Re: FoxPro Vs. PostgreSQL
От | William Yu |
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Тема | Re: FoxPro Vs. PostgreSQL |
Дата | |
Msg-id | brkpic$27v$1@news.hub.org обсуждение исходный текст |
Ответ на | Re: FoxPro Vs. PostgreSQL (Sai Hertz And Control Systems <sank89@sancharnet.in>) |
Список | pgsql-general |
Sai Hertz And Control Systems wrote: > This was great help loads of thanks > Now its upto me to convert it into laymans language. Those limitations don't really describe what the real problems of FoxPro are. I've used FoxPro since the days it was a product of Fox Corporation so I know indepth all the issues. The biggest problem: completely and absolutely multi-user unsafe. If two machines try to update the same record and append to the safe table, one of the following things may occur: 1) One machine gets stuck "waiting to lock" and never ever ever comes back to life. 70% 2) FoxPro on one or both machines immediately crashes with a Windows exception error. 25% 3) Indexes get corrupted 4% 4) A garbage record is inserted 1% There is a way to solve the multi-user problem but it requires you to write your own table/record locking mechanisms. Basically, if you try to use FoxPro's RLOCK() or LOCK(), you are screwed. However, exclusive file handles on a shared network drive seemed pretty solid. (My experience on SAMBA, Netware and NT server -- dunno about Win98 file sharing though.) You just suffer a huge performance penalty as file creation/directory scanning incurs a high overhead. You also run the risk where if your code doesn't release locks, nobody else could ever do any transactions since they aren't auto released when a table is closed or a record pointer moved. Indexes also always get corrupted sooner or later whenever you exceed a table size threshold. Corruption of indexes will exhibit the following symptoms: 1) Searches get stuck in infinite loops 60% 2) Searches return the wrong results 30% 3) FoxPro crahses with a Windows exception error 5% 4) FoxPro just simply shuts down without any notification 5% Now, that being said, we still use FoxPro at our company. There are some things it is really good for like processing & manipulating bulk data. If I had to use perl or java or whatever to process comma delimited files or badly maintained excel spreadsheets, I would go nuts. There's just so many commands for manipulating data that make life much easier. We then use ODBC to update the "final" versions residing on Postgresql.
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