[thelist] Oracle Sequences: was MySQL Tables for weblog

rudy r937 at interlog.com
Sun Mar 17 09:38:01 CST 2002

this is a bit offtopic, so there's a tip...

> I hope this means you wrote your own SQL,
> and didn't rely on an Oracle Sequence?

hi jane

no, we used ordinary sequences

> You did know that if you export and re-import your
> Oracle DB (so as to compress and tidy up)...

like a defrag?  is that even necessary?

export/import sure would be the easiest, assuming you can take the database

>   ... all your sequences get re-set?
> We made that mistake: once and never again!

i'm guessing your sequences started over again with low numbers, and then
when you started inserting records, there were collisions with existing

you'd have to allow for this by also resetting the sequence back up to
where it was...

if you can't do that, then maybe change the key sequences

for example, if your tables contain sequence-assigned keys between 1 and
29000 (approximate range of evolt's keys) and suddenly the sequences start
over at 1, then just change the insert statement to add 100000 to the
sequence number before using it as a new key...

there's only one insert statement in your application, right?  i mean, one
per table?

<tip type="information architecture design">
  let's say you're designing web forms that will be used in applications
that interact with a backend database, so these forms can get pretty
complicated, what with all the different pieces of information involved,
and you notice that sometimes the form has several groups of similar
fields, and sometimes these similar fields are in a separate form that the
user would keep submitting until all the groups are entered, and then come
back to the main form...
  did you know that it makes no difference to the database which way you
design your forms?  (it's a one-to-many table relationship)
  it could, however, make a huge difference in the amount of development
required --the application programming, the logic that interacts with the
database -- because there's an easy way and there's a hard way to program
that interaction
  it depends on whether the user is allowed to get up and leave the
computer for an indeterminate time after entering only some of the groups
of detailed data before going back to the main form
  what's the tip?
  talk to your developers -- early


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