mirror of
https://github.com/MariaDB/server.git
synced 2025-01-27 01:04:19 +01:00
cdc7253787
MyISAM and Aria used to lie to the server about the reflength value. One value was used internally, it was stored on disk, e.g. in indexes, and couldn't be changed without full table rebuild. A differently calculated value was reported to the server - that value was sometimes larger than the true reflength. That caused the server to allocate more memory per position than necessary - affecting filesort, join buffer usage, optimizer cost calculations, and may be more.
2007 lines
47 KiB
Text
2007 lines
47 KiB
Text
drop table if exists t0,t1,t2,t3;
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create table t0(a int);
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insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
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create table t1(a int);
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insert into t1 select A.a + B.a* 10 from t0 A, t0 B;
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create table t2 (pk int primary key, a datetime, b date, key(a), key(b));
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insert into t2
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select
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A.a*10+B.a,
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date_add(date_add('2017-01-01', interval A.a*8 day), interval B.a hour),
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date_add('2017-01-01', interval A.a*7 day)
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from t1 A, t0 B;
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analyze table t2;
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Table Op Msg_type Msg_text
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test.t2 analyze status Engine-independent statistics collected
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test.t2 analyze status Table is already up to date
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#
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# "YEAR(datetime_col) CMP year_value", basic checks
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#
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select count(*) from t2 where year(a) < 2018;
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count(*)
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460
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# Compare the results, they must be equal:
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select count(*) from t2 where a < '2018-01-01';
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count(*)
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460
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explain format=json select count(*) from t2 where year(a) < 2018;
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EXPLAIN
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{
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"query_block": {
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"select_id": 1,
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"cost": 0.063940854,
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"nested_loop": [
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{
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"table": {
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"table_name": "t2",
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"access_type": "range",
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"possible_keys": ["a"],
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"key": "a",
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"key_length": "6",
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"used_key_parts": ["a"],
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"loops": 1,
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"rows": 451,
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"cost": 0.063940854,
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"filtered": 100,
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"attached_condition": "t2.a < '2018-01-01 00:00:00'",
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"using_index": true
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}
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}
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]
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}
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}
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# Check rewrite for a prepared statement:
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execute immediate
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"explain format=json select * from t2 where year(a) < ?"
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using 2018;
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EXPLAIN
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{
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"query_block": {
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"select_id": 1,
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"cost": 0.1671618,
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"nested_loop": [
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{
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"table": {
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"table_name": "t2",
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"access_type": "ALL",
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"possible_keys": ["a"],
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"loops": 1,
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"rows": 1000,
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"cost": 0.1671618,
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"filtered": 45.09999847,
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"attached_condition": "t2.a < '2018-01-01 00:00:00'"
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}
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}
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]
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}
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}
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prepare stmt from "select count(*) from t2 where year(a) < 2018";
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execute stmt;
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count(*)
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460
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execute stmt;
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count(*)
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460
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create or replace view v1 as select count(*) from t2 where year(a) < 2018;
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select * from v1;
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count(*)
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460
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create or replace procedure sp() select count(*) from t2 where year(a) < 2018;
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call sp();
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count(*)
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460
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call sp();
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count(*)
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460
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# Prepared statement with a placeholder
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prepare stmt from "select count(*) from t2 where year(a) < ?";
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execute stmt using 2018;
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count(*)
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460
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execute stmt using 2017;
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count(*)
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0
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select count(*) from t2 where year(a) <= 2018;
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count(*)
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920
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select count(*) from t2 where a < '2019-01-01';
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count(*)
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920
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explain format=json select count(*) from t2 where year(a) <= 2018;
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EXPLAIN
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{
