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Update cost for hash and cached joins
The old code did not't correctly add TIME_FOR_COMPARE to rows that are part of the scan that will be compared with the attached where clause. Now the cost calculation for hash join and full join cache join are identical except for HASH_FANOUT (10%) The cost for a join with keys is now also uniform. The total cost for a using a key for lookup is calculated in one place as: (cost_of_finding_rows_through_key(records) + records/TIME_FOR_COMPARE)* record_count_of_previous_row_combinations + startup_cost startup_cost is the cost of a creating a temporary table (if needed) Best_cost now includes the cost of comparing all WHERE clauses and also cost of joining with previous row combinations. Other things: - Optimizer trace is now printing the total costs, including testing the WHERE clause (TIME_FOR_COMPARE) and comparing with all previous rows. - In optimizer trace, include also total cost of query together with the final join order. This makes it easier to find out where the cost was calculated. - Old code used filter even if the cost for it was higher than not using a filter. This is not corrected. - When rebasing on 10.11, I noticed some changes to access_cost_factor calculation. These changes was not picked as the coming changes to filtering will make that code obsolete.
This commit is contained in:
Monty
Sergei Petrunia
@ -127,7 +127,7 @@ id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t7 eq_ref PRIMARY PRIMARY 4 test.t6.c62 1 Using index
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show status like 'Last_query_cost';
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Variable_name Value
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Last_query_cost 1693.637037
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Last_query_cost 3350.237037
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explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 ALL NULL NULL NULL NULL 3
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@ -139,7 +139,7 @@ id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t7 eq_ref PRIMARY PRIMARY 4 test.t6.c62 1 Using index
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show status like 'Last_query_cost';
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Variable_name Value
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Last_query_cost 1693.637037
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Last_query_cost 3350.237037
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explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t2 ALL NULL NULL NULL NULL 6
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@ -151,7 +151,7 @@ id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
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show status like 'Last_query_cost';
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Variable_name Value
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Last_query_cost 642.737037
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Last_query_cost 1276.787037
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explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t2 ALL NULL NULL NULL NULL 6
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@ -163,7 +163,7 @@ id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
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show status like 'Last_query_cost';
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Variable_name Value
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Last_query_cost 642.737037
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Last_query_cost 1276.787037
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explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t2 ALL NULL NULL NULL NULL 6
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@ -175,7 +175,7 @@ id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
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show status like 'Last_query_cost';
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Variable_name Value
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Last_query_cost 642.737037
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Last_query_cost 1276.787037
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explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t2 ALL NULL NULL NULL NULL 6
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@ -187,7 +187,7 @@ id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
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show status like 'Last_query_cost';
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Variable_name Value
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Last_query_cost 642.737037
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Last_query_cost 1276.787037
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set optimizer_prune_level=0;
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select @@optimizer_prune_level;
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@@optimizer_prune_level
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@ -207,7 +207,7 @@ id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 ALL NULL NULL NULL NULL 3 Using where; Using join buffer (flat, BNL join)
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show status like 'Last_query_cost';
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Variable_name Value
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Last_query_cost 1371.437037
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Last_query_cost 2705.237037
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explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t2 ALL NULL NULL NULL NULL 6 Using where
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@ -219,7 +219,7 @@ id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 ALL NULL NULL NULL NULL 3 Using where; Using join buffer (flat, BNL join)
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show status like 'Last_query_cost';
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Variable_name Value
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Last_query_cost 1371.437037
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Last_query_cost 2705.237037
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explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t2 ALL NULL NULL NULL NULL 6 Using where
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@ -231,7 +231,7 @@ id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
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show status like 'Last_query_cost';
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Variable_name Value
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Last_query_cost 362.618727
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Last_query_cost 701.018727
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explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t2 ALL NULL NULL NULL NULL 6 Using where
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@ -243,7 +243,7 @@ id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
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show status like 'Last_query_cost';
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Variable_name Value
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Last_query_cost 362.618727
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Last_query_cost 701.018727
