The only justification for the synonym I could find was in the answer to Why is "query" a suggested synonym for "sql"?:
Simply because when the site was young, we repeatedly had folks posting questions about "query" when they really meant "help me with my sql" and don't understand the esoteric differences of the ...
No they are not synonymous.
An UPSERT can be implemented without using the MERGE keyword and conversely UPSERT is just one possible use case for MERGE (when it has both a WHEN MATCHED THEN UPDATE and WHEN NOT MATCHED [ BY TARGET ] THEN INSERT ...)
At least in SQL Server it is not required that MERGE have both (or indeed either) of these clauses.
Yes, crosstab should be a synonym of pivot and merged.
Any product-specific differences are indicated by the product tag.
A synonym has been created.
crosstab has been removed from 9 questions.
pivot has been added to 4 questions.
Tag merge completed.
Originally, unique-key was set as the master for unique-constraint and unique-index because it was by far the more popular tag, and the only one with any usage guidance.
There may be semantic differences, but it did seem like the tagged questions were all asking about essentially the same thing. To put it another way, the master tag was enough to help ...
log is a useless tag (as is logs), but looking at the questions it does not seem to be safe simply to make this a synonym of transaction-log.
A good number (perhaps most) of the questions should be retagged using the following (mostly MySQL-specific) tags:
(these tags also need usage guidance).
For example (just from ...
set-returning-functions is no longer a synonym of functions.
table-valued-functions is no longer a synonym of functions
table-valued-functions is now a synonym of set-returning-functions as requested.
No tag assignments were lost.
We can monitor the usage of these tags and revisit the situation after a period of time.
Some might prefer the master tag to be named identity-property (as in SQL Standard feature F384 "Drop identity property clause") with the following synonyms:
...so I am providing this as an answer option.
For example, in SQL Server identity is referred to as a property of a column.
It seems relational ought to be a synonym of relational-theory and then merged. I'll wait to see what the community response is to this idea before taking any action.
Update: the synonym has been created and a merge performed.
The rdbms tag issue is addressed in a separate meta discussion.
It has been over a month and no one has answered so I'm adding my own answer.
I think the tag rdbms should be removed and replaced.
I think the tag relational should be just removed, because I don't understand where/how it really adds value.
I think the tag relational-theory should stay.
I disagree on removing pgadmin tag / renaming to pgadmin-3 - but not strongly on adding it to old questions that apply.
With only 160 questions tagged pgadmin, I don't see any benefit on renaming.
PgAdmin 4 is a total rewrite.
PgAdmin 4 is a total rewrite, yes. But do we really care if the program is written in C or Python? The functionality is very ...
While I don't love it either, I do think that the functions tag works best as a broad tag.
As Evan alluded to, there are a ton of more specific versions (far more than the 4 listed) that could exist, but I think that it would be more confusing than helpful for many askers and most of them wouldn't get a lot of use.
So, I propose an alternative: built-in-...