ycku

                                                               QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=10438.81..10438.82 rows=1 width=8) (actual time=80.819..84.547 rows=1 loops=1)
   ->  Gather  (cost=5774.06..10438.80 rows=1 width=0) (actual time=52.857..83.197 rows=27183 loops=1)
         Workers Planned: 1
         Workers Launched: 1
         ->  Parallel Hash Anti Join  (cost=4774.06..9438.70 rows=1 width=0) (actual time=46.786..67.737 rows=13592 loops=2)
               Hash Cond: (s.key = t.key)
               ->  Parallel Seq Scan on s  (cost=0.00..2843.47 rows=117647 width=4) (actual time=0.004..8.666 rows=100000 loops=2)
               ->  Parallel Hash  (cost=2843.47..2843.47 rows=117647 width=4) (actual time=22.881..22.882 rows=100000 loops=2)

ycku

-- SELECT sqlcheck('select * from not_exist_table');
-- 42P01: undefined_table
-- SELECT sqlcheck('select * from not_exist_table wrong_syntax');
-- 42601: syntax_error
-- 語法檢查會優先於物件檢查

CREATE OR REPLACE FUNCTION sqlcheck(query text) RETURNS text AS
$$
DECLARE
	sql text;

ycku

• grep CODE_ID and extract the VALUE

echo '{"CODE_ID":"12345678","CODE_NOTE":"abcdefg","CODE_ID":"87654321"}' | grep -oP '"CODE_ID":"\K.*?(?=")'

12345678
87654321

• https://askubuntu.com/questions/1167287/parse-json-with-default-bash-only

ycku

Demo patroni on docker

• 可以自行建立 patroni 實驗環境
• 以 Failover 作為環境測試情境

1. Docker Environment

• 使用 Docker playground: https://labs.play-with-docker.com/
• 使用 DockerHub 帳號登入後, ADD NEW INSTANCE, 可以使用 4 小時

ycku

# pip install boto3

import boto3
from datetime import datetime, timedelta

# 初始化 Cost Explorer 客戶端
client = boto3.client('ce')

# 設定日期範圍
end_date = datetime.now().strftime('%Y-%m-%d')

ycku

-- Excel NORM.DIST(x, mean, stddev. FALSE)
SELECT (1 / (stddev * sqrt(2 * pi()))) * exp(-1 * power(x - mean, 2) / (2 * power(stddev, 2))) AS pdf
FROM (
    SELECT 5.5 AS x, 5.0 AS mean, 1.0 AS stddev
) t;

-- Excel NORM.DIST(x, mean, stddev. TRUE)
SELECT 0.5 * (1 + erf((x - mean) / (stddev * sqrt(2)))) AS cdf
FROM (
    SELECT 5.5 AS x, 5.0 AS mean, 1.0 AS stddev

ycku

export RDSHOST="rds.hostname"
export SECRETID="secret-id"
export SECRETSTRING=$(aws secretsmanager get-secret-value --secret-id "${SECRETID}" --query SecretString --output text)
export PGHOST="${RDSHOST}"
export PGUSER=$(echo "${SECRETSTRING}" | jq -r '.username')
export PGPASSWORD=$(echo "${SECRETSTRING}" | jq -r '.password')