Re: Inconsistent performance with LIKE and bind variable on long-lived connection

> On 10 Jun 2017, at 5:37, Steven Grimm <sgrimm(at)thesegovia(dot)com> wrote:

[…]

I notice that you're declaring your ResultSet variable inside the loop, which means that you create and destroy it frequently. I've been told that this is a pattern that the GC has trouble keeping up with (although that was around the Java 5 era), so you might be seeing the effects of memory churn in your client instead of in the database.

I modified your function to not do that anymore, does that make a difference?

Note; the long variables are scalar instead of objects. I don't think they need the same treatment, but it can't hurt.

> private static void logTime(String name, PreparedStatement stmt) throws SQLException {
> StringBuilder out = new StringBuilder(String.format("%-22s", name));
> ResultSet rs;
> long startTime, endTime;
>
> for (int i = 0; i< 20; i++) {
> startTime = System.currentTimeMillis();
> rs = stmt.executeQuery();
> while (rs.next()) {
> rs.getString(1);
> }
> endTime = System.currentTimeMillis();
> rs.close();
>
> out.append(String.format(" %3d", endTime - startTime));
> }
>
> stmt.close();
>
> System.out.println(out);
> }

Alban Hertroys
--
If you can't see the forest for the trees,
cut the trees and you'll find there is no forest.