dbexport.

On 10-07-92 David Kosenko writes: |In article <9655@emory.mathcs.emory.edu> mana-s@ascii.co.jp (Manabu |Shimohira) writes: |> |>Hello to networld. |> |>Is there anybody who can let me understand why the dbexport is not |>suitable for database backup, or why I should avoid using dbexport |>for database backup. |> |>I thought the dbexport and dbimport is a handy method for archiving |>data with their schema. |> |>But I can find several caution to not to use dbexport for database |>backup (ex. p4-7 in I-SE ADMIN, p5-24 in GUIDE TO SQL TUTORIAL, |>p3-113 in I-OnLine ADMIN.. all for v5.0) |> |>There will be some reason not to use dbexport. I just want to know |why. | |I didn't email this as I'm sure there is some general interest in the |topic. | |The answer has several parts. First, and I think most important, is |that logs cannot be applied to a database restored via dbimport. So your |backup is a static picture of the database at a particular moment in |time. |If it is sufficient to restore your system to that point only, then |dbexport may be an appropriate choice for backup for you. However, the |secondf part is that dbexport takes a long time and locks the database |while it does its work. This means that you cannot access any data |until the export is complete. Again, if this is acceptable for your |application, then dbexport may be the right choice. If you are using |OnLine, you probably want to minimize downtime, so the OnLine backup |utilities will be more useful, since the allow on-line archiving as well |as full restoration from logs. If you are using SE, then you would use a |Unix backup utility. |Again, if you are not using a log (or don't need to recover xactions |from the time of the last backup to the time of the crash), then |dbexport may be ok. Bear in mind that it will take longer than a dd (for |example) and it will take longer to restore the database, should you need |to (again, compared to dd or equivalent). When you load the database from the dbimport hasn't the extent information been lost?... --- ~ WinQwk 2.0b#480 ~ Failed gymnast: A flip flop -- Executive Network Information System (914) 667-4567 International ILink Host