Loma  Baumbach

Loma Baumbach

1597373700

Columnar Stores — When/How/Why?

Long ago data storage was simple — heapfiles and b-trees and that’s it. Today the options are overwhelming — ORC, Parquet, Avro on HDFS or S3 or a RDBMS solution like Postgresql, MariaDB, or commercial ones like Oracle and DB2. Even within RDBMS engines and Cloud services there are many options!

This guide is a “random walk” into the broad realm of storage.


Sample DataSet

I pulled the Chicago Public workers salary info. Did you know public salaries are published w/ the **REAL **names of each person? Look up your favorite police officer or commissioner’s salary for fun (it won’t include overtime, perks nor bribes, unfortunately).

Image for post

I added a few fake people — Foo & Bar families. Otherwise its real data.

Column Oriented vs Row Oriented

First the basic storage mechanics of data. Row and column orientation.

**Row oriented **stores each individual record together, Doug Foo’s full record then Jane Foo’s, and so on in sequence.

[Doug,Foo,Foostack,Programmer,M,120000] [Jane, Foo,Foostack,Programmer,F,110000] [Doug,Bar,…]…

**Column **or **_columnar _**stores all column data together — so all First Names (Doug,Jane, etc), then all the Last Names, Titles, … , finally all Salaries.

[Doug,Jane,Doug,Jane,…][Foo,Foo,Bar,Bar…][Programmer,Programmer…]…[M,F,M,F…][120000,110000,100000,130000…]…

Data is generally read off disk by blocks of KB (or MB/GB), so a single read for 1 record brings in a lot more than what you may want.

Typical Block Sizes[*1]:

  • HDFS: 128MB (Chunks)
  • Google FS: 64MB (Chunks)
  • Amazon AWS S3: 128KB
  • Oracle Data Warehouse: 32KB
  • Postgres DB: 8KB
  • Linux and Windows Filesystems: 4KB

Salary records are pretty small ~ 50chars (<50 bytes). An 8KB block with metadata could easily store 100+ row oriented records [8192 / 50 = 163]. So a single read of the block containing “Doug Foo”’s record includes a lot more.

For **columnar **block reads — the read varies on column size. For example with 8KB blocks:

  • First Name may avg 10 bytes, meaning upwards of ~800 names.
  • Salary could fit in a 32bit Int (4bytes) yielding ~2000 entries!
  • Gender is M/F/? — could be stored as 1 byte or even a half nibble ~ 8000!

This will be important to keep in mind as we do more analysis later.

#big-data-analytics #columnar-databases #storage-containers #big-data #database

What is GEEK

Buddha Community

Columnar Stores — When/How/Why?
Kole  Haag

Kole Haag

1602403200

What is NoSQL and How is it Utilized?

Posted on September 25, 2020 by Dean Conally | Updated: October 8, 2020

Category: Tutorials | Tags: CassandraColumnsDatabaseDatabase ManagementDatabase StructureDB2Document StoresDynamic SchemaExtensible Record StoresGraph StoresJSONKey-ValueMSSQLMulti-RowMySQLNodeNode Relationship NodeNon-Relational DatabasesNoSQLNoSQL ModelQueryRowsScalabilitySchema FreeSQLStoresTablesWide-Column

Reading Time: 5 minutes

What is NoSQL?

A NoSQL or a NoSQL Database is a term used when referring to a “non SQL” or “not only SQL” database. NoSQL databases store data in a different format than a traditional relational database management systems. This is why NoSQL is often associated with the term “non-relational” database. Simply put, NoSQL databases are modern databases with high flexibility, blazing performance, and built for scalability. These databases are used when you require low latency and high extensibility while working with large data structures. The versatility of NoSQL is due to the nature of as being unrestricted in comparison to relational databases models such as MySQL or DB2.

SQL vs. NoSQL Comparison

There are multiple differences between SQL and NoSQL database types. In the table below, we will compare some of the most critical variations.