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"query_block": {
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"select_id": 1,
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"cost": 0.126438894,
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"nested_loop": [
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{
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"table": {
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"table_name": "t2",
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"access_type": "range",
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"possible_keys": ["a"],
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"key": "a",
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"key_length": "6",
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"used_key_parts": ["a"],
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"loops": 1,
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"rows": 903,
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"cost": 0.126438894,
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"filtered": 100,
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"attached_condition": "t2.a <= '2018-12-31 23:59:59'",
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"using_index": true
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}
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}
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]
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}
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}
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select count(*) from t2 where year(a) > 2018;
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count(*)
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80
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select count(*) from t2 where a > '2018-12-31 23:59:59.999999';
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count(*)
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80
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explain format=json select count(*) from t2 where year(a) > 2018;
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EXPLAIN
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{
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"query_block": {
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"select_id": 1,
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"cost": 0.014752874,
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"nested_loop": [
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{
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"table": {
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"table_name": "t2",
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"access_type": "range",
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"possible_keys": ["a"],
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"key": "a",
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"key_length": "6",
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"used_key_parts": ["a"],
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"loops": 1,
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"rows": 97,
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"cost": 0.014752874,
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"filtered": 100,
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"attached_condition": "t2.a > '2018-12-31 23:59:59'",
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"using_index": true
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}
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}
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]
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}
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}
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select count(*) from t2 where year(a) >= 2018;
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count(*)
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540
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select count(*) from t2 where a >= '2018-01-01';
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count(*)
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540
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explain format=json select count(*) from t2 where year(a) >= 2018;
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EXPLAIN
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{
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"query_block": {
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"select_id": 1,
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"cost": 0.077250914,
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"nested_loop": [
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{
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"table": {
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"table_name": "t2",
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"access_type": "range",
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"possible_keys": ["a"],
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"key": "a",
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"key_length": "6",
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"used_key_parts": ["a"],
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"loops": 1,
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"rows": 549,
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"cost": 0.077250914,
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"filtered": 100,
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"attached_condition": "t2.a >= '2018-01-01 00:00:00'",
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"using_index": true
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}
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}
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]
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}
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}
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select count(*) from t2 where year(a) = 2017;
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count(*)
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460
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select count(*) from t2 where a >= '2017-01-01' and a < '2018-01-01';
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count(*)
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460
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explain format=json select count(*) from t2 where year(a) = 2017;
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EXPLAIN
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{
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"query_block": {
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"select_id": 1,
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"cost": 0.063940854,
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"nested_loop": [
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{
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"table": {
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"table_name": "t2",
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"access_type": "range",
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"possible_keys": ["a"],
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"key": "a",
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"key_length": "6",
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"used_key_parts": ["a"],
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"loops": 1,
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"rows": 451,
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"cost": 0.063940854,
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"filtered": 100,
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"attached_condition": "t2.a between '2017-01-01 00:00:00' and '2017-12-31 23:59:59'",
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"using_index": true
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}
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}
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]
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}
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}
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#
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# "YEAR(datetime_col) CMP year_value", reverse argument order
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#
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select count(*) from t2 where 2017 < year(a);
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count(*)
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540
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select count(*) from t2 where a >= '2018-01-01';
