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|
SET optimizer_trace_max_mem_size=1048576;
SET @@session.optimizer_trace="enabled=on";
#
# BUG#18195373: OPTIMIZER TRACE SHOULD PRINT NAME OF
# INDEX FOR RANGE ACCESS
CREATE TABLE t1 (a VARCHAR(200), b TEXT, FULLTEXT (a,b));
INSERT INTO t1 VALUES('Testing how', 'full-text search'),
('is printed to the', 'optimizer trace.'),
('We need test coverage','of that too');
SELECT * FROM t1 WHERE MATCH(a,b) AGAINST ("coverage");
a b
We need test coverage of that too
SELECT * FROM information_schema.OPTIMIZER_TRACE;
QUERY TRACE MISSING_BYTES_BEYOND_MAX_MEM_SIZE INSUFFICIENT_PRIVILEGES
SELECT * FROM t1 WHERE MATCH(a,b) AGAINST ("coverage") {
"steps": [
{
"join_preparation": {
"select#": 1,
"steps": [
{
"expanded_query": "/* select#1 */ select `t1`.`a` AS `a`,`t1`.`b` AS `b` from `t1` where (match `t1`.`a`,`t1`.`b` against ('coverage'))"
}
]
}
},
{
"join_optimization": {
"select#": 1,
"steps": [
{
"condition_processing": {
"condition": "WHERE",
"original_condition": "(match `t1`.`a`,`t1`.`b` against ('coverage'))",
"steps": [
{
"transformation": "equality_propagation",
"resulting_condition": "(match `t1`.`a`,`t1`.`b` against ('coverage'))"
},
{
"transformation": "constant_propagation",
"resulting_condition": "(match `t1`.`a`,`t1`.`b` against ('coverage'))"
},
{
"transformation": "trivial_condition_removal",
"resulting_condition": "(match `t1`.`a`,`t1`.`b` against ('coverage'))"
}
]
}
},
{
"substitute_generated_columns": {
}
},
{
"table_dependencies": [
{
"table": "`t1`",
"row_may_be_null": false,
"map_bit": 0,
"depends_on_map_bits": [
]
}
]
},
{
"ref_optimizer_key_uses": [
{
"table": "`t1`",
"field": "<fulltext>",
"equals": "(match `t1`.`a`,`t1`.`b` against ('coverage'))",
"null_rejecting": false
}
]
},
{
"rows_estimation": [
{
"table": "`t1`",
"range_analysis": {
"table_scan": {
"rows": 3,
"cost": 2.90732
},
"potential_range_indexes": [
{
"index": "a",
"usable": false,
"cause": "fulltext"
}
],
"setup_range_conditions": [
],
"group_index_range": {
"chosen": false,
"cause": "not_group_by_or_distinct"
},
"skip_scan_range": {
"chosen": false,
"cause": "disjuntive_predicate_present"
}
}
}
]
},
{
"considered_execution_plans": [
{
"plan_prefix": [
],
"table": "`t1`",
"best_access_path": {
"considered_access_paths": [
{
"access_type": "fulltext",
"index": "a",
"rows": 1,
"cost": 0.35,
"chosen": true
},
{
"access_type": "scan",
"cost": 0.807324,
"rows": 3,
"chosen": false,
"cause": "cost"
}
]
},
"condition_filtering_pct": 100,
"rows_for_plan": 1,
"cost_for_plan": 0.35,
"chosen": true
}
]
},
{
"attaching_conditions_to_tables": {
"original_condition": "(match `t1`.`a`,`t1`.`b` against ('coverage'))",
"attached_conditions_computation": [
],
"attached_conditions_summary": [
{
"table": "`t1`",
"attached": "(match `t1`.`a`,`t1`.`b` against ('coverage'))"
}
]
}
},
{
"finalizing_table_conditions": [
{
"table": "`t1`",
"original_table_condition": "(match `t1`.`a`,`t1`.`b` against ('coverage'))",
"final_table_condition ": "(match `t1`.`a`,`t1`.`b` against ('coverage'))"
}
]
},
{
"refine_plan": [
{
"table": "`t1`"
}
]
}
]
}
},
{
"join_execution": {
"select#": 1,
"steps": [
]
}
}
]
} 0 0
DROP TABLE t1;
|
