On 18.09.2012 12:08, Suat Gönül wrote:
Hi David,

I had inserted 860K items to the database in total. There was an index over the revision field. Here are the elapsed times for the whole process:

Insertion 1 by 1 with PreparedStatement: ~8121 s
Insertion 1000 by 1000 with Statement: ~886 s
Insertion 1000 by 1000 with PreparedStament: ~532 s

If possible with the app logic, it would speed things up to first add the index *after* the inserts are done. Another approach is to use the SYSCS_UTIL.SYSCS_IMPORT_* stored procedures if data is available on a file format.

Dag


Best,
Suat


On Mon, Sep 17, 2012 at 10:20 PM, david myers <david.myers.scibearspace@gmail.com> wrote:
Suat

If you are doing insertions that use the exact same statement that many times in succession you should see a performance improvement using a prepared statement.

Also the prepared statement will negate the need to worry about escaping any other 'special characters' as part of the idea is that the prepared statement will deal with them at the level of the DBMS. Rather than forcing you to deal with it in your code. The same is also true with Callable statements.

That said I would be interested to see how much of a difference it makes using a normal or prepared statement, mainly to see where the break point is in such things.

David





On 13/09/12 13:14, Suat Gonul wrote:
On 09/13/2012 01:54 PM, Knut Anders Hatlen wrote:
Suat Gonul <suatgonul@gmail.com> writes:

Hi Knut,

It seems that is the problem, thanks. But, then I think I should escape
special characters contained the values. Is there standard procedure for
this? Is there a list of of special characters? What do you suggest?
I'd suggest that you use prepared statements with parameter markers

INSERT INTO t (id, revision) VALUES (?, 1)

and use ps.setString(1, "string value") to set the value. Then you don't
need to worry about special characters in the string.

If you want to specify the string literally in your SQL statement, only
the single-quote character is a special character, as far as I know, and
it can be escaped with an extra single-quote character. For example, to
insert the string «It's safer with PreparedStatement», you would have to
do something like this:

INSERT INTO t (id, revision) VALUES ('It''s safer with PreparedStatement', 1)

Thank you very much. Escaping the ' character with another ' has solved
my problem.

Indeed I am doing a bulk insertion operation (1000 insertion at a time
(Values > 1000 causes stackoverflow exception)). So I prepare the query
in advance and execute it in one step. In total, I have ~1M records.
However, I could not decide on which one would be more efficient. So,
I'm trying both options now.

Thanks again,
Best,
Suat