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EXPLAIN FORMAT=JSON: Support range+MRR plans (when MRR is used but BKA is not)

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Sergei Petrunia
2014-12-06 01:11:22 +03:00
parent 8fb2c80fdb
commit 9cac7649ea
4 changed files with 53 additions and 0 deletions
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27
mysql-test/r/explain_json.result
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@ -665,4 +665,31 @@ EXPLAIN
}
set optimizer_switch=@tmp;
drop table t1,t2;
#
# MRR for range access (no BKA, just MRR)
#
create table t1 (a int, b int, key(a));
insert into t1 select tbl1.a+10*tbl2.a, 12345 from t0 tbl1, t0 tbl2;
set @tmp= @@optimizer_switch;
set optimizer_switch='mrr=on,mrr_sort_keys=on';
explain format=json select * from t1 where a < 3;
EXPLAIN
{
"query_block": {
"select_id": 1,
"table": {
"table_name": "t1",
"access_type": "range",
"possible_keys": ["a"],
"key": "a",
"key_length": "5",
"used_key_parts": ["a"],
"rows": 1,
"filtered": 100,
"index_condition": "(t1.a < 3)",
"mrr_type": "Rowid-ordered scan"
}
}
}
drop table t1;
drop table t0;