valyala

Optimizing postgresql table for more than 100K inserts per second

• Create UNLOGGED table. This reduces the amount of data written to persistent storage by up to 2x.
• Set WITH (autovacuum_enabled=false) on the table. This saves CPU time and IO bandwidth on useless vacuuming of the table (since we never DELETE or UPDATE the table).
• Insert rows with COPY FROM STDIN. This is the fastest possible approach to insert rows into table.
• Minimize the number of indexes in the table, since they slow down inserts. Usually an index on time timestamp with time zone is enough.
• Add synchronous_commit = off to postgresql.conf.
• Use table inheritance for fast removal of old data:

tkrajina

package main

import (
	"fmt"
	"reflect"
)

type Aaa struct {
	a string
}

tasdikrahman

A Typical directory structure for running tests using unittest

Ref : stackoverflow

The best solution in my opinion is to use the unittest [command line interface][1] which will add the directory to the sys.path so you don't have to (done in the TestLoader class).

For example for a directory structure like this:

new_project

├── antigravity.py

jarvisschultz

cmake_minimum_required(VERSION 2.8.3)
project(pycpp_test)

find_package(catkin REQUIRED COMPONENTS
  roscpp
)

find_package(PythonLibs 3.4 EXACT)

catkin_package()

cpq

Why stack grows down

Any running process has several memory regions: code, read-only data, read-write data, et cetera. Some regions, such as code and read-only data, are static and do not change over time. Other regions are dynamic: they can expand and shrink. Usually there are two such regions: dynamic read-write data region, called heap, and a region called stack. Heap holds dynamic memory allocations, and stack is mostly used for keeping function frames.

Both stack and heap can grow. An OS doesn't know in advance whether stack or heap will be used predominantly. Therefore, an OS must layout these two memory regions in a way to guarantee maximum space for both. And here is the solution:

1. Layout static memory regions at the edges of process's virtual memory
2. Put heap and stack on edges too, and let them grow towards each other: one grows up, one grows down

eberle1080

// Assumption: you have a variable named "pyobj" which is
// a pointer to an instance of PyUnicodeObject.

PyObject* temp = PyUnicode_AsASCIIString(pyobj);
if (NULL == temp) {
    // Means the string can't be converted to ASCII, the codec failed
    printf("Oh noes\n");
    return;
}

scaryguy

-- Firstly, remove PRIMARY KEY attribute of former PRIMARY KEY
ALTER TABLE <table_name> DROP CONSTRAINT <table_name>_pkey;

-- Then change column name of  your PRIMARY KEY and PRIMARY KEY candidates properly.
ALTER TABLE <table_name> RENAME COLUMN <primary_key_candidate> TO id;

peterhellberg

package main

import (
  "fmt"
	"runtime"
)

func MaxParallelism() int {
	maxProcs := runtime.GOMAXPROCS(0)
	numCPU := runtime.NumCPU()

leommoore

#SOA Manifesto

In 2002, Jeff Bezos (CEO of Amazon), issued a mandate requiring all teams to expose their data and functionality through services interfaces. Jeff Bezos understood that in order for his company to be successful, he had to switch focus from creating a "perfect product" to creating a perfect platform for that product.

He mandated that:

• All teams will henceforth expose their data and functionality through service interfaces
• Teams must communicate with each other through these interfaces
• There will be no other form of interprocess communication allowed: no direct linking, no direct reads of another team's data store, no shared-memory model, no back-doors whatsoever. The only communication is via service interface calls over the network.
• It doesn't matter what [API protocol] technology you use

mandel59

// -*- coding: utf-8 -*-
// 参考: 床井研究室 - (4) シェーダの追加
// http://marina.sys.wakayama-u.ac.jp/~tokoi/?date=20120909
package main

import (
	gl "github.com/chsc/gogl/gl33"
	"github.com/jteeuwen/glfw"
	"log"
	"unsafe"