piggyback split queries

[DickBaker]

Docpage states "Each query currently implies an additional network roundtrip to your database." but surely this ain't necessarily so ? I supposethat current EF would batch the 1st & 2nd (i.e. split) query into a single TSQL request payload, so achieves a single round-trip [i.e. not needing MARS to multiplex the session, and EF also receives & digests both resultsets from a single tx from MSSQL/etc]

Document details

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• ID: 43baa9f3-c415-c328-6c10-53aabaaec652
• Version Independent ID: 4e789a1b-aa88-d194-dc2e-0a23251250d7
• Content: Single vs. Split Queries - EF Core
• Content Source: entity-framework/core/querying/single-split-queries.md
• Product: entity-framework
• Technology: entity-framework-core
• GitHub Login: @smitpatel
• Microsoft Alias: avickers

[roji]

Duplicate of dotnet/efcore#10878

[roji]

Note that you still need MARS if you don't want to buffer the first resultset - that's orthogonal to batching.

[DickBaker]

agreed "In some scenarios", but my beef was the docs emphatically state "implies an additional network roundtrip" which I think is outdated by your modern EF smarts. Again, leave in your capable hands to do/not & close. Thanks.

[DickBaker]

Earlier I had raised another Issue about split queries, but can't find the Issue in my "Participating" filter [can't see how to show Closed, so maybe I never pushed the Submit button]. Anyway I am re-submitting Issue against that page, so please don't be cross if it dupes!

[DickBaker]

please ignore the "Earlier I had .." comment as #4044 eventually surfaced (so I erased the #4046 dup)

[roji]

No problem (and definitely not cross).

but my beef was the docs emphatically state "implies an additional network roundtrip" which I think is outdated by your modern EF smarts

What makes you think this? As far as I'm aware, split queries currently always sends the 2nd query as a separate roundtrip (assuming the 2nd query is sent at all). This is definitely something I'd like us to improve (that's dotnet/efcore#10878), but that's how it is today.

[DickBaker]

oddly enough I still cannot see #4044 if I use either of these URLs
https://github.com/notifications?query=reason%3Aparticipating
https://github.com/notifications
but it shows up if I do the full
https://github.com/dotnet/EntityFramework.Docs/issues/

so I question the voracity of the filtering mechanism [unless issues are deliberately placed in a pending tray until one of you experts permits it to be moderated-in]. hmm!

[DickBaker]

I thought I had read/seen one of the EF team introduce the batching of those 2 partial queries into a single trip, but I can't pinpoint it [maybe I just dreamed it?!] or it was a 3rd-party extension. Never mind, I bow to your superior knowledge and I certainly haven't profiled it to justify my claim. I simply thought the docs were outdated and were not crediting more recent EF smarts. But what do I know?!

[roji]

@DickBaker it's pretty to test this out: you can just turn on logging and see whether there are two database commands or just one. It's a great way to play around with EF and see exactly what SQL it's generating and how it's executing it (e.g. when batching is in use).

Anyway, I'll go ahead and close this as a duplicate of dotnet/efcore#10878.