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explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t2 ALL NULL NULL NULL NULL 6 Using where
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@ -255,7 +255,7 @@ id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
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show status like 'Last_query_cost';
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Variable_name Value
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Last_query_cost 362.618727
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Last_query_cost 701.018727
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explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t2 ALL NULL NULL NULL NULL 6 Using where
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@ -267,7 +267,7 @@ id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
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show status like 'Last_query_cost';
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Variable_name Value
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Last_query_cost 362.618727
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Last_query_cost 701.018727
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set optimizer_search_depth=1;
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select @@optimizer_search_depth;
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@@optimizer_search_depth
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@ -283,7 +283,7 @@ id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t7 eq_ref PRIMARY PRIMARY 4 test.t6.c62 1 Using index
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show status like 'Last_query_cost';
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Variable_name Value
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Last_query_cost 1693.637037
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Last_query_cost 3350.237037
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explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 ALL NULL NULL NULL NULL 3
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@ -295,7 +295,7 @@ id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t7 eq_ref PRIMARY PRIMARY 4 test.t6.c62 1 Using index
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show status like 'Last_query_cost';
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Variable_name Value
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Last_query_cost 1693.637037
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Last_query_cost 3350.237037
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explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 ALL PRIMARY NULL NULL NULL 3 Using where
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@ -307,7 +307,7 @@ id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
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show status like 'Last_query_cost';
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Variable_name Value
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Last_query_cost 844.037037
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Last_query_cost 1678.037037
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explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 ALL PRIMARY NULL NULL NULL 3 Using where
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@ -319,7 +319,7 @@ id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
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show status like 'Last_query_cost';
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Variable_name Value
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Last_query_cost 844.037037
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Last_query_cost 1678.037037
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explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 ALL PRIMARY NULL NULL NULL 3 Using where
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@ -331,7 +331,7 @@ id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
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show status like 'Last_query_cost';
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Variable_name Value
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Last_query_cost 844.037037
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Last_query_cost 1678.037037
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explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
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id select_type table type possible_keys key key_len ref rows Extra
|
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1 SIMPLE t1 ALL PRIMARY NULL NULL NULL 3 Using where
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@ -343,7 +343,7 @@ id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
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show status like 'Last_query_cost';
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Variable_name Value
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Last_query_cost 844.037037
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Last_query_cost 1678.037037
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set optimizer_search_depth=62;
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select @@optimizer_search_depth;
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@@optimizer_search_depth
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@ -359,7 +359,7 @@ id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 ALL NULL NULL NULL NULL 3 Using where; Using join buffer (flat, BNL join)
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show status like 'Last_query_cost';
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Variable_name Value
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Last_query_cost 1371.437037
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Last_query_cost 2705.237037
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explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
|
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id select_type table type possible_keys key key_len ref rows Extra
|
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1 SIMPLE t2 ALL NULL NULL NULL NULL 6 Using where
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@ -371,7 +371,7 @@ id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 ALL NULL NULL NULL NULL 3 Using where; Using join buffer (flat, BNL join)
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show status like 'Last_query_cost';
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Variable_name Value
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Last_query_cost 1371.437037
|
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Last_query_cost 2705.237037
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explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
|
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id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t2 ALL NULL NULL NULL NULL 6 Using where
|
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@ -383,7 +383,7 @@ id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
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show status like 'Last_query_cost';
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Variable_name Value
|
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Last_query_cost 362.618727
|
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Last_query_cost 701.018727
|
