mysql-indexing technique for left-prefixed columns that are not easily distinguishable

Example: http://www.sina.com,http://www.baidu.com

The first 10 characters are the same, indexing starts with the 11th character and is a waste of resources. Here are two tips to solve this problem:

1. Reverse

Sort data in reverse order: moc.anis.www//:p TTH, so the invalid length is reduced when indexing is established.

2. Pseudo-hashing techniques

The IP address we stored in the database is as follows,

ID URL

1 http://www.baidu.com

Now change the table structure to the following:

ID URL URLCRC

1 http://www.baidu.com 9900090-90-8

Where URLCRC is the value computed from the PHP built-in function CRC32. Where CRC32 is a hashing algorithm that can count strings as 32-bit integers.

mysql-indexing technique for left-prefixed columns that are not easily distinguishable