MySQL Limit optimization method

MySQL Limit optimization method

SELECT * FROM table LIMIT [offset,] rows | Rows Offset Offset

The LIMIT clause can be used to force a SELECT statement to return the specified number of records. LIMIT accepts one or two numeric parameters. parameter must be an integer constant. Given two parameters, the first parameter specifies the offset of the first row to return the record, and the second parameter specifies the maximum number of rows to be returned. The offset of the initial record line is 0 (instead of 1): In order to be compatible with PostgreSQL, MySQL also supports syntax: LIMIT # offset #.

Mysql> SELECT * FROM table LIMIT 5, 10; Retrieve Record Row 6-15

To retrieve all row rows from an offset to the end of a recordset, you can specify a second argument of-1:
Mysql> SELECT * from table LIMIT 95,-1; Retrieves the record row 96-last.

If only one argument is given, it represents the maximum number of record rows returned:
Mysql> SELECT * from table LIMIT 5; Retrieve the first 5 rows of records

In other words, LIMIT n is equivalent to LIMIT 0,n.

Select * FROM Cyclopedia Where id>= (
Select Max (ID) from (
Select ID from Cyclopedia order by ID limit 90001
) as TMP
) limit 100;

2.
Select * FROM Cyclopedia Where id>= (
Select Max (ID) from (
Select ID from Cyclopedia order by ID limit 90000,1
) as TMP
) limit 100;

Also take 90,000 after 100 records, the 1th sentence is fast or 2nd sentence fast?
The 1th sentence is to take the first 90,001 records, take one of the largest ID value as the starting ID, and then use it to quickly locate the next 100 records
The 2nd option is to take only 90,000 records after 1, and then take the ID value as the starting mark to locate the next 100 records
The 1th sentence executes the result. Rows in Set (0.23) sec
The 2nd sentence executes the result. Rows in Set (0.19) sec

It is clear that the 2nd sentence wins. Looks like limit wasn't exactly what I thought it would be. Full-table scans return limit Offset+length records, which seems to improve the limit compared to Ms-sql's top performance.

In fact, the 2nd sentence can be simply simplified into

Select * FROM Cyclopedia Where id>= (
Select ID from Cyclopedia limit 90000,1
) limit 100;

Using the ID of the No. 90000 record directly, without the max operation, this is theoretically more efficient, but in practice it is almost invisible, because the location ID returns 1 records, and Max does not have to work to get the results, but this is clearer and clearer, eliminating the foot of the snake painting.

However, since MySQL has limit can directly control the location of the record, why not simply use the SELECT * from Cyclopedia limit 90000,1? Is it simpler?