I'm not very familiar with SQL, but think this is a common problem with
databases treating "real-time data".
I have an application which is being updated with prices from the
I'd like the client application which retrieves this data from the
database not to have to do repeated SELECTs to determine when the data
changes, but to somehow have a way to be advised that a table has
I think triggers can be used to perform calculations/functions on the data
in the database (as inserts/updates take place) which would solve most of
my problems, but I still need the "client" to know when the data changes.
If I want to cope with "real-time" (sub 1 second) updates for a number of
clients frequent SELECTS will presumably cause a severe load on the
server, which I'd prefer to avoid.
For the time being I can afford to "poll" every 10-30 seconds.
How is this problem solved in other "big" databases, and are there
facilities for doing this in MySQL? (Presumably this isn't standard SQL)
Server version 3.22.16a-gamma
Protocol version 10
Connection mysql via TCP/IP
TCP port 3306
Uptime: 4 days 16 hours 38 min 0 sec
on Solaris 2.6 with clients using ODBC running Visual Basic :-(
Thanks for any pointers on the subject.
Simon Mudd ******** All Trading Brokers Europe ********* Madrid, Spain
Switchboard: +34-91-592 8188 Fax: +34-91-592 8170 Direct: 91-592 8250
Work email: simon.mudd@stripped --- Home email: sjmudd@stripped