Details
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Bug
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Status: Closed (View Workflow)
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Blocker
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Resolution: Fixed
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10.4(EOL)
Description
create table t2 (kp1 int, kp2 int, key(kp1, kp2)); |
insert into t2 values (1,1),(1,5),(5,1),(5,5); |
set optimizer_trace=1; |
select * from t2 force index(kp1) where (kp1=2 and kp2 >=4); |
select * from information_schema.optimizer_trace;
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shows
"range_scan_alternatives": [
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{
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"index": "kp1",
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"ranges": ["(2,3) <= (kp1,kp2)"],
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"rowid_ordered": false,
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"using_mrr": false,
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"index_only": false,
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"rows": 10,
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"cost": 58.75,
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"chosen": true
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}
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],
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This is clearly incorrect as kp1=2 allows the range to have an upper bound too.
Attachments
Activity
The issue is that print_range() checks range->range_flag for flags like NO_MIN_RANGE or NO_MAX_RANGE.
sel_arg_range_seq_next() doesn't set that correctly (it sets it based only on the last key component).
The rest of the code only checks KEY_MULTI_RANGE::range_flag for flags describing both endpoints, like EQ_RANGE, NULL_RANGE, UNIQUE_RANGE.
As for whether the left/right endpoints are inclusive, this is obtained from start_key.flag and end_key.flag, respectively.
"infinite" endpoints have length=0.
(gdb) wher 5#0 print_range (out=0x7ffff4118630, key_part=0x7ffc9001fb60, range=0x7ffff41180c0, n_key_parts=2) at /home/psergey/dev-git2/10.5-cl/sql/opt_range.cc:15797#1 0x000055555630c85d in trace_ranges (range_trace=0x7ffff4118740, param=0x7ffff41189b0, idx=0, keypart=0x7ffc90089fe0, key_parts=0x7ffc9001fb60) at /home/psergey/dev-git2/10.5-cl/sql/opt_range.cc:15880#2 0x00005555562e9b53 in TRP_RANGE::trace_basic_info (this=0x7ffc9008a0e0, param=0x7ffff41189b0, trace_object=0x7ffff4118950) at /home/psergey/dev-git2/10.5-cl/sql/opt_range.cc:2272#3 0x00005555562ebf19 in SQL_SELECT::test_quick_select (this=0x7ffc900168f0, thd=0x7ffc90000d78, keys_to_use=..., prev_tables=0, limit=18446744073709551615, force_quick_range=false, ordered_output=false, remove_false_parts_of_where=true, only_single_index_range_scan=false) at /home/psergey/dev-git2/10.5-cl/sql/opt_range.cc:3036#4 0x0000555555e5c771 in get_quick_record_count (thd=0x7ffc90000d78, select=0x7ffc900168f0, table=0x7ffc90023648, keys=0x7ffc90015790, limit=18446744073709551615) at /home/psergey/dev-git2/10.5-cl/sql/sql_select.cc:4712in print_range:
(gdb) p *range$29 = {start_key = {key = 0x7ffc90089e48 "",length = 10,keypart_map = 3,flag = HA_READ_KEY_EXACT},end_key = {key = 0x7ffc90089e58 "",length = 5,keypart_map = 1,flag = HA_READ_AFTER_KEY},ptr = 0x1,range_flag = 2}That is, the range itself is correct.