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count(*)
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540
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explain format=json select count(*) from t2 where 2017 < year(a);
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EXPLAIN
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{
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"query_block": {
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"select_id": 1,
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"cost": 0.077250914,
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"nested_loop": [
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{
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"table": {
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"table_name": "t2",
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"access_type": "range",
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"possible_keys": ["a"],
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"key": "a",
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"key_length": "6",
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"used_key_parts": ["a"],
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"loops": 1,
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"rows": 549,
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"cost": 0.077250914,
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"filtered": 100,
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"attached_condition": "t2.a > '2017-12-31 23:59:59'",
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"using_index": true
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}
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}
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]
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}
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}
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select count(*) from t2 where a >= '2018-01-01';
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count(*)
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540
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explain format=json select count(*) from t2 where 2018 <= year(a);
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EXPLAIN
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{
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"query_block": {
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"select_id": 1,
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"cost": 0.077250914,
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"nested_loop": [
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{
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"table": {
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"table_name": "t2",
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"access_type": "range",
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"possible_keys": ["a"],
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"key": "a",
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"key_length": "6",
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"used_key_parts": ["a"],
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"loops": 1,
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"rows": 549,
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"cost": 0.077250914,
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"filtered": 100,
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"attached_condition": "t2.a >= '2018-01-01 00:00:00'",
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"using_index": true
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}
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}
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]
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}
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}
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select count(*) from t2 where 2018 > year(a);
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count(*)
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460
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select count(*) from t2 where a < '2018-01-01';
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count(*)
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460
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explain format=json select count(*) from t2 where 2018 > year(a);
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EXPLAIN
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{
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"query_block": {
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"select_id": 1,
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"cost": 0.063940854,
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"nested_loop": [
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{
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"table": {
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"table_name": "t2",
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"access_type": "range",
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"possible_keys": ["a"],
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"key": "a",
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"key_length": "6",
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"used_key_parts": ["a"],
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"loops": 1,
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"rows": 451,
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"cost": 0.063940854,
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"filtered": 100,
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"attached_condition": "t2.a < '2018-01-01 00:00:00'",
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"using_index": true
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}
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}
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]
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}
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}
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select count(*) from t2 where a < '2019-01-01';
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count(*)
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920
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explain format=json select count(*) from t2 where 2018 >= year(a);
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EXPLAIN
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{
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"query_block": {
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"select_id": 1,
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"cost": 0.126438894,
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"nested_loop": [
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{
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"table": {
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"table_name": "t2",
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"access_type": "range",
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"possible_keys": ["a"],
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"key": "a",
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"key_length": "6",
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"used_key_parts": ["a"],
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"loops": 1,
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"rows": 903,
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"cost": 0.126438894,
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"filtered": 100,
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"attached_condition": "t2.a <= '2018-12-31 23:59:59'",
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"using_index": true
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}
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}
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]
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}
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}
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select count(*) from t2 where 2018 = year(a);
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count(*)
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460
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select count(*) from t2 where a >= '2018-01-01' and a < '2019-01-01';
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count(*)
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460
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explain format=json select count(*) from t2 where 2018 = year(a);
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EXPLAIN
