vlsi

This is a result of running https://github.com/vlsi/microbenches/commit/34c694dcb48acce0a37334631747fb371d80c80f

1) Best result for testSingle is for java7u55+catch(AIOOBE), however java7's results are not stable

2) java 7 results are very unstable:
For isntance:
# Warmup Iteration   1: 548,557 ns/op
...
# Warmup Iteration   6: 102,104 ns/op
...

vlsi

This is a result logs of running

mvn release:clean release:prepare
mvn release:perform

in https://github.com/vlsi/pgjdbc/commits/sample_release branch

vlsi

/*
 * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *

vlsi

Vladimir Sitnikov is currently working on performance and scalability of NetCracker OSS.
Telecommunication companies world wide use NetCracker OSS for enterprise and network automation.
Vladimir is keen on Java and database performance: Oracle, PostgreSQL. He’s one of the committers
in the PostgreSQL JDBC driver project, and architect of many performance improvements.

Abstract.

Common Java wisdom is to use PreparedStatements and Batch DML in order to achieve top performance.
It turns out one cannot just blindly follow the best practices. In order to get high throughput, you need
to understand the specifics of the database in question, and the content of the data.

vlsi

drop table vlsi;

create table vlsi(pk int4, type numeric, vc varchar(500), num numeric);

insert into vlsi(pk, type,vc,num) select s.x, round(x/1000), md5('||x)||md5('||x+1)||md5(''||x+2), mod(x, 1000)
  from generate_series(1,1000000) as s(x);

-- Several values exceeed 128 substr, so they require "table access"
insert into vlsi(pk, type,vc,num) select s.x+1000000, round(x/1000), lpad('a', 128, 'a')||'zxc'||s.x||'v', mod(x, 1000)
  from generate_series(1,10) as s(x);

vlsi

According to the measurements, replaceRange + append works faster than setText except for the case when text is fully replaced. In 100% replace case setText is on par with replaceRange + append (the results are within error bounds).

For small appends there's a win in terms of response time and memory allocation.

# JMH 1.12 (released 309 days ago, please consider updating!)
# VM version: JDK 1.8.0_102, VM 25.102-b14
# VM invoker: /Library/Java/JavaVirtualMachines/jdk1.8.0_102.jdk/Contents/Home/jre/bin/java

vlsi

,,,,,,,,,,,,,,,,,,,,,,,
,,,,,,,,,,,,,,,,,,,,,,,
,,,,,,,,,,,,,,,,,,,,,,,
,,,,,,,,,,,,,,,,,,,,,,,
,,,,,,,,,,,,,,",,",,",,",,,,,,,
,,,,,,,,,,,,,,,,,,,,,,,
,,,,,,,,,,,,,,,,,,,,,,,
,,,,,,,,,,,,,,,,,,,,,,,
,,,,,,,,,,,,",,,,,,,,,,,
,,,,,,,,,,,,,,,,,,,,,,,

vlsi

#
# A fatal error has been detected by the Java Runtime Environment:
#
#  Internal Error (/Users/vladimirsitnikov/Documents/work/shenandoah/src/hotspot/share/opto/node.cpp:177), pid=57596, tid=27907
#  assert(_refresh_tick < 2*100000) failed: DU iteration must converge quickly
#
# JRE version: OpenJDK Runtime Environment (10.0) (fastdebug build 10-internal+0-adhoc.vladimirsitnikov.shenandoah)
# Java VM: OpenJDK 64-Bit Server VM (fastdebug 10-internal+0-adhoc.vladimirsitnikov.shenandoah, mixed mode, tiered, compressed oops, g1 gc, bsd-amd64)
# No core dump will be written. Core dumps have been disabled. To enable core dumping, try "ulimit -c unlimited" before starting Java again
#

vlsi

Current JMeter's JMX files are not human-readable, and it is hard to review "diff" between two versions of a script.

I suggest adding a human-readable comment to the start of the file, so the diff between scripts can be easier to understand:

<?xml version="1.0" encoding="UTF-8"?>
<!--
Test plan:
   Thread group (146 threads, 1:00:00 duration)
      login (http sampler /login)

vlsi

Keybase proof

I hereby claim:

• I am vlsi on github.
• I am vlsi (https://keybase.io/vlsi) on keybase.
• I have a public key ASC2sRZGT4IKWFFWjBEznXZ8DHXjdgWnotEDW-x6_eLlYAo

To claim this, I am signing this object: