I was diving in my Wordpress installation to start thinking in a future development and I did this query:
select * from postmeta where post_id = 1485433 and meta_key = 'qode_revolution-slider'
This query has as result 6 rows... identical, except for the meta_id value.
In fact, for test, I executed:
select post_id, meta_key, count(meta_id) as metas from tpostmeta where post_id > 0 group by post_id, meta_key having metas > 1 order by post_id;
And I have several posts (more than 30) whit the same meta_key more than once... I have seen 2, 3, 6 and 8 times repeated some values...
Is it normal? I thought that each combination post_id/meta_key must be unique, and this was a wordpress core job..
Thanks you all, regards