[MySQL] InnoDB logical Storage Structure

[MySQL] the InnoDB logical storage structure the tables in the InnoDB Storage engine are very similar to the index organization tables in Oracle. Each table must have a primary key. If the table is not displayed when it is created, the primary key is automatically created according to the following principles: 1) if a unique index is not empty, the column where the index is located is the primary key; 2) if the preceding conditions are not met, automatically create a six-byte pointer as the primary key. The logical storage structure of the InnoDB Storage engine is almost the same as that of Oracle, ranging from large to small: tablespace, segment, partition, and page. Their relationships are shown in: in the previous article "MySQL InnoDB file Introduction. It should be noted that innodb_file_per_table is enabled in real time, and not all data in the table is stored in its own tablespace separately. Only data, indexes, and insertion buffering are stored in the tablespace separately, others such as Undo, system transaction information, and secondary write buffering are stored in the default shared tablespace. Segment tablespace consists of several segments, including data segments, index segments, and rollback segments. The table in InnoDB is an index organization table. Therefore, the data segment is also called the leaf node segment, and the index segment is also called the non-leaf node segment. The partition consists of 64 consecutive pages, so the partition size is exactly 1 MB. The page is the minimum unit for InnoDB disk management. The fixed size is 16 KB and cannot be changed (you can change the fixed size by changing the source code ). Data in the row InnoDB table is stored by row.