Re: Unicode database + JDBC driver performance
От | Jan Ploski |
---|---|
Тема | Re: Unicode database + JDBC driver performance |
Дата | |
Msg-id | 13799530.1040519800960.JavaMail.jpl@remotejava обсуждение исходный текст |
Ответ на | Unicode database + JDBC driver performance (Jan Ploski <jpljpl@gmx.de>) |
Список | pgsql-general |
On Sat, Dec 21, 2002 at 03:33:57PM -0500, Tom Lane wrote: > If no translation is happening then I can't see a reason for any > difference at all, given what you were doing. > > I can imagine speed differences for operations that actually interpret > the character data --- for example, sorting on a text column --- but > AFAICT you weren't doing anything like that. > > It'd be worth checking first to see whether the extra time is really > being spent in the backend, client, or both. Hello, Here are the results of the more detailed benchmarks. Legend: the left column is "utime", right column is "stime" (both in jiffies) according to "cat /proc/<pid>/stat" output for the 'postgres' process created by establishing the database connection. For the client, I used the Unix 'time' command (and assumed 1 jiffie == 1/100s). In short, we can see that the backend's performance is somewhat worse for the Unicode database in the INSERT benchmark. The client's (driver's) performance is much worse for Unicode in this same benchmark. In the SELECT benchmark, the backend performance does not vary between UNICODE and LATIN1 (nice!). The difference in client's performance is even bigger than in the INSERT benchmark, though. It looks like the driver needs some profiling to find out the reason. Thanks for your assistance. -JPL INSERT benchmark backend LATIN1 UNICODE 351 102 480 134 370 112 476 164 376 126 496 178 359 125 498 126 ------- ------- 364 116 487 150 33% 29% worse client LATIN1 UNICODE 234 45 418 56 224 56 441 48 241 43 430 49 222 41 439 34 ------- ------- 230 46 432 47 87% 2% worse SELECT benchmark backend LATIN1 UNICODE 70 9 74 15 74 19 84 14 84 12 71 11 71 13 74 14 ----- ----- 75 13 76 14 about the same client LATIN1 UNICODE 217 22 529 14 217 18 544 25 217 26 534 14 219 21 542 17 ------- ------- 218 22 537 18 146% worse
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