Details
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Bug
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Status: Closed (View Workflow)
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Major
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Resolution: Fixed
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10.1(EOL)
Description
EXPLAIN FORMAT=JSON (and ANALYZE FORMAT=JSON too) do not show used partitions.
create table ten(a int);
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insert into ten values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
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create table t10 (
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a int not null
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) partition by key(a);
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insert into t10 select a from ten;
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explain partitions select * from t10 where a in (2,3,4);
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EXPLAIN PARTITIONS shows:
MariaDB [j2]> explain partitions select * from t10 where a in (2,3,4);
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+------+-------------+-------+------------+------+---------------+------+---------+------+------+-------------+
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| id | select_type | table | partitions | type | possible_keys | key | key_len | ref | rows | Extra |
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+------+-------------+-------+------------+------+---------------+------+---------+------+------+-------------+
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| 1 | SIMPLE | t10 | p0 | ALL | NULL | NULL | NULL | NULL | 10 | Using where |
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+------+-------------+-------+------------+------+---------------+------+---------+------+------+-------------+
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EXPLAIN FORMAT=JSON doesn't show partitions:
MariaDB [j2]> explain format=json select * from t10 where a in (2,3,4)\G
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*************************** 1. row ***************************
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EXPLAIN: {
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"query_block": {
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"select_id": 1,
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"table": {
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"table_name": "t10",
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"access_type": "ALL",
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"rows": 10,
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"filtered": 100,
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"attached_condition": "(t10.a in (2,3,4))"
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}
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}
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}
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For comparison, MySQL 5.6 shows:
MySQL [test]> explain format=json select * from t10 where a in (2,3,4)\G
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*************************** 1. row ***************************
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EXPLAIN: {
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"query_block": {
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"select_id": 1,
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"table": {
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"table_name": "t10",
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"partitions": [
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"p0"
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],
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"access_type": "ALL",
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"rows": 10,
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"filtered": 100,
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"attached_condition": "(`test`.`t10`.`a` in (2,3,4))"
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}
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}
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}
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