_end.h>



const char *myisam_stats_method_names[] = {"nulls_unequal", "nulls_equal",

                                           NullS};

                                           "nulls_ignored", NullS};

TYPELIB myisam_stats_method_typelib= {

  array_elements(myisam_stats_method_names) - 1, "",

  myisam_stats_method_names, NULL};
@@ -699,14 +704,25 @@ get_one_option(int optid, 
  case OPT_STATS_METHOD:

  {

    int method;

    enum_mi_stats_method method_conv;

    myisam_stats_method_str= argument;

    if ((method=find_type(argument, &myisam_stats_method_typelib, 2)) <= 0)

    {

      fprintf(stderr, "Invalid value of stats_method: %s.\n", argument);

      exit(1);

    }

    check_param.stats_method= test(method-1)? MI_STATS_METHOD_NULLS_EQUAL :

                                              MI_STATS_METHOD_NULLS_NOT_EQUAL;

    switch (method-1) {

    case 0: 

      method_conv= MI_STATS_METHOD_NULLS_EQUAL;

      break;

    case 1:

      method_conv= MI_STATS_METHOD_NULLS_NOT_EQUAL;

      break;

    case 2:

      method_conv= MI_STATS_METHOD_IGNORE_NULLS;

      break;

    }

    check_param.stats_method= method_conv;

    break;

  }

#ifdef DEBUG					/* Only useful if debugging */