Hello,

This is an important information regarding our database, for people running tools and scripts.

*The change*

In the wb_terms table, a new column term_full_entity_id containing strings with the full ID including the letter (ie. “Q42”) will be created, and will be used instead of the current column term_entity_id that only stores the numeric part of the ID (ie. “42”).

This change is made, among other things, to support the new entity types to come, and then to store terms of entities that have non-numeric IDs, for example Forms (“L42-F1”).

*Implications*

- This change only affects tools that directly access the database. Other tools, for example those getting data through the API, pywikibot, gadgets, etc. will not be affected and will work as before with no action required from the maintainers. - in order to adapt tools to the new database structure, database queries using wb_terms should be changed so that they use term_full_entity_id column instead of term_entity_id. This might potentially simplify queries. For example, instead of having a condition WHERE term_entity_type='item' AND term_entity_id=42, one could now do: WHERE term_full_entity_id='Q42'. - term_entity_type is not affected by this change, and will still be available as before.

*The process*

Starting now, we will work through several steps to achieve this change. Note that the dates indicated below may not be exact. We will announce each of the steps separately. Here is a rough timeline:

- June 22th: the new column, term_full_entity_id, becomes visible on Labs. It will be fully populated in the testwikidatawiki database replica on Labs. Note that this column will remain incomplete in the wikidatawiki database until later! Tools that use the wb_terms table can test new code that uses the new term_full_entity_id column with the testwikidatawiki database, but must keep using the old code with the wikidatawiki database. - Some time later: testwikidatawiki should be fully populated, and become usable on the wikidatawiki database. Tools that use the wb_terms table can now switch to using new code that no longer uses the old term_entity_id column on all databases. - Eventually (not before July 6th): the old term_entity_id column is removed from the testwikidatawiki and wikidatawiki database replicas on labs. Any code that still uses the old term_entity_id will break.

If you have any question or problem regarding this change, feel free to answer to this mail or write directly to me.