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{
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"query_block": {
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"select_id": 1,
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"cost": 0.064079124,
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"nested_loop": [
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{
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"table": {
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"table_name": "t2",
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"access_type": "range",
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"possible_keys": ["a"],
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"key": "a",
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"key_length": "6",
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"used_key_parts": ["a"],
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"loops": 1,
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"rows": 452,
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"cost": 0.064079124,
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"filtered": 100,
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"attached_condition": "t2.a between '2018-01-01 00:00:00' and '2018-12-31 23:59:59'",
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"using_index": true
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}
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}
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]
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}
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}
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#
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# "DATE(datetime_col) CMP date_value", basic checks
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#
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select count(*) from t2 where date(a) < '2017-06-01';
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count(*)
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190
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select count(*) from t2 where a < '2017-06-01';
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count(*)
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190
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explain format=json select count(*) from t2 where date(a) < '2017-06-01';
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EXPLAIN
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{
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"query_block": {
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"select_id": 1,
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"cost": 0.027058904,
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"nested_loop": [
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{
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"table": {
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"table_name": "t2",
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"access_type": "range",
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"possible_keys": ["a"],
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"key": "a",
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"key_length": "6",
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"used_key_parts": ["a"],
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"loops": 1,
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"rows": 186,
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"cost": 0.027058904,
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"filtered": 100,
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"attached_condition": "t2.a < '2017-06-01 00:00:00'",
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"using_index": true
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}
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}
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]
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}
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}
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select count(*) from t2 where date(a) <= '2017-06-03';
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count(*)
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200
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select count(*) from t2 where a < '2017-06-04';
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count(*)
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200
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explain format=json select count(*) from t2 where date(a) <= '2017-06-03';
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EXPLAIN
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{
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"query_block": {
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"select_id": 1,
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"cost": 0.028441604,
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"nested_loop": [
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{
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"table": {
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"table_name": "t2",
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"access_type": "range",
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"possible_keys": ["a"],
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"key": "a",
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"key_length": "6",
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"used_key_parts": ["a"],
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"loops": 1,
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"rows": 196,
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"cost": 0.028441604,
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"filtered": 100,
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"attached_condition": "t2.a <= '2017-06-03 23:59:59'",
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"using_index": true
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}
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}
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]
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}
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}
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select count(*) from t2 where date(a) > '2018-06-01';
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count(*)
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350
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select count(*) from t2 where a >= '2018-06-02';
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count(*)
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350
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explain format=json select count(*) from t2 where date(a) > '2018-06-01';
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EXPLAIN
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{
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"query_block": {
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"select_id": 1,
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"cost": 0.051773094,
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"nested_loop": [
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|
{
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"table": {
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"table_name": "t2",
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"access_type": "range",
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"possible_keys": ["a"],
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"key": "a",
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"key_length": "6",
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"used_key_parts": ["a"],
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"loops": 1,
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"rows": 363,
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"cost": 0.051773094,
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"filtered": 100,
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"attached_condition": "t2.a > '2018-06-01 23:59:59'",
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"using_index": true
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}
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}
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]
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}
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}
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select count(*) from t2 where date(a) >= '2018-06-01';
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count(*)
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350
