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Complete implementation of WL#1469 "Greedy algorithm to search for an optimal execution plan",

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consisting of pos-review fixes and improvements.


mysql-test/r/distinct.result:
  Adjusted to account for pre-sorting of tables before optimiziation.
mysql-test/r/func_group.result:
  Adjusted to account for pre-sorting of tables before optimiziation.
mysql-test/r/greedy_optimizer.result:
  - Adjusted to account for pre-sorting of tables before optimiziation.
  - Removed unnecessary test.
  - More comments.
mysql-test/r/select.result:
  - Adjusted to account for pre-sorting of tables before optimiziation.
mysql-test/t/greedy_optimizer.test:
  - Adjusted to account for pre-sorting of tables before optimiziation.
  - Removed unnecessary test.
  - More comments.
sql/mysql_priv.h:
  Moved function print_plan() to sql_test.cc
sql/sql_select.cc:
  - Simplified the recursion in best_extension_by_limited_search()
    and aligned it with its pseudo-code.
  - Renamed functions to better reflect their semantics.
  - Post-review changes of function specifications.
  - Moved function print_plan() to sql_test.cc.
sql/sql_test.cc:
  Moved function print_plan() to sql_test.cc
This commit is contained in:
unknown
2004-05-10 15:48:50 +03:00
parent 4c56ede41c
commit a51ba6133d
8 changed files with 627 additions and 538 deletions
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96
sql/sql_test.cc
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@ -232,6 +232,102 @@ TEST_join(JOIN *join)
DBUG_VOID_RETURN;
}
/*
Print the current state during query optimization.
SYNOPSIS
print_plan()
join pointer to the structure providing all context info for
the query
read_time the cost of the best partial plan
record_count estimate for the number of records returned by the best
partial plan
idx length of the partial QEP in 'join->positions';
also an index in the array 'join->best_ref';
info comment string to appear above the printout
DESCRIPTION
This function prints to the log file DBUG_FILE the members of 'join' that
are used during query optimization (join->positions, join->best_positions,
and join->best_ref) and few other related variables (read_time,
record_count).
Useful to trace query optimizer functions.
RETURN
None
*/
void
print_plan(JOIN* join, double read_time, double record_count,
uint idx, const char *info)
{
uint i;
POSITION pos;
JOIN_TAB *join_table;
JOIN_TAB **plan_nodes;
TABLE* table;
if (info == 0)
info= "";
DBUG_LOCK_FILE;
if (join->best_read == DBL_MAX)
{
fprintf(DBUG_FILE,"%s; idx:%u, best: DBL_MAX, current:%g\n",
info, idx, read_time);
}
else
{
fprintf(DBUG_FILE,"%s; idx: %u, best: %g, current: %g\n",
info, idx, join->best_read, read_time);
}
/* Print the tables in JOIN->positions */
fputs(" POSITIONS: ", DBUG_FILE);
for (i= 0; i < idx ; i++)
{
pos = join->positions[i];
table= pos.table->table;
if (table)
fputs(table->real_name, DBUG_FILE);
fputc(' ', DBUG_FILE);
}
fputc('\n', DBUG_FILE);
/*
Print the tables in JOIN->best_positions only if at least one complete plan
has been found. An indicator for this is the value of 'join->best_read'.
*/
fputs("BEST_POSITIONS: ", DBUG_FILE);
if (join->best_read < DBL_MAX)
{
for (i= 0; i < idx ; i++)
{
pos= join->best_positions[i];
table= pos.table->table;
if (table)
fputs(table->real_name, DBUG_FILE);
fputc(' ', DBUG_FILE);
}
}
fputc('\n', DBUG_FILE);
/* Print the tables in JOIN->best_ref */
fputs(" BEST_REF: ", DBUG_FILE);
for (plan_nodes= join->best_ref ; *plan_nodes ; plan_nodes++)
{
join_table= (*plan_nodes);
fputs(join_table->table->real_name, DBUG_FILE);
fprintf(DBUG_FILE, "(%u,%u,%u)",
join_table->found_records, join_table->records, join_table->read_time);
fputc(' ', DBUG_FILE);
}
fputc('\n', DBUG_FILE);
DBUG_UNLOCK_FILE;
}
#endif
typedef struct st_debug_lock