Greetings,
I have a table with millions of data with this structure:
callrequest (
serialno varchar(20) default '0',
callno varchar(20) default null
). Currently this table has no callno for some of the records

Another temporary table with the same structure, holds a temporary data around 100K records, and this data will be purged daily, as data keeps on coming everyday around 100K and update callno in the main table


How can i do that with a very efficient way. Thank you

have you seen the multi-table UPDATE syntax in the manual? that will do what you want