#tutorials #cassandra #columns #database #database management #database structure #db2 #document stores #dynamic schema #extensible record stores #graph stores #json #key-value #mssql #multi-row #mysql #node #node relationship node #non-relational databases #nosql #nosql model #query #rows #scalability #schema free #sql #stores #tables #wide-column

i-Verve Inc

i-Verve Inc

1621594876

How to start an online grocery store | Setting up Online Grocery Business in 2021

Start An Online Grocery Store

Despite the Covid-19 threat to the world and economy of every country, Online Grocery Market has recorded a 3X increase since 2019 till now.

“About 1-4th online shoppers are already shopping groceries on the internet in developed countries and 55% are willing to in near future. – Nielson study”

The new store these days are digital stores, Web stores, and Mobile applications where 70% of the customers reach and buy every day.

Take your store where the customers are to generate more revenue by developing e-commerce grocery store/application and Supermarket online store and mobile application.

Online grocery shopping sales in the United States from 2018 to 2023(in billion U.S. dollars)

“As per Statista, The U.S. online grocery market was estimated to generate sales worth about 28.68 billion U.S. dollars in 2019, with sales forecast to reach 59.5 billion U.S. dollars by 2023.”

Online store and mobile applications are helping small grocery business owners reach 70% more customers and generate unbelievable but real 48% more revenue other than the existing one. Check out a few of the businesses listed below:

  • Dry fruit sellers
  • Vegetables and organic vegetable sellers
  • Fruits and Organic Fruit sellers
  • Bakery product seller
  • Meat seller
  • Milk and Milk product seller
  • Mega Grocery store owner (All in one)

Want to start an online grocery store? – Here’s what you should know

If you dream of owning your own online store regardless are you setting up a small business for the first time or you’ve been in the game a long time, this guide will help you learn how to start an online store.

Online selling, better known as e-commerce, has truly hit its pace. Fortunately, getting started is easier than you might think provided you have basic information about the business (which we will cover here) and you have a team of ecommerce website store solution experts to get the things implemented.

Accenture estimates, by the end of 2020, the ecommerce industry will get 13.5% of the revenue share. What does it mean for online store owners? It means that out of every 7 dollars spent on retail consumption: eCommerce will get about 1 dollar.

This article was originally published - How to start an online grocery store?

#start an online grocery store, #steps to opening a successful online business #steps to open online store #create your own grocery store #ecommerce store development

Loma  Baumbach

Loma Baumbach

1597373700

Columnar Stores — When/How/Why?

Long ago data storage was simple — heapfiles and b-trees and that’s it. Today the options are overwhelming — ORC, Parquet, Avro on HDFS or S3 or a RDBMS solution like Postgresql, MariaDB, or commercial ones like Oracle and DB2. Even within RDBMS engines and Cloud services there are many options!

This guide is a “random walk” into the broad realm of storage.


Sample DataSet

I pulled the Chicago Public workers salary info. Did you know public salaries are published w/ the **REAL **names of each person? Look up your favorite police officer or commissioner’s salary for fun (it won’t include overtime, perks nor bribes, unfortunately).

Image for post

I added a few fake people — Foo & Bar families. Otherwise its real data.

Column Oriented vs Row Oriented

First the basic storage mechanics of data. Row and column orientation.

**Row oriented **stores each individual record together, Doug Foo’s full record then Jane Foo’s, and so on in sequence.

[Doug,Foo,Foostack,Programmer,M,120000] [Jane, Foo,Foostack,Programmer,F,110000] [Doug,Bar,…]…

**Column **or **_columnar _**stores all column data together — so all First Names (Doug,Jane, etc), then all the Last Names, Titles, … , finally all Salaries.

[Doug,Jane,Doug,Jane,…][Foo,Foo,Bar,Bar…][Programmer,Programmer…]…[M,F,M,F…][120000,110000,100000,130000…]…

Data is generally read off disk by blocks of KB (or MB/GB), so a single read for 1 record brings in a lot more than what you may want.