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select count(*) from t2 where a >= '2018-06-01';
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count(*)
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350
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explain format=json select count(*) from t2 where date(a) >= '2018-06-01';
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EXPLAIN
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{
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"query_block": {
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"select_id": 1,
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"cost": 0.051773094,
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"nested_loop": [
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{
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|
"table": {
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"table_name": "t2",
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"access_type": "range",
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"possible_keys": ["a"],
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"key": "a",
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"key_length": "6",
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"used_key_parts": ["a"],
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"loops": 1,
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"rows": 363,
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|
"cost": 0.051773094,
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"filtered": 100,
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"attached_condition": "t2.a >= '2018-06-01 00:00:00'",
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"using_index": true
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}
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}
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]
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}
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}
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select count(*) from t2 where date(a) = '2017-06-02';
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count(*)
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10
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select count(*) from t2 where a >= '2017-06-02' and a < '2017-06-03';
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count(*)
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10
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explain format=json select count(*) from t2 where date(a) = '2017-06-02';
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EXPLAIN
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{
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"query_block": {
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"select_id": 1,
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"cost": 0.002723384,
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"nested_loop": [
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{
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"table": {
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"table_name": "t2",
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"access_type": "range",
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"possible_keys": ["a"],
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"key": "a",
|
|
"key_length": "6",
|
|
"used_key_parts": ["a"],
|
|
"loops": 1,
|
|
"rows": 10,
|
|
"cost": 0.002723384,
|
|
"filtered": 100,
|
|
"attached_condition": "t2.a between '2017-06-02 00:00:00' and '2017-06-02 23:59:59'",
|
|
"using_index": true
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
#
|
|
# "DATE(datetime_col) CMP date_value", reverse order
|
|
#
|
|
select count(*) from t2 where '2017-06-01' > date(a);
|
|
count(*)
|
|
190
|
|
select count(*) from t2 where '2017-06-01' > a;
|
|
count(*)
|
|
190
|
|
explain format=json select count(*) from t2 where '2017-06-01' > date(a);
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.027058904,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t2",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "6",
|
|
"used_key_parts": ["a"],
|
|
"loops": 1,
|
|
"rows": 186,
|
|
"cost": 0.027058904,
|
|
"filtered": 100,
|
|
"attached_condition": "t2.a < '2017-06-01 00:00:00'",
|
|
"using_index": true
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
select count(*) from t2 where '2017-06-03' >= date(a);
|
|
count(*)
|
|
200
|
|
select count(*) from t2 where '2017-06-03' >= a;
|
|
count(*)
|
|
200
|
|
explain format=json select count(*) from t2 where '2017-06-03' >= date(a);
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.028441604,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t2",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "6",
|
|
"used_key_parts": ["a"],
|
|
"loops": 1,
|
|
"rows": 196,
|
|
"cost": 0.028441604,
|
|
"filtered": 100,
|
|
"attached_condition": "t2.a <= '2017-06-03 23:59:59'",
|
|
"using_index": true
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
select count(*) from t2 where '2018-06-01' < date(a);
|
|
count(*)
|
|
350
|
|
select count(*) from t2 where '2018-06-02' <= a;
|
|
count(*)
|
|
350
|
|
explain format=json select count(*) from t2 where '2018-06-01' < date(a);
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.051773094,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t2",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "6",
|
|
"used_key_parts": ["a"],
|
|
"loops": 1,
|
|
"rows": 363,
|
|
"cost": 0.051773094,
|
|
"filtered": 100,
|
|
"attached_condition": "t2.a > '2018-06-01 23:59:59'",
|
|
"using_index": true
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
select count(*) from t2 where '2018-06-01' <= date(a);
|
|
count(*)
|
|
350
|
|
select count(*) from t2 where '2018-06-01' <= a;
|
|
count(*)
|
|
350
|
|
explain format=json select count(*) from t2 where '2018-06-01' <= date(a);
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.051773094,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t2",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "6",
|
|
"used_key_parts": ["a"],
|
|
"loops": 1,
|
|
"rows": 363,
|
|
"cost": 0.051773094,
|
|
"filtered": 100,
|
|
"attached_condition": "t2.a >= '2018-06-01 00:00:00'",
|
|
"using_index": true
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
select count(*) from t2 where '2017-06-02' = date(a);
|
|
count(*)
|
|
10
|
|
select count(*) from t2 where a >= '2017-06-02' and a < '2017-06-03';
|
|
count(*)
|
|
10
|
|
explain format=json select count(*) from t2 where '2017-06-02' = date(a);
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.002723384,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t2",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "6",
|
|
"used_key_parts": ["a"],
|
|
"loops": 1,
|
|
"rows": 10,
|
|
"cost": 0.002723384,
|
|
"filtered": 100,
|
|
"attached_condition": "t2.a between '2017-06-02 00:00:00' and '2017-06-02 23:59:59'",
|
|
"using_index": true
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
# Check rewrite of a more complicated query
|
|
explain format=json select * from t2 as t21 force index(a),
|
|
t2 as t22 force index(a)
|
|
where year(t21.a) < 2018 and t21.b > '2017-11-01'
|
|
and date(t22.a) >= '2017-02-01' and t22.b > '2017-11-01';
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 24.30027923,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t21",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "6",
|
|
"used_key_parts": ["a"],
|
|
"loops": 1,
|
|
"rows": 451,
|
|
"cost": 0.558056003,
|
|
"filtered": 56,
|
|
"index_condition": "t21.a < '2018-01-01 00:00:00'",
|
|
"attached_condition": "t21.b > '2017-11-01'"
|
|
}
|
|
},
|
|
{
|
|
"block-nl-join": {
|
|
"table": {
|
|
"table_name": "t22",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "6",
|
|
"used_key_parts": ["a"],
|
|
"loops": 252.56,
|
|
"rows": 961,
|
|
"cost": 23.74222323,
|
|
"filtered": 56,
|
|
"index_condition": "t22.a >= '2017-02-01 00:00:00'",
|
|
"attached_condition": "t22.a >= '2017-02-01 00:00:00' and t22.b > '2017-11-01'"
|
|
},
|
|
"buffer_type": "flat",
|
|
"buffer_size": "7Kb",
|
|
"join_type": "BNL",
|
|
"attached_condition": "t22.b > '2017-11-01'"
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
#
|
|
# Incorrect const values processing (no rewrite is possible)
|
|
#
|
|
explain format=json select * from t2 where year(a) = -1;
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.1671618,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t2",
|
|
"access_type": "ALL",
|
|
"loops": 1,
|
|
"rows": 1000,
|
|
"cost": 0.1671618,
|
|
"filtered": 100,
|
|
"attached_condition": "year(t2.a) = -1"
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
explain format=json select * from t2 where year(a) > -5;
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.1671618,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t2",
