Column "Modified", 99% of my books have the same recent date in this column.

Pierre-Olivier · 11-09-2018, 09:37 AM

Hello,

I've just encountered a strange thing. I was using Calibre 3.25 (now it has been updated), and I saw that nearly all my books have the same date in the column "modified" : 3 nov 2018. I have absolutely not modified all my books this day, and I wonder how it coud have happened.

It's a real problem, because I use Calibre companion, and and when this column is modified, it downloads the new metadata, and with my huge collection of eBooks, it takes between 4 and 12 hours, depending on the device.

Can someone try to give an explanation.

Thx

jhowell · 11-09-2018, 09:46 AM

Some actions result in changing metadata for multiple books. A common one is changing the case of a tag, say from "fiction" to "Fiction". That will update all books containing that tag.

theducks · 11-09-2018, 10:59 AM

Also running Library Maintenance will affect ALL

My guess that you added a book with:

tags in common with the book that were changed BUT it had a different 'case', and Calibre updates the case of the tag
or
it was one of those with dozens of tags with the wrong case, so lots of books got hit

FWIW I use Title case for my tags and I wish Calibre would have a 'filter action' to do that one (it has Upper, Lower, Capitalize)

Pierre-Olivier · 11-09-2018, 11:22 AM

Thanks for the answer, but it's not this. I only use 19 tags, and never modified them.

theducks · 11-09-2018, 11:53 AM

Quote:

Originally Posted by Pierre-Olivier

Thanks for the answer, but it's not this. I only use 19 tags, and never modified them.

You did not import any books? The Import (read from metadata) can flip case on you. with only 19, the chances of affecting a goodly number of titles is high.

Pierre-Olivier · 11-09-2018, 12:20 PM

Of course I import regularly some eBooks.

How is it possible to avoid such global modifications.?

theducks · 11-09-2018, 12:28 PM

Quote:

Originally Posted by Pierre-Olivier

Of course I import regularly some eBooks.

How is it possible to avoid such global modifications.?

The cure is more painful than correcting the change.

But take a look at Preferences: Adding books: Adding Actions (a tab)

I have rules to filter Tags (a button):

Capitalize the tag if it matches pattern (.+)

You could choose 'your' what to do style

Modified is mostly an internal flag the the backup OPF is queued for update (also updates a CC sync if you use CC, on the next connect)

DaltonST · 11-09-2018, 12:33 PM

You can change the Last Modified Date to anything you please with the Job Spy plugin.

davidfor · 11-09-2018, 06:15 PM

Another reason for the timestamp to be changed for all books is changing custom columns. Adding or removing them will update them all. Also, changes the set of values for a "Text, but with a fixed set of permitted values" will also update everything. That's a behaviour I really don't like. But, it's easy to fix if you want to run from source.

BetterRed · 11-09-2018, 06:41 PM

For all the reasons given by other responders I ignore the Modified column entirely.

I have a Last Action Date custom column that I update whenever I do anything that I regard as significant. Because I edit in the book list it's easy to maintain.

BR

Pierre-Olivier · 11-11-2018, 01:25 PM

yen I've also thought to such a solution, but Calibre Companion use only the "last_modified" column, and it's really a pain when this app decide to download metadata of thousands of eBooks because this column has been modified for an unknown reason. None of the explanation mentioned above can explain such a behavior for my use.

DaltonST · 11-11-2018, 02:42 PM

Going forward, back up the LMD for every book en masse routinely so it can be restored in seconds so that CC does not trigger any activity. Job Spy has 56 tools; this is one of them.

capink · 05-11-2020, 01:31 AM

Quote:

Originally Posted by davidfor

Another reason for the timestamp to be changed for all books is changing custom columns. Adding or removing them will update them all. Also, changes the set of values for a "Text, but with a fixed set of permitted values" will also update everything. That's a behaviour I really don't like. But, it's easy to fix if you want to run from source.

Can someone help by pointing out what code to change to prevent this behavior, for modifying custom columns or editing tags. I have some basic python knowledge and tried to search for it myself with no success.

davidfor · 05-11-2020, 01:48 AM

Quote:

Originally Posted by capink

Can someone help by pointing out what code to change to prevent this behavior, for modifying custom columns or editing tags. I have some basic python knowledge and tried to search for it myself with no success.

You want "src\calibre\db\cache.py", line 1946. I change this from:

Code:

if changed:

to

Code:

if changed and False:

I have been doing that for a while with no ill effects.

capink · 05-11-2020, 03:24 AM

Quote:

Originally Posted by davidfor

I have been doing that for a while with no ill effects.

