Sadeq Dousti msdousti

src/backend/access/nbtree/README

Btree Indexing

This directory contains a correct implementation of Lehman and Yao's high-concurrency B-tree management algorithm (P. Lehman and S. Yao, Efficient Locking for Concurrent Operations on B-Trees, ACM Transactions on Database Systems, Vol 6, No. 4, December 1981, pp 650-670). We also use a simplified version of the deletion logic described in Lanin and Shasha (V. Lanin and D. Shasha, A Symmetric Concurrent B-Tree Algorithm, Proceedings of 1986 Fall Joint Computer Conference, pp 380-389).

	import matplotlib.pyplot as plt
	import numpy as np

	# Provided data
	data = [
	5, 18, 32, 40, 54, 68, 80, 100, 110, 119, 125, 136, 144, 149, 154, 160, 165,
	171, 178, 182, 189, 195, 202, 211, 216, 222, 227, 234, 239, 245, 250, 256,
	261, 268, 273, 278, 283, 289, 295, 301, 307, 314, 320, 325, 332, 339, 346,
	352, 358, 364, 370, 376, 383, 389, 396, 402, 409, 415, 422, 429, 436, 443,
	450, 458, 466, 473, 481, 489, 496, 503, 511, 519, 527, 536, 545, 555, 564,

	* explain.h all over the place
	* saving query plan before executing it (execMain.c)
	* performance?
	* GUC to enable?
	* TAP tests

	* pg_stat_session --> "One row per client backend"
	--> should the name indicate this, e.g. pg_stat_client_backend

	* Information is scattered between pg_stat_activity and this view, requiring join
	* Example: client_addr, application_name, usename


	* Can we define this outside the function pg_stat_get_session?
	#define PG_STAT_GET_SESSION_COLS 9

	create table t (
	id bigint generated always as identity not null,
	created_at timestamptz not null)
	partition by range (created_at);

	create index t__id__created_at__idx
	on t(id, created_at);


	-- partition for next month

	import sys

	def join_paragraph_lines(input_text):
	paragraphs = input_text.strip().split('\n\n')

	joined_paragraphs = []

	for paragraph in paragraphs:
	lines = paragraph.splitlines()
	sep = ''

	#!/usr/bin/env bash
	set -euo pipefail

	# Define default commands
	COMPILE_CMD="./mvnw compile"
	PACKAGE_CMD="./mvnw package -DskipTests -pl logbook-servlet -am"
	VERIFY_CMD="./mvnw verify -B"
	INSTALL_CMD="./mvnw install -DskipTests -Djacoco.skip=true"

	# Flags to track selected options

	create table my_outbox
	(
	id serial,
	data jsonb not null,
	created timestamp with time zone default now() not null,
	primary key (id, created)
	);

	insert into my_outbox (data, created)
	values ('{"a": 1}'::jsonb, default),

	create table test
	as
	select id, random() > 0.5 as to_be
	from generate_series(1, 10000000) as id;

	CREATE INDEX IF NOT EXISTS idx_1
	ON test (id)
	WHERE to_be = true;

	CREATE INDEX IF NOT EXISTS idx_2

	#!/bin/bash

	users=("cantony" "hadmohammadi" "helseoudy" "mmorsy" "mtaufikakbar" "pebermann" "rogupta" "sdousti" "tschlage" "yzykau")
	token=`ztoken`

	for user in ${users[*]}; do
	has_role=$(curl -sH "Authorization: Bearer $token" https://users.auth.zalando.com/api/employees/$user/groups \| jq '.[] \| select(.dn \| contains("24x7 Emergency,ou=Retail Operations")) \| length > 0')
	echo "$user: $has_role"
	done

Sadeq Dousti msdousti

Btree Indexing

The basic Lehman & Yao Algorithm