Hello Dipen, I think what he meant is that if power is off the last transaction is trashed, but your index is not.
Best. On Mon, Sep 15, 2008 at 10:55 PM, Dipen <[EMAIL PROTECTED]> wrote: > hi michael, > this is rather hard for me to understand, if a system loses power > (electricity), how can it be ensured that fsync() call will happen at all, > this commit function relies on fsync() but what if OS doesnt have time or > power in this case to actually call fsync() and synchronize. I read about > fsync() long time bacck and had this same question. > > Is there anything like ultimate transaction preservation procedure as a > state of no power is almost unpedictable and unplannable. This is rather > silly question I know, but just coz you mentioned and I happened to read, I > wouldn loose this opportunity to ask this :) > > thanks > > On Tue, Sep 16, 2008 at 12:18 AM, Michael McCandless < > [EMAIL PROTECTED]> wrote: > >> >> There is no difference, unless your computer/OS crashes or loses power >> shortly after you had call the method. >> >> In that case, there's a big difference: commit() guarantees your index will >> be intact (assuming the storage system holding your index was not damaged) >> but with flush(), which doesn't sync() the index files it writes, it's >> entirely possible that the index will become corrupt because some files were >> still in the OS's write cache when it crashed. >> >> But the guarantee only holds if the underlying storage system is "honest" >> about fsync(), ie, it truly flushes all written bytes for that file to disk >> before returning. >> >> Mike >> >> >> Cam Bazz wrote: >> >> Hello, >>> >>> What is the difference between flush in <2.4 and commit? >>> >>> Also I have been looking over docs, and they mention commit(long) but >>> there is no commit(long) method but only commit() >>> >>> Best. >>> >>> --------------------------------------------------------------------- >>> To unsubscribe, e-mail: [EMAIL PROTECTED] >>> For additional commands, e-mail: [EMAIL PROTECTED] >>> >>> >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: [EMAIL PROTECTED] >> For additional commands, e-mail: [EMAIL PROTECTED] >> >> > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