Thank you very much for your prompt reply. Much appreciated.

11-09-2018, 09:37 AM	#1
Pierre-Olivier Enthusiast Posts: 47 Karma: 30 Join Date: Jan 2010 Location: Dans les Landes ... Device: PocketBook Touch Lux 3	Column "Modified", 99% of my books have the same recent date in this column. Hello, I've just encountered a strange thing. I was using Calibre 3.25 (now it has been updated), and I saw that nearly all my books have the same date in the column "modified" : 3 nov 2018. I have absolutely not modified all my books this day, and I wonder how it coud have happened. It's a real problem, because I use Calibre companion, and and when this column is modified, it downloads the new metadata, and with my huge collection of eBooks, it takes between 4 and 12 hours, depending on the device. Can someone try to give an explanation. Thx

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11-09-2018, 09:46 AM	#2
jhowell Grand Sorcerer Posts: 6,496 Karma: 84420419 Join Date: Nov 2011 Location: Tampa Bay, Florida Device: Kindles	Some actions result in changing metadata for multiple books. A common one is changing the case of a tag, say from "fiction" to "Fiction". That will update all books containing that tag.

11-09-2018, 10:59 AM	#3
theducks Well trained by Cats Posts: 29,795 Karma: 54830978 Join Date: Aug 2009 Location: The Central Coast of California Device: Kobo Libra2,Kobo Aura2v1, K4NT(Fixed: New Bat.), Galaxy Tab A	Also running Library Maintenance will affect ALL My guess that you added a book with: tags in common with the book that were changed BUT it had a different 'case', and Calibre updates the case of the tag or it was one of those with dozens of tags with the wrong case, so lots of books got hit FWIW I use Title case for my tags and I wish Calibre would have a 'filter action' to do that one (it has Upper, Lower, Capitalize)

11-09-2018, 11:22 AM	#4
Pierre-Olivier Enthusiast Posts: 47 Karma: 30 Join Date: Jan 2010 Location: Dans les Landes ... Device: PocketBook Touch Lux 3	Thanks for the answer, but it's not this. I only use 19 tags, and never modified them.

11-09-2018, 12:20 PM	#6
Pierre-Olivier Enthusiast Posts: 47 Karma: 30 Join Date: Jan 2010 Location: Dans les Landes ... Device: PocketBook Touch Lux 3	Of course I import regularly some eBooks. How is it possible to avoid such global modifications.?

11-09-2018, 12:33 PM	#8
DaltonST Deviser Posts: 2,265 Karma: 2090983 Join Date: Aug 2013 Location: Texas Device: none	You can change the Last Modified Date to anything you please with the Job Spy plugin.

11-09-2018, 06:15 PM	#9
davidfor Grand Sorcerer Posts: 24,907 Karma: 47303748 Join Date: Jul 2011 Location: Sydney, Australia Device: Kobo:Touch,Glo, AuraH2O, GloHD,AuraONE, ClaraHD, Libra H2O; tolinoepos	Another reason for the timestamp to be changed for all books is changing custom columns. Adding or removing them will update them all. Also, changes the set of values for a "Text, but with a fixed set of permitted values" will also update everything. That's a behaviour I really don't like. But, it's easy to fix if you want to run from source.

11-09-2018, 06:41 PM	#10
BetterRed null operator (he/him) Posts: 20,565 Karma: 26954694 Join Date: Mar 2012 Location: Sydney Australia Device: none	For all the reasons given by other responders I ignore the Modified column entirely. I have a Last Action Date custom column that I update whenever I do anything that I regard as significant. Because I edit in the book list it's easy to maintain. BR

11-11-2018, 01:25 PM	#11
Pierre-Olivier Enthusiast Posts: 47 Karma: 30 Join Date: Jan 2010 Location: Dans les Landes ... Device: PocketBook Touch Lux 3	yen I've also thought to such a solution, but Calibre Companion use only the "last_modified" column, and it's really a pain when this app decide to download metadata of thousands of eBooks because this column has been modified for an unknown reason. None of the explanation mentioned above can explain such a behavior for my use.

11-11-2018, 02:42 PM	#12
DaltonST Deviser Posts: 2,265 Karma: 2090983 Join Date: Aug 2013 Location: Texas Device: none	Going forward, back up the LMD for every book en masse routinely so it can be restored in seconds so that CC does not trigger any activity. Job Spy has 56 tools; this is one of them.