Database: custom_columns: What is 'normalized'?

ownedbycats · 12-18-2022, 02:57 AM

In the custom_columns table of metadata.db is a bool column normalized. What is this for?

kovidgoyal · 12-18-2022, 03:27 AM

normalized is for columns that store many-one or many-many values. Think of tags vs titles.

ownedbycats · 12-18-2022, 02:54 PM

That makes sense. Thanks

chaley · 12-18-2022, 05:46 PM

If you want a more formal discussion of normalization see (for example) https://en.wikipedia.org/wiki/Third_normal_form and https://learn.microsoft.com/en-us/of...on-description

theducks · 12-18-2022, 09:03 PM

Many years ago Borland's Paradox DOS had an example
An Airline ticket with multiple stops.

There was the Passenger Table with all the info (tel, charge method...)
There was the Ticket (parent) issued to Passenger

There was the Hop table that had an entry for each hop Linked to the ticket. there was no limit on how many hops
There was a schedule table that detailed Flights to flesh out the hop details
All the tables were really narrow (few columns)

12-18-2022, 02:57 AM	#1
ownedbycats Custom User Title Posts: 11,364 Karma: 79528341 Join Date: Oct 2018 Location: Canada Device: Kobo Libra H2O, formerly Aura HD	Database: custom_columns: What is 'normalized'? In the custom_columns table of metadata.db is a bool column normalized. What is this for?

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12-18-2022, 03:27 AM	#2
kovidgoyal creator of calibre Posts: 45,616 Karma: 28549044 Join Date: Oct 2006 Location: Mumbai, India Device: Various	normalized is for columns that store many-one or many-many values. Think of tags vs titles.

12-18-2022, 02:54 PM	#3
ownedbycats Custom User Title Posts: 11,364 Karma: 79528341 Join Date: Oct 2018 Location: Canada Device: Kobo Libra H2O, formerly Aura HD	That makes sense. Thanks

12-18-2022, 05:46 PM	#4
chaley Grand Sorcerer Posts: 12,525 Karma: 8065948 Join Date: Jan 2010 Location: Notts, England Device: Kobo Libra 2	If you want a more formal discussion of normalization see (for example) https://en.wikipedia.org/wiki/Third_normal_form and https://learn.microsoft.com/en-us/of...on-description

12-18-2022, 09:03 PM	#5
theducks Well trained by Cats Posts: 31,271 Karma: 61916422 Join Date: Aug 2009 Location: The Central Coast of California Device: Kobo Libra2,Kobo Aura2v1, K4NT(Fixed: New Bat.), Galaxy Tab A	Many years ago Borland's Paradox DOS had an example An Airline ticket with multiple stops. There was the Passenger Table with all the info (tel, charge method...) There was the Ticket (parent) issued to Passenger There was the Hop table that had an entry for each hop Linked to the ticket. there was no limit on how many hops There was a schedule table that detailed Flights to flesh out the hop details All the tables were really narrow (few columns)

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