Search isn't showing all the results I'd expect

[niquewoodhouse]

Is your suggestion related to a problem? Please describe.
Some users are reporting that, when trying to use the search, they're surprised/frustrated to find it's just searching rooms/DMs they're already a member of.
As the UI and copy makes it look like a global search, and not a filter, it would be reasonable to understand the issue.

Describe the solution you'd like
An easily accessible global search that searches more than just rooms I'm in.

Describe alternatives you've considered
Cmd + F to search for specific names. Making the explore button more obvious might help but that's not a solution to this problem, because users are not thinking they need to decide between rooms they're in and rooms they're not in at this stage.

Additional context
People's expectations may have been set by other products they use - where prominent searches are for quickly finding anything - Gmail, Github, Facebook, etc etc.

[t3chguy]

The difficulty with this in Matrix is there is no global. No one server/client knows about every server/room.

Additionally see #14617 (comment)

[bkil]

Sure, offering global search is a far cry, but I think as a compromise, it would still be useful to be able to do search local within the home server that I submit my request to. The server could most effortlessly search within its own local database of public events corresponding to public rooms that any of its users are in.

Not sure whether we have a general search enhancement issue already, but search usability itself would benefit from lots of enhancements:

• support searching (tokenizing) username and room mxid mentions and URL (or hostnames) properly - you can't search for them generally
• search for my mentions, replies & my watched keywords (i.e., "Why did this room filled with hundreds of messages ping me yesterday, who asked me something?")
• filter on sender mxid or display name
• filter by date
• filter by room (regexp?)
• display help on the search syntax - I know it was using Postgres full text search under the hood, but today I learned that it also supports negation on the interface (except for stop words...)
• also index edited posts, not only the first version of each event - this is very confusing
• cache search results on client side at least for a short duration
• provide better previewing of search results - at present it only gives +/-1 lines of context, if you click away, you have to search again and scroll to the position you were at all over again (similar problem in spirit to Ability to peek into each search result when doing a directory search via Explore Rooms #21288 )
• wishlist (probably can't be done easily): proximity search within neighboring messages - some people press enter between every sentence and submit very short messages and phrase searching within a single message is rarely useful to find such text
• incremental search: if I search for something within the given room and after scrolling through I determined that it was in a different room, clicking on search all rooms will also intermingle results of this room with other rooms (perhaps a new button to search in other rooms only?)
• provide a method to search for public attachments, like based on file type, filename, size and such