System table space

As you can see, the first three pages (page number 0, page number 1, page number 2, type FSP_HDR, IBUF_BITMAP, INODE) of the system tablespace and independent tablespace are of the same type.Only pages with page numbers 3 through 7 are unique to the system table space

  • Page Number 3 SYS: Insert Buffer Header Stores the Header information of the Insert Buffer
  • Page number 4 INDEX: Insert Buffer Root The Root page for storing the Insert Buffer
  • Page 5 TRX_SYS: Information about Transction System transactions
  • Page 6 SYS: First Rollback Segment Specifies the First Rollback Segment
  • Page no. 7 SYS: Data Dictionary Header Indicates the Header of the Data Dictionary

1.SYS: Data Dictionary Header

Record the B+ tree positions of the clustered indexes and secondary indexes of the four tables (SYS_TABLES, SYS_COLUMNS, SYS_INDEXES, and SYS_FIELDS). Having the four basic system tables above means that you can retrieve all metadata for other system tables as well as user-defined tables.

Alter table SYS_TABLESPACES; alter table SYS_TABLESPACES; alter table SYS_TABLESPACES;

  1. To obtain the TABLE_ID of the SYS_TABLESPACES table, locate the specific record in the SYS_TABLES table based on the table name

  2. Use this TABLE_ID into the SYS_COLUMNS table to get information about all the columns that belong to the table.

  3. Select * from SYS_INDEXES; select * from SYS_INDEXES; select * from SYS_INDEXES; select * from SYS_INDEXES; select * from SYS_INDEXES;

  4. Use INDEX_ID to retrieve information for all index columns in the SYS_FIELDS table.

1.1 the File Header

Record some general information about the page

1.2 Data Dictionary Header

Records the root page location of some basic system tables and some global information about the InnoDB storage engine

1.3 the Segment Header

Record the INODE Entry position corresponding to the segment on the page

1.4 the Empty Space

Padding for page structures, no real meaning

1.5 the File Trailer

Verify page integrity