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explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t2 ALL NULL NULL NULL NULL 6 Using where
|
||||
@ -395,7 +395,7 @@ id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
|
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show status like 'Last_query_cost';
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Variable_name Value
|
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Last_query_cost 362.618727
|
||||
Last_query_cost 701.018727
|
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explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t2 ALL NULL NULL NULL NULL 6 Using where
|
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@ -407,7 +407,7 @@ id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
|
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show status like 'Last_query_cost';
|
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Variable_name Value
|
||||
Last_query_cost 362.618727
|
||||
Last_query_cost 701.018727
|
||||
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t2 ALL NULL NULL NULL NULL 6 Using where
|
||||
@ -419,7 +419,7 @@ id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
|
||||
show status like 'Last_query_cost';
|
||||
Variable_name Value
|
||||
Last_query_cost 362.618727
|
||||
Last_query_cost 701.018727
|
||||
set optimizer_prune_level=2;
|
||||
select @@optimizer_prune_level;
|
||||
@@optimizer_prune_level
|
||||
@ -439,7 +439,7 @@ id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t7 eq_ref PRIMARY PRIMARY 4 test.t6.c62 1 Using index
|
||||
show status like 'Last_query_cost';
|
||||
Variable_name Value
|
||||
Last_query_cost 1693.637037
|
||||
Last_query_cost 3350.237037
|
||||
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t1 ALL NULL NULL NULL NULL 3
|
||||
@ -451,7 +451,7 @@ id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t7 eq_ref PRIMARY PRIMARY 4 test.t6.c62 1 Using index
|
||||
show status like 'Last_query_cost';
|
||||
Variable_name Value
|
||||
Last_query_cost 1693.637037
|
||||
Last_query_cost 3350.237037
|
||||
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t2 ALL NULL NULL NULL NULL 6
|
||||
@ -463,7 +463,7 @@ id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
|
||||
show status like 'Last_query_cost';
|
||||
Variable_name Value
|
||||
Last_query_cost 642.737037
|
||||
Last_query_cost 1276.787037
|
||||
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t2 ALL NULL NULL NULL NULL 6
|
||||
@ -475,7 +475,7 @@ id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
|
||||
show status like 'Last_query_cost';
|
||||
Variable_name Value
|
||||
Last_query_cost 642.737037
|
||||
Last_query_cost 1276.787037
|
||||
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t2 ALL NULL NULL NULL NULL 6
|
||||
@ -487,7 +487,7 @@ id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
|
||||
show status like 'Last_query_cost';
|
||||
Variable_name Value
|
||||
Last_query_cost 642.737037
|
||||
Last_query_cost 1276.787037
|
||||
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t2 ALL NULL NULL NULL NULL 6
|
||||
@ -499,7 +499,7 @@ id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
|
||||
show status like 'Last_query_cost';
|
||||
Variable_name Value
|
||||
Last_query_cost 642.737037
|
||||
Last_query_cost 1276.787037
|
||||
set optimizer_search_depth=1;
|
||||
select @@optimizer_search_depth;
|
||||
@@optimizer_search_depth
|
||||
@ -515,7 +515,7 @@ id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t7 eq_ref PRIMARY PRIMARY 4 test.t6.c62 1 Using index
|
||||
show status like 'Last_query_cost';
|
||||
Variable_name Value
|
||||
Last_query_cost 1693.637037
|
||||
Last_query_cost 3350.237037
|
||||
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t1 ALL NULL NULL NULL NULL 3
|
||||
@ -527,7 +527,7 @@ id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t7 eq_ref PRIMARY PRIMARY 4 test.t6.c62 1 Using index
|
||||
show status like 'Last_query_cost';
|
||||
Variable_name Value
|
||||
Last_query_cost 1693.637037
|
||||
Last_query_cost 3350.237037
|
||||
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t1 ALL PRIMARY NULL NULL NULL 3 Using where
|
||||
@ -539,7 +539,7 @@ id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
|
||||
show status like 'Last_query_cost';
|
||||
Variable_name Value
|
||||
Last_query_cost 844.037037
|
||||
Last_query_cost 1678.037037
|
||||
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t1 ALL PRIMARY NULL NULL NULL 3 Using where
|
||||
@ -551,7 +551,7 @@ id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
|
||||
show status like 'Last_query_cost';
|
||||
Variable_name Value
|
||||
Last_query_cost 844.037037
|
||||
Last_query_cost 1678.037037
|
||||
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t1 ALL PRIMARY NULL NULL NULL 3 Using where
|
||||
@ -563,7 +563,7 @@ id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
|
||||
show status like 'Last_query_cost';
|
||||
Variable_name Value
|
||||
Last_query_cost 844.037037
|
||||
Last_query_cost 1678.037037
|
||||
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t1 ALL PRIMARY NULL NULL NULL 3 Using where
|
||||
@ -575,7 +575,7 @@ id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
|
||||
show status like 'Last_query_cost';
|
||||
Variable_name Value
|
||||
Last_query_cost 844.037037
|
||||
Last_query_cost 1678.037037
|
||||
set optimizer_search_depth=62;
|
||||
select @@optimizer_search_depth;
|
||||
@@optimizer_search_depth
|
||||
@ -591,7 +591,7 @@ id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t7 eq_ref PRIMARY PRIMARY 4 test.t6.c62 1 Using index
|
||||
show status like 'Last_query_cost';
|
||||
Variable_name Value
|
||||
Last_query_cost 1693.637037
|
||||
Last_query_cost 3350.237037
|
||||
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t1 ALL NULL NULL NULL NULL 3
|
||||
@ -603,7 +603,7 @@ id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t7 eq_ref PRIMARY PRIMARY 4 test.t6.c62 1 Using index
|
||||
show status like 'Last_query_cost';
|
||||
Variable_name Value
|
||||
Last_query_cost 1693.637037
|
||||
Last_query_cost 3350.237037
|
||||
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t2 ALL NULL NULL NULL NULL 6
|
||||
@ -615,7 +615,7 @@ id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
|
||||
show status like 'Last_query_cost';
|
||||
Variable_name Value
|
||||
Last_query_cost 642.737037
|
||||
Last_query_cost 1276.787037
|
||||
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t2 ALL NULL NULL NULL NULL 6
|
||||
@ -627,7 +627,7 @@ id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
|
||||
show status like 'Last_query_cost';
|
||||
Variable_name Value
|
||||
Last_query_cost 642.737037
|
||||
Last_query_cost 1276.787037
|
||||
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t2 ALL NULL NULL NULL NULL 6
|
||||
@ -639,7 +639,7 @@ id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
|
||||
show status like 'Last_query_cost';
|
||||
Variable_name Value
|
||||
Last_query_cost 642.737037
|
||||
Last_query_cost 1276.787037
|
||||
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t2 ALL NULL NULL NULL NULL 6
|
||||
@ -651,7 +651,7 @@ id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t6 ALL NULL NULL NULL NULL 18 Using where; Using join buffer (flat, BNL join)
|
||||
show status like 'Last_query_cost';
|
||||
Variable_name Value
|
||||
Last_query_cost 642.737037
|
||||
Last_query_cost 1276.787037
|
||||
drop table t1,t2,t3,t4,t5,t6,t7;
|
||||
CREATE TABLE t1 (a int, b int, d int, i int);
|
||||
INSERT INTO t1 VALUES (1,1,1,1);
|
||||
|
||||
Reference in New Issue
Block a user