web applications - Technologies allowing to store user data on server as well as on user's PC? -

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let me first better explain context. application should have following characteristics:

  • read-only shared data found on database server on internet. (quite big amount of shared data.)
  • the application should distributed in java-web-start-like manner, or web application. (the goal simplify distribution of main package , updates. solutions lowering server load , giving better responsiveness end user preferred.)
  • it must possible store user specific data on server, on user's pc, or on both. (the reason users not willing risk having information out of pc, of them share parts of or make backups.)

i'm not knowledgeable in web application programming. technology know allow java web start. removes load server computations done on user side, allows read/write on user's pc (given access) , accessing centralized database not problem it.

i know if there other technologies allow development of such application , not require traditional local installation.

thank much,

mj

it depends:

  • volume, size, complexity of data/data model,
  • frequency, urgency of updates,
  • available connectivity (online 24/7 vs. occasionaly connected vs. nightly sync session) , bandwidth,
  • existing mechanisms data storage,
  • amount of software may/can/want deploy on clients,
  • available budget,
  • acceptable dev time
  • resources , organization available operate system
  • lifecycle plan (expected lifetime) of system,
  • mission significance (mission-critical system can kill lifes, vs. "just" manager info system)

are factors should mention, or @ least evaluate. depending on these aspects, solution can vary "cheap" webservice , flat files sync'd trivial java code full-flat distributed database.

years ago, have found sybase's sql anywhere solution small-to-medium requirements , budgets if "real" sql dbms required, or present on server backend side. offers powerful, yet transparent (if used wisely) publish-and-subscribe methodology @ sql level works if cannot sure clients online 24/7.

for online (or almost-online) full-fledged solutions, oracle has online database replication options quite expensive, though.

for small solutions, custom java code accessing remote database links (oracle feature) works, locating performance bottlenecks can nightmare. (and require stable network links, , "real" oracle database on nodes.)


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