statistics update has too many conflicts

[coocood]

We periodically update mysql.stats_histogram table, execute update statements for each column in the table in a transaction.

If the table has many columns, the transaction will take a long time to commit, the chance of write-conflict is high.

One way to solve the problem is to first select all histogram for a table in mysql.stats_histogram, then use insert on duplicate update statement to update the rows.