Typical Block Sizes[*1]:

  • HDFS: 128MB (Chunks)
  • Google FS: 64MB (Chunks)
  • Amazon AWS S3: 128KB
  • Oracle Data Warehouse: 32KB
  • Postgres DB: 8KB
  • Linux and Windows Filesystems: 4KB

Salary records are pretty small ~ 50chars (<50 bytes). An 8KB block with metadata could easily store 100+ row oriented records [8192 / 50 = 163]. So a single read of the block containing “Doug Foo”’s record includes a lot more.

For **columnar **block reads — the read varies on column size. For example with 8KB blocks:

  • First Name may avg 10 bytes, meaning upwards of ~800 names.
  • Salary could fit in a 32bit Int (4bytes) yielding ~2000 entries!
  • Gender is M/F/? — could be stored as 1 byte or even a half nibble ~ 8000!

This will be important to keep in mind as we do more analysis later.

#big-data-analytics #columnar-databases #storage-containers #big-data #database

vaxxy allen

1601363503

Prestashop Store Locator and Pickup | In-Store Pickup Addon | Knowband

Knowband provides PrestaShop store locator and pickup module which shows a store locator on the site. The online sellers can allow the users to check the store availability. The users can check the nearby store and also pick up the product. The PrestaShop store locator and pickup extension permits the store owner to offer a pickup feature to the customers. The online sellers can show the store information on the Google map. The customers can also check the driving instructions. 
The PrestaShop Store Locator and Pickup module is fully customizable and the store owner can displays the total distance, contact number and store timing also. The PrestaShop in-store pickup module offers a user-friendly dashboard. The store owner can easily configure this PrestaShop module. PrestaShop store locator and pickup extension provides multi-lingual compatibility.
 
**Benefits offered by this PrestaShop store locator and pickup module: **

  • With the help of Prestashop store locator and pickup, store owner can provide in-store pickup facility to the customers.
  • The store owner can enable or disable the PrestaShop store pickup extension just by a button press.
  • The store owner can easily activate the store locator and pickup functionality.
  • The store owner can generate Google map API key simply.
  • The PrestaShop store locator and pickup module allow the store owner to adjust an image as Google map marker and the zoom level of the map.
  • The online sellers can set the distance units in Kilometers or Miles.
  • The PrestaShop Store Locator module permits the store owner to choose the stores for displaying in the Google map. The store owner can also choose the default store.
  • The store owner can display the contact details of the store.
  • PrestaShop Store Locator and pickup module allows displaying a “Get Directions” link. The users can press on this link and see the directions for visiting the shop.
  • The Prestashop store pickup module permits displaying website link on Google maps store location. Customers can also see the website URL with other store information.
  • The store owner can displays store picture in the stores list present on store locator block. The Prestashop Store locator module can enable or disable the settings for the store picture.

Important Links:
Admin Demo
Front Demo
User Manual

#prestashop #store #locator #knowband #module #addon

Tamia  Walter

Tamia Walter

1594046580

How I Broke My App Store Connect Listing

As of right now, I haven’t been able to push a critical update to my app for more than three days. I’ve had to watch my old build languish on the App Store, despite my frenzied clicks trying to update it or change it.

It all started when I uploaded my initial app, written in Flutter. I submitted three screenshots for iPhone, and three for iPad. Unfortunately, I hit the upload button before the screenshots were complete. This resulted in this weird outcome.

What’s wrong with this picture?

You can see for yourself here.

You might think, what’s wrong with that? The issue is that at a minimum, each app _must _have three screenshots per device in order for submission. It’s logically impossible to have an app on the App Store with only two screenshots per platform.

Reviewing my app metadata in App Store Connect for the app, under iPad, I can see these for my screenshots:

What’s with the third one?

Because the app is accepted and ‘Ready for Sale’, I can’t change the metadata, or upload new screenshots, or literally anything. Trying to submit 1.1 of my app results in this happy message.

#app-store #app-store-connect #ios-development #apple-development #developer