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Topic: Deletion of Dictionary Lists

The NHM are proposing to delete a number of obsolete Dictionary Lists.  Where the Taxon_List_Item keys which make up a deleted list have been used on records in R6 they will be re-allocated  to Taxon_List_Item keys in the new Master list. The Taxon_Version_Key will remain unchanged, so  the species allocated will remain the same.  In order to ensure that no information is lost the name of the Original List used will be added to Taxon_Private_Data.

The list which are to be deleted are not generally used for input, so we anticipate that their deletion will have minimal impact of R6 system. Initially the proposal is to remove the following lists.   

List of Additional Names  -  No further additions or changes will be made to this list. It is poorly structured and taking  along time to open. New taxa will go into a new Master List which will be structured. 

Passmore Edwards - this list has rarely been used by R6 users. It has no structure and takes minutes to open.         

Forestry Commission list - This list has only been partly implemented in R6

If you have any question about this proposed change or would like further information please reply here.

Mike Weideli
Littlefield Consultancy - IT Consultants

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Re: Deletion of Dictionary Lists

Mike, you say that those proposed for deletion are generally not used for input - however the List of Additional Names has been used extensively in the past and was (?) created so records could be entered quickly. I believe the idea of this list was a temporary measure with taxa being moved to the appropriate place, but in reality has this happened?

I'm all in favour in tidying up the taxonomic hierarchy / lists*, but is deleting lists the right way to go about it? What problem are the lists causing that deleting them solves? I'm very wary of automatically re-allocating keys and would prefer to run a report to pull out any records we have entered against these lists and manually change them, if deletion goes ahead.

The use of lists provides (in a bad way through no fault) provenance to a name and just because a list is rarely used doesn't mean that that provenance isn't important. I don't think adding the list name to the taxon_private_data field would be enough to maintain this because if the list is deleted you can't then look it up.

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*I would like to completely remove the idea of lists and just have a single hierarchy that provides the ability to enter the name as recorded

Charlie Barnes
Information Officer
Greater Lincolnshire Nature Partnership

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Re: Deletion of Dictionary Lists

Hi

Thank you for your comments. The reason for asking was to see what users thought before any action is taken.   

The problem that we are facing is that the Taxon List item table is growing rapidly now with 730,000 entries for just 319,000 taxon names (ie with junior synonyms)  and only 120,000 taxa. My fear is some point the size of this and the associated index tables will impact on R6 performance.   

The NHM will no longer be maintaining the majority of Lists as there is no demand from the list providers.  This means that most lists will never be updated.  Certainly, the list of additional names will no longer be added to or updated in any way. Entries which would have gone in there will be in the new Master List.  It seems reasonable to delete the List of Additional  Names as I can't see what is to be gained by keeping it.  Passmore Edwards is a badly constructed list full of anomalies and errors, so this seems reasonable candidate to go and the Forestry Commission List is not complete in R6 with only a few entries. If a TLI key is deleted it will always be reallocated to the Master list and it would always retain the Taxon Version Key, so it would retain the name as recorded.             

I totally agree with your last point and technically this can be achieved right now, just by adding the junior synonyms to the Master List, but this means adding about 200,000 Taxon_List_Item keys. I fear this might cause serious performance problems. 
   
I think it will be worth testing the effect of adding the 200,000 junior synonyms. This would at least indicate if we are close to encountering problems.   

Mike

Mike Weideli
Littlefield Consultancy - IT Consultants

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Re: Deletion of Dictionary Lists

Ah, so you're not actually talking about contents of the list, rather the name of the list? I think I must have missed your second sentence which alluded to that. If it were me I'd go for seeing the effect of adding 200,000 synonyms if its not too much trouble.

Out of curiosity, is there a particular bottleneck in Recorder that's giving concern? Certainly SQL server should be able to cope.

Charlie Barnes
Information Officer
Greater Lincolnshire Nature Partnership

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Re: Deletion of Dictionary Lists

Hi

I have tried adding all the junior synonyms the new Master list as a test and it all works fine on my machines,  Chris Raper would be willing to implement it for the benefit of R6 users. I have also spoken with John van-Breda and thinks it a good idea and that R6 should be able to handle the additional taxon List Item keys.  However, he does think that this is a change  which we should consult the Steering Group about so it isn't something I can take forward  at present.  For the moment the new Master  list  will contain the recommended  taxon version keys and just those junior synonyms  arising from  changes. This will still be a useful list as in effect it will be a current UKSI  list.  The List of additional Names will no longer be maintained and any new taxa will go into the Master List.

Mike Weideli
Littlefield Consultancy - IT Consultants

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Re: Deletion of Dictionary Lists

Thanks Mike - that's good news. Given the current situation, probably no need to rush!

Charlie Barnes
Information Officer
Greater Lincolnshire Nature Partnership