ODBC Oracle connection loses connectivity overnight
Posted on 2009-02-10
Hi this is a non urgent question but one which has foxed me for a long time...
I'm maintaining a certain number of Access databases for a department in a large company. Most of these databases link to Oracle via ODBC using Oracle in OraHome 9201 or 901. What sometimes happens is that when these databases are left on overnight, the next day when the user attempts some kind of processing the user gets a connectivity problem and attempting to reconnect the Oracle tables either via code or the 'get external data' feaure in Access results in some kind of access denied error. This seems especially true if the account is read/write. Even recreating the DSN has no effect, and the only cure seems to be to re-boot the PC.
Non-ODBC applications e.g. TOAD remain unaffected.
My theory is that because the Oracle database undergoes data import overnight it locks out read-write accounts and somehow ODBC doesn't have the nounce to realise that the lock has been released ... but I'm just clutching at straws. Does anyone else have any experience of this phenomenon or have any explanation why it occurs or how it may be circumvented ?