Several commands not commonly used in MySQL

1、 see B+ The number of highly

SELECT b.name, a.name, index_id, type, a.space, a.PAGE_NO

FROM information_schema.INNODB_SYS_INDEXES a,

information_schema.INNODB_SYS_TABLES b

WHERE a.table_id = b.table_id AND a.space <> 0;

among PAGE_NO The height of the tree is .

2、 Compress data pages

ALTER TABLE Transaction202102 COMPRESSION=ZLIB;

OPTIMIZE TABLE Transaction202102;