|
|
"access_type": "ALL",
|
|
"loops": 1,
|
|
"rows": 1000,
|
|
"cost": 0.1671618,
|
|
"filtered": 100,
|
|
"attached_condition": "year(t2.a) > -5"
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
explain format=json select * from t2 where year(a) < -1;
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.1671618,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t2",
|
|
"access_type": "ALL",
|
|
"loops": 1,
|
|
"rows": 1000,
|
|
"cost": 0.1671618,
|
|
"filtered": 100,
|
|
"attached_condition": "year(t2.a) < -1"
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
explain format=json select * from t2 where year(a) <= 10000;
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.1671618,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t2",
|
|
"access_type": "ALL",
|
|
"loops": 1,
|
|
"rows": 1000,
|
|
"cost": 0.1671618,
|
|
"filtered": 100,
|
|
"attached_condition": "year(t2.a) <= 10000"
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
explain format=json select * from t2 where year(a) >= 10020;
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.1671618,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t2",
|
|
"access_type": "ALL",
|
|
"loops": 1,
|
|
"rows": 1000,
|
|
"cost": 0.1671618,
|
|
"filtered": 100,
|
|
"attached_condition": "year(t2.a) >= 10020"
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
explain format=json select * from t2 where date(a) = '10000-01-01';
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.1671618,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t2",
|
|
"access_type": "ALL",
|
|
"loops": 1,
|
|
"rows": 1000,
|
|
"cost": 0.1671618,
|
|
"filtered": 100,
|
|
"attached_condition": "cast(t2.a as date) = '10000-01-01'"
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
Warnings:
|
|
Warning 1292 Incorrect datetime value: '10000-01-01'
|
|
explain format=json select * from t2 where date(a) < '-1-01-01';
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.1671618,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t2",
|
|
"access_type": "ALL",
|
|
"loops": 1,
|
|
"rows": 1000,
|
|
"cost": 0.1671618,
|
|
"filtered": 100,
|
|
"attached_condition": "cast(t2.a as date) < '-1-01-01'"
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
Warnings:
|
|
Warning 1292 Incorrect datetime value: '-1-01-01'
|
|
#
|
|
# Try DATE function and DATE (not DATETIME) column:
|
|
#
|
|
select count(*) from t2 where date(b)< '2017-06-03';
|
|
count(*)
|
|
220
|
|
select count(*) from t2 where b < '2017-06-03';
|
|
count(*)
|
|
220
|
|
explain format=json select count(*) from t2 where date(b)< '2017-06-03';
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.031207004,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t2",
|
|
"access_type": "range",
|
|
"possible_keys": ["b"],
|
|
"key": "b",
|
|
"key_length": "4",
|
|
"used_key_parts": ["b"],
|
|
"loops": 1,
|
|
"rows": 216,
|
|
"cost": 0.031207004,
|
|
"filtered": 100,
|
|
"attached_condition": "t2.b < '2017-06-03'",
|
|
"using_index": true
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
select count(*) from t2 where date(b)= '2017-06-04';
|
|
count(*)
|
|
10
|
|
select count(*) from t2 where b >= '2017-06-04' and b < '2017-06-05';
|
|
count(*)
|
|
10
|
|
explain format=json select count(*) from t2 where date(b)= '2017-06-04';
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.002723384,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t2",
|
|
"access_type": "range",
|
|
"possible_keys": ["b"],
|
|
"key": "b",
|
|
"key_length": "4",
|
|
"used_key_parts": ["b"],
|
|
"loops": 1,
|
|
"rows": 10,
|
|
"cost": 0.002723384,
|
|
"filtered": 100,
|
|
"attached_condition": "t2.b between '2017-06-04' and '2017-06-04'",
|
|
"using_index": true
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
#
|
|
# Check actual query results
|
|
#
|
|
insert into t2 values (10001,'2006-12-31 23:59:59','2006-12-31');
|
|
insert into t2 values (10002,'2007-01-01 00:00:00','2007-01-01');
|
|
insert into t2 values (10003,'2007-12-31 23:59:59','2007-12-31');
|
|
insert into t2 values (10004,'2008-01-01 00:00:00','2008-01-01');
|
|
explain format=json
|
|
select * from t2 force index(b) where year(b)=2007;
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.005042291,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t2",
|
|
"access_type": "range",
|
|
"possible_keys": ["b"],
|
|
"key": "b",
|
|
"key_length": "4",
|
|
"used_key_parts": ["b"],
|
|
"loops": 1,
|
|
"rows": 3,
|
|
"cost": 0.005042291,
|
|
"filtered": 100,
|
|
"index_condition": "t2.b between '2007-01-01' and '2007-12-31'"
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
select * from t2 force index(b) where year(b)=2007;
|
|
pk a b
|
|
10002 2007-01-01 00:00:00 2007-01-01
|
|
10003 2007-12-31 23:59:59 2007-12-31
|
|
insert into t2 values (10010,'2006-12-31 00:00:00','2006-12-31');
|
|
insert into t2 values (10011,'2006-12-30 23:59:59','2006-12-30');
|
|
explain format=json
|
|
select * from t2 force index(a) where date(a)='2006-12-31';
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.005042291,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t2",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "6",
|
|
"used_key_parts": ["a"],
|
|
"loops": 1,
|
|
"rows": 3,
|
|
"cost": 0.005042291,
|
|
"filtered": 100,
|
|
"index_condition": "t2.a between '2006-12-31 00:00:00' and '2006-12-31 23:59:59'"
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
select * from t2 force index(a) where date(a)='2006-12-31';
|
|
pk a b
|
|
10010 2006-12-31 00:00:00 2006-12-31
|
|
10001 2006-12-31 23:59:59 2006-12-31
|
|
#
|
|
# Test the TIMESTAMP column
|
|
#
|
|
create table t3 (a timestamp, b date, key(a));
|
|
# Insert data starting from 2016 since that year had a leap second
|
|
# (https://en.wikipedia.org/wiki/Leap_second)
|
|
set time_zone="UTC";
|
|
insert into t3
|
|
select
|
|
timestampadd(hour, B.a, date_add('2016-01-01', interval A.a*8 day)),
|
|
date_add('2016-01-01', interval A.a*7 day)
|
|
from t1 A, t0 B;
|
|
# Results of those two queries must be equal:
|
|
select count(*) from t3 force index(a) where year(a)= 2016;
|
|
count(*)
|
|
460
|
|
# The result must be the same as this query's:
|
|
select count(*) from t3 force index(a) where a >= '2016-01-01 00:00:00'
|
|
and a <= '2016-12-31 23:59:59.999999';
|
|
count(*)
|
|
460
|
|
explain format=json
|
|
select count(*) from t3 force index(a) where year(a)= 2016;
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.064493934,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t3",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "5",
|
|
"used_key_parts": ["a"],
|
|
"loops": 1,
|
|
"rows": 455,
|
|
"cost": 0.064493934,
|
|
"filtered": 100,
|
|
"attached_condition": "t3.a between '2016-01-01 00:00:00' and '2016-12-31 23:59:59'",
|
|
"using_index": true
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
set time_zone= @@global.time_zone;
|
|
#
|
|
# Incorrect const values processing (no rewrite is possible)
|
|
#
|
|
explain format=json select * from t2 where year(a) = -1;
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.1671618,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t2",
|
|
"access_type": "ALL",
|
|
"loops": 1,
|
|
"rows": 1000,
|
|
"cost": 0.1671618,
|
|
"filtered": 100,
|
|
"attached_condition": "year(t2.a) = -1"
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
explain format=json select * from t2 where year(a) > -5;
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.1671618,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t2",
|
|
"access_type": "ALL",
|
|
"loops": 1,
|
|
"rows": 1000,
|
|
"cost": 0.1671618,
|
|
"filtered": 100,
|
|
"attached_condition": "year(t2.a) > -5"
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
explain format=json select * from t2 where year(a) < -1;
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.1671618,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t2",
|
|
"access_type": "ALL",
|
|
"loops": 1,
|
|
"rows": 1000,
|
|
"cost": 0.1671618,
|
|
"filtered": 100,
|
|
"attached_condition": "year(t2.a) < -1"
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
explain format=json select * from t2 where year(a) <= 10000;
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.1671618,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t2",
|
|
"access_type": "ALL",
|
|
"loops": 1,
|
|
"rows": 1000,
|
|
"cost": 0.1671618,
|
|
"filtered": 100,
|
|
"attached_condition": "year(t2.a) <= 10000"
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
explain format=json select * from t2 where year(a) >= 10020;
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.1671618,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t2",
|
|
"access_type": "ALL",
|
|
"loops": 1,
|
|
"rows": 1000,
|
|
"cost": 0.1671618,
|
|
"filtered": 100,
|
|
"attached_condition": "year(t2.a) >= 10020"
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
