kamal-github

package collections

type Item[T any] struct {
	Item     T
	Priority int
	Index    int
}

type PriorityQueue[T any] []*Item[T]

kamal-github

import 'dart:async';

Future<void> printOrderMessage() async {
  print('printOrderMessage: Awaiting user order... fetches and returns Future<void>');
  var order = await fetchUserOrder();
  print('This and following execute only after Future is complete');
  print('Your order is: $order');
}

Future<String> fetchUserOrder() {

kamal-github

Understand error on materized view refresh concurrently.

ERROR:  cannot refresh materialized view "public.mvw_prod" concurrently
HINT:  Create a unique index with no WHERE clause on one or more columns of the materialized view.

Works

create materialized view mvw_prod as select productid, productname, supplierid from products join categories using(categoryid) where productid>5;

kamal-github

Docker file best practices

1. order instruction by least to most frequent changing content
2. Avoid COPY . (Copy only what is needed if possible)
3. Don’t use latest tag, add a specific version
4. Multi stage build -
   1. DRY
   2. small image size
   3. Build different image for test/run/lint from base buiilt image

kamal-github

Check current acticity or running query

select pid, query from pg_stat_activity where state='active';

To Cancel

select pg_cancel_backend();

kamal-github

// https://play.golang.org/p/7oTksbq9ioW


package main

import (
	"fmt"
)

func main() {

kamal-github

package main
 
import (
	"fmt"
	"log"
	"net/http"
	"net/http/pprof"
)
// HTTP request handler
func handler(w http.ResponseWriter, r *http.Request) {

kamal-github

package main

import (
	"fmt"
	"runtime"
	"sync"
)

func main() {
	// can be a input stream such as CSV/Network/File.

kamal-github

package main

import (
	"fmt"
	"time"
)

// Simpler version for Or
func OrVer2(ch ...chan struct{}) <-chan struct{} {
	switch len(ch) {

kamal-github

const (
    // When reconnecting to the server after connection failure
    reconnectDelay = 5 * time.Second
)

// Client holds necessery information for rabbitMQ
type Client struct {
    pushQueue     string
    logger        zerolog.Logger
    connection    *amqp.Connection