"Hey dude wheres my business logic"
We started with a look back at the good old days:
Things have changed a lot since 1978. Over the years, the hardware has moved from the desktop model to client server to 3-tier to n-tierProcedural. Software on the other hand has moved prom procedural to OOP to SOA.
Peoples perception of what constitutes a "big" system often differs considerably. To some people a big system may be 100 users. To others, it may be tens of thousands. Scalability is one of the top issues in system deployment - small can grow unexpectedly - and this is never a good time to rebuild.
By way of disclaimer, the speaker offered us a warning "This session will be contriversial!"
"where is your business logic?" exclaims the speaker, "I will show you instances where it is either on the client and the databas server."
After a brief defenition of what the speaker means by tier and layer, we continued on the road of Business Logic (BL).
The old desktop applications contained 100% business logic with little or no seperation between the application layers. Once evolution to the 2-tier client/server model took place, we automatically had that seperation between the application and storage layers. However, the client retained intermixed business logic. When coupled with the network limitations of the time (i.e. high network usage, low lan speeds), bottlenecks were bound to ensue.
Applications evolved with a large amount of BL being moved to server which is good but the choice of migrating to the database (usually via stored procedures) was bad.
The speaker asked for a show of hands as how many of us know of a "monster" stored procedure in existance within their organisation. We were told why such stored procedures are often a bad thing i.e.interpreted which is slow, inefficient, large number of conditional statements which has a performance cost etc.
more to follow ...
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