explain format=json select * from t2 where date(a) = '10000-01-01';
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.1671618,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t2",
|
|
"access_type": "ALL",
|
|
"loops": 1,
|
|
"rows": 1000,
|
|
"cost": 0.1671618,
|
|
"filtered": 100,
|
|
"attached_condition": "cast(t2.a as date) = '10000-01-01'"
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
Warnings:
|
|
Warning 1292 Incorrect datetime value: '10000-01-01'
|
|
explain format=json select * from t2 where date(a) < '-1-01-01';
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.1671618,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t2",
|
|
"access_type": "ALL",
|
|
"loops": 1,
|
|
"rows": 1000,
|
|
"cost": 0.1671618,
|
|
"filtered": 100,
|
|
"attached_condition": "cast(t2.a as date) < '-1-01-01'"
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
Warnings:
|
|
Warning 1292 Incorrect datetime value: '-1-01-01'
|
|
#
|
|
# Composite indexes
|
|
#
|
|
create table t4 (a datetime, b int, key(a, b)) ;
|
|
insert into t4 values ('2009-11-29 13:43:32', 2);
|
|
insert into t4 values ('2009-10-15 12:15:11', 2);
|
|
insert into t4 values ('2009-09-01 15:55:00', 3);
|
|
insert into t4 values ('2009-08-23 12:07:47', 4);
|
|
explain format=json select * from t4 where year(a) = 2009;
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.001893764,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t4",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "6",
|
|
"used_key_parts": ["a"],
|
|
"loops": 1,
|
|
"rows": 4,
|
|
"cost": 0.001893764,
|
|
"filtered": 100,
|
|
"attached_condition": "t4.a between '2009-01-01 00:00:00' and '2009-12-31 23:59:59'",
|
|
"using_index": true
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
explain format=json select * from t4 where year(a) >= 2009;
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.001893764,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t4",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "6",
|
|
"used_key_parts": ["a"],
|
|
"loops": 1,
|
|
"rows": 4,
|
|
"cost": 0.001893764,
|
|
"filtered": 100,
|
|
"attached_condition": "t4.a >= '2009-01-01 00:00:00'",
|
|
"using_index": true
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
explain format=json select * from t4 where year(a) < 2018;
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.001893764,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t4",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "6",
|
|
"used_key_parts": ["a"],
|
|
"loops": 1,
|
|
"rows": 4,
|
|
"cost": 0.001893764,
|
|
"filtered": 100,
|
|
"attached_condition": "t4.a < '2018-01-01 00:00:00'",
|
|
"using_index": true
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
explain format=json select * from t4 where date(a) = '2009-12-01';
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.001478954,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t4",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "6",
|
|
"used_key_parts": ["a"],
|
|
"loops": 1,
|
|
"rows": 1,
|
|
"cost": 0.001478954,
|
|
"filtered": 100,
|
|
"attached_condition": "t4.a between '2009-12-01 00:00:00' and '2009-12-01 23:59:59'",
|
|
"using_index": true
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
explain format=json select * from t4 where b = 2 and year(a) = 2009;
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.001893764,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t4",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "11",
|
|
"used_key_parts": ["a", "b"],
|
|
"loops": 1,
|
|
"rows": 4,
|
|
"cost": 0.001893764,
|
|
"filtered": 100,
|
|
"attached_condition": "t4.b = 2 and t4.a between '2009-01-01 00:00:00' and '2009-12-31 23:59:59'",
|
|
"using_index": true
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
explain format=json select * from t4 where b = 10 and year(a) > 2001;
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.001893764,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t4",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "6",
|
|
"used_key_parts": ["a"],
|
|
"loops": 1,
|
|
"rows": 4,
|
|
"cost": 0.001893764,
|
|
"filtered": 100,
|
|
"attached_condition": "t4.b = 10 and t4.a > '2001-12-31 23:59:59'",
|
|
"using_index": true
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
explain format=json select * from t4 where b = 2 and date(a) = '2009-11-02';
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.001478954,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t4",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "11",
|
|
"used_key_parts": ["a", "b"],
|
|
"loops": 1,
|
|
"rows": 1,
|
|
"cost": 0.001478954,
|
|
"filtered": 100,
|
|
"attached_condition": "t4.b = 2 and t4.a between '2009-11-02 00:00:00' and '2009-11-02 23:59:59'",
|
|
"using_index": true
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
# Reverse order of fields in the index
|
|
create table t5 (a datetime, b int, c varchar(20), key(b, a));
|
|
insert into t5 values ('2009-11-29 13:43:32', 2, 'abc');
|
|
insert into t5 values ('2009-10-15 12:15:11', 2, 'def');
|
|
insert into t5 values ('2009-09-01 15:55:00', 3, 'gfd');
|
|
insert into t5 values ('2009-08-23 12:07:47', 4, 'xyz');
|
|
explain format=json select * from t5 where year(a) = 2009;
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.01066122,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t5",
|
|
"access_type": "ALL",
|
|
"loops": 1,
|
|
"rows": 4,
|
|
"cost": 0.01066122,
|
|
"filtered": 100,
|
|
"attached_condition": "t5.a between <cache>('2009-01-01 00:00:00') and <cache>('2009-12-31 23:59:59')"
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
explain format=json select * from t4 where date(a) = '2009-12-01';
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.001478954,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t4",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "6",
|
|
"used_key_parts": ["a"],
|
|
"loops": 1,
|
|
"rows": 1,
|
|
"cost": 0.001478954,
|
|
"filtered": 100,
|
|
"attached_condition": "t4.a between '2009-12-01 00:00:00' and '2009-12-01 23:59:59'",
|
|
"using_index": true
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
explain format=json select * from t5 where b = 2 and year(a) = 2009;
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.002037211,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t5",
|
|
"access_type": "range",
|
|
"possible_keys": ["b"],
|
|
"key": "b",
|
|
"key_length": "11",
|
|
"used_key_parts": ["b", "a"],
|
|
"loops": 1,
|
|
"rows": 2,
|
|
"cost": 0.002037211,
|
|
"filtered": 70,
|
|
"index_condition": "t5.b = 2 and t5.a between '2009-01-01 00:00:00' and '2009-12-31 23:59:59'"
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
explain format=json select * from t5 where b = 10 and year(a) > 2001;
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.002574553,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t5",
|
|
"access_type": "range",
|
|
"possible_keys": ["b"],
|
|
"key": "b",
|
|
"key_length": "11",
|
|
"used_key_parts": ["b", "a"],
|
|
"loops": 1,
|
|
"rows": 1,
|
|
"cost": 0.002574553,
|
|
"filtered": 100,
|
|
"index_condition": "t5.b = 10 and t5.a > '2001-12-31 23:59:59'"
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
explain format=json select * from t5 where b = 3 and date(a) > '2009-09-01';
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.002574553,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t5",
|
|
"access_type": "range",
|
|
"possible_keys": ["b"],
|
|
"key": "b",
|
|
"key_length": "11",
|
|
"used_key_parts": ["b", "a"],
|
|
"loops": 1,
|
|
"rows": 1,
|
|
"cost": 0.002574553,
|
|
"filtered": 100,
|
|
"index_condition": "t5.b = 3 and t5.a > '2009-09-01 23:59:59'"
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
#
|
|
# No rewrite for a non-indexed column
|
|
#
|
|
create table t6 (a datetime);
|
|
insert into t6 values ('2009-11-29 13:43:32');
|
|
insert into t6 values ('2009-10-15 12:15:11');
|
|
insert into t6 values ('2009-09-01 15:55:00');
|
|
insert into t6 values ('2009-08-23 12:07:47');
|
|
explain format=json select * from t6 where year(a) = 2009;
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.01066122,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t6",
|
|
"access_type": "ALL",
|
|
"loops": 1,
|
|
"rows": 4,
|
|
"cost": 0.01066122,
|
|
"filtered": 100,
|
|
"attached_condition": "year(t6.a) = 2009"
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
explain format=json select * from t6 where date(a) = '2009-12-01';
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.01066122,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t6",
|
|
"access_type": "ALL",
|
|
"loops": 1,
|
|
"rows": 4,
|
|
"cost": 0.01066122,
|
|
"filtered": 100,
|
|
"attached_condition": "cast(t6.a as date) = '2009-12-01'"
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
drop table t0,t1,t2,t3,t4,t5,t6;
|
|
drop view v1;
|
|
drop procedure sp;
|
|
#
|
|
# MDEV-30946 Index usage for DATE(datetime_column) = const
|
|
# does not work for DELETE and UPDATE
|
|
#
|
|
create table t1 (pk int primary key, a datetime, c int, key(a));
|
|
insert into t1 (pk,a,c) values (1,'2009-11-29 13:43:32', 2);
|
|
insert into t1 (pk,a,c) values (2,'2009-11-29 03:23:32', 2);
|
|
insert into t1 (pk,a,c) values (3,'2009-10-16 05:56:32', 2);
|
|
insert into t1 (pk,a,c) values (4,'2010-11-29 13:43:32', 2);
|
|
insert into t1 (pk,a,c) values (5,'2010-10-16 05:56:32', 2);
|
|
insert into t1 (pk,a,c) values (6,'2011-11-29 13:43:32', 2);
|
|
insert into t1 (pk,a,c) values (7,'2012-10-16 05:56:32', 2);
|
|
# YEAR() conditions, UPDATE
|
|
explain format=json update t1 set c = 0 where year(a) = 2010;
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"table": {
|
|
"update": 1,
|
|
"table_name": "t1",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "6",
|
|
"used_key_parts": ["a"],
|
|
"rows": 2,
|
|
"attached_condition": "t1.a between '2010-01-01 00:00:00' and '2010-12-31 23:59:59'"
|
|
}
|
|
}
|
|
}
|
|
update t1 set c = 0 where year(a) = 2010;
|
|
select * from t1;
|
|
pk a c
|
|
1 2009-11-29 13:43:32 2
|
|
2 2009-11-29 03:23:32 2
|
|
3 2009-10-16 05:56:32 2
|
|
4 2010-11-29 13:43:32 0
|
|
5 2010-10-16 05:56:32 0
|
|
6 2011-11-29 13:43:32 2
|
|
7 2012-10-16 05:56:32 2
|
|
explain format=json update t1 set c = 1
|
|
where c < (select count(*) from t1 where year(a) = 2010);
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.011130435,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t1",
|
|
"access_type": "ALL",
|
|
"loops": 1,
|
|
"rows": 7,
|
|
"cost": 0.011130435,
|
|
"filtered": 100,
|
|
"attached_condition": "t1.c < (subquery#2)"
|
|
}
|
|
}
|
|
],
|
|
"subqueries": [
|
|
{
|
|
"query_block": {
|
|
"select_id": 2,
|
|
"cost": 0.001617224,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t1",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "6",
|
|
"used_key_parts": ["a"],
|
|
"loops": 1,
|
|
"rows": 2,
|
|
"cost": 0.001617224,
|
|
"filtered": 100,
|
|
"attached_condition": "t1.a between '2010-01-01 00:00:00' and '2010-12-31 23:59:59'",
|
|
"using_index": true
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
explain format=json update t1 set c = 0
|
|
where year(a) = 2010 and c < (select count(*) from t1 where year(a) = 2010);
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.003808422,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t1",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "6",
|
|
"used_key_parts": ["a"],
|
|
"loops": 1,
|
|
"rows": 2,
|
|
"cost": 0.003808422,
|
|
"filtered": 100,
|
|
"index_condition": "t1.a between '2010-01-01 00:00:00' and '2010-12-31 23:59:59'",
|
|
"attached_condition": "t1.c < (subquery#2)"
|
|
}
|
|
}
|
|
],
|
|
"subqueries": [
|
|
{
|
|
"query_block": {
|
|
"select_id": 2,
|
|
"cost": 0.001617224,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t1",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "6",
|
|
"used_key_parts": ["a"],
|
|
"loops": 1,
|
|
"rows": 2,
|
|
"cost": 0.001617224,
|
|
"filtered": 100,
|
|
"attached_condition": "t1.a between '2010-01-01 00:00:00' and '2010-12-31 23:59:59'",
|
|
"using_index": true
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
# Multi-table update
|
|
create table t2 (a int);
|
|
insert into t2 values (4),(5),(6);
|
|
explain format=json update t1, t2 set c = 0
|
|
where year(t1.a) = 2010 and t1.c = t2.a;
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.014992165,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t1",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "6",
|
|
"used_key_parts": ["a"],
|
|
"loops": 1,
|
|
"rows": 2,
|
|
"cost": 0.003808422,
|
|
"filtered": 100,
|
|
"attached_condition": "t1.a between '2010-01-01 00:00:00' and '2010-12-31 23:59:59'"
|
|
}
|
|
},
|
|
{
|
|
"table": {
|
|
"table_name": "t2",
|
|
"access_type": "ALL",
|
|
"loops": 2,
|
|
"rows": 3,
|
|
"cost": 0.011183743,
|
|
"filtered": 100,
|
|
"attached_condition": "t2.a = t1.c"
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
prepare stmt from "update t1 set c = 0 where year(a) = 2010";
|
|
execute stmt;
|
|
execute stmt;
|
|
# YEAR() conditions, DELETE
|
|
explain format=json delete from t1 where year(a) = 2010;
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"table": {
|
|
"delete": 1,
|
|
"table_name": "t1",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "6",
|
|
"used_key_parts": ["a"],
|
|
"rows": 2,
|
|
"attached_condition": "t1.a between '2010-01-01 00:00:00' and '2010-12-31 23:59:59'"
|
|
}
|
|
}
|
|
}
|
|
delete from t1 where year(a) = 2010;
|
|
select * from t1;
|
|
pk a c
|
|
1 2009-11-29 13:43:32 2
|
|
2 2009-11-29 03:23:32 2
|
|
3 2009-10-16 05:56:32 2
|
|
6 2011-11-29 13:43:32 2
|
|
7 2012-10-16 05:56:32 2
|
|
explain format=json delete from t1
|
|
where c < (select count(*) from t1 where year(a) = 2010);
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"cost": 0.010817625,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t1",
|
|
"access_type": "ALL",
|
|
"loops": 1,
|
|
"rows": 5,
|
|
"cost": 0.010817625,
|
|
"filtered": 100,
|
|
"attached_condition": "t1.c < (subquery#2)"
|
|
}
|
|
}
|
|
],
|
|
"subqueries": [
|
|
{
|
|
"query_block": {
|
|
"select_id": 2,
|
|
"cost": 0.001478954,
|
|
"nested_loop": [
|
|
{
|
|
"table": {
|
|
"table_name": "t1",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "6",
|
|
"used_key_parts": ["a"],
|
|
"loops": 1,
|
|
"rows": 1,
|
|
"cost": 0.001478954,
|
|
"filtered": 100,
|
|
"attached_condition": "t1.a between '2010-01-01 00:00:00' and '2010-12-31 23:59:59'",
|
|
"using_index": true
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
delete from t1 where c < (select count(*) from t1 where year(a) = 2010);
|
|
prepare stmt from "delete from t1 where year(a) = 2009";
|
|
execute stmt;
|
|
execute stmt;
|
|
select * from t1;
|
|
pk a c
|
|
6 2011-11-29 13:43:32 2
|
|
7 2012-10-16 05:56:32 2
|
|
# DATE() conditions, UPDATE
|
|
explain format=json update t1 set c = 0 where date(a) = '2010-10-16';
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"table": {
|
|
"update": 1,
|
|
"table_name": "t1",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "6",
|
|
"used_key_parts": ["a"],
|
|
"rows": 1,
|
|
"attached_condition": "t1.a between '2010-10-16 00:00:00' and '2010-10-16 23:59:59'"
|
|
}
|
|
}
|
|
}
|
|
explain format=json update t1 set c = 0 where date(a) <= '2011-10-16';
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"table": {
|
|
"update": 1,
|
|
"table_name": "t1",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "6",
|
|
"used_key_parts": ["a"],
|
|
"rows": 1,
|
|
"attached_condition": "t1.a <= '2011-10-16 23:59:59'"
|
|
}
|
|
}
|
|
}
|
|
prepare stmt from "update t1 set c = 3 where date(a) = '2011-11-29'";
|
|
execute stmt;
|
|
execute stmt;
|
|
select * from t1;
|
|
pk a c
|
|
6 2011-11-29 13:43:32 3
|
|
7 2012-10-16 05:56:32 2
|
|
# DATE() conditions, DELETE
|
|
explain format=json delete from t1 where date(a) = '2010-10-16';
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"table": {
|
|
"delete": 1,
|
|
"table_name": "t1",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "6",
|
|
"used_key_parts": ["a"],
|
|
"rows": 1,
|
|
"attached_condition": "t1.a between '2010-10-16 00:00:00' and '2010-10-16 23:59:59'"
|
|
}
|
|
}
|
|
}
|
|
explain format=json delete from t1 where date(a) <= '2011-10-16';
|
|
EXPLAIN
|
|
{
|
|
"query_block": {
|
|
"select_id": 1,
|
|
"table": {
|
|
"delete": 1,
|
|
"table_name": "t1",
|
|
"access_type": "range",
|
|
"possible_keys": ["a"],
|
|
"key": "a",
|
|
"key_length": "6",
|
|
"used_key_parts": ["a"],
|
|
"rows": 1,
|
|
"attached_condition": "t1.a <= '2011-10-16 23:59:59'"
|
|
}
|
|
}
|
|
}
|
|
prepare stmt from "delete from t1 where date(a) <= '2012-01-01'";
|
|
execute stmt;
|
|
execute stmt;
|
|
select * from t1;
|
|
pk a c
|
|
7 2012-10-16 05:56:32 2
|
|
# Test partition pruning
|
|
create table t3 (
|
|
a datetime,
|
|
key(a)
|
|
) partition by range(year(a)) (
|
|
partition p0 values less than (2022),
|
|
partition p1 values less than (MAXVALUE)
|
|
);
|
|
insert into t3
|
|
select date_add('2020-01-01', interval seq*10 day)
|
|
from seq_1_to_100;
|
|
# Must be only "p0" partition
|
|
explain partitions select * from t3 where year(a) = 2020;
|
|
id select_type table partitions type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t3 p0 range a a 6 NULL 36 Using where; Using index
|
|
explain partitions delete from t3 where year(a) = 2020;
|
|
id select_type table partitions type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t3 p0 ALL a NULL NULL NULL 73 Using where
|
|
explain partitions update t3 set a = a + 1 where year(a) = 2020;
|
|
id select_type table partitions type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t3 p0 ALL a NULL NULL NULL 73 Using where; Using buffer
|
|
drop tables t1,t2,t3;
|