Location via proxy:   [ UP ]  
[Report a bug]   [Manage cookies]                
Skip to content
Permalink

Comparing changes

Choose two branches to see what’s changed or to start a new pull request. If you need to, you can also or learn more about diff comparisons.

Open a pull request

Create a new pull request by comparing changes across two branches. If you need to, you can also . Learn more about diff comparisons here.
base repository: postgresql-cfbot/postgresql
Failed to load repositories. Confirm that selected base ref is valid, then try again.
Loading
base: cf/5542~1
Choose a base ref
...
head repository: postgresql-cfbot/postgresql
Failed to load repositories. Confirm that selected head ref is valid, then try again.
Loading
compare: cf/5542
Choose a head ref
  • 6 commits
  • 28 files changed
  • 4 contributors

Commits on May 13, 2025

  1. IOS/TableAM: Support AM-specific fast visibility tests 

    Previously, we assumed VM_ALL_VISIBLE is universal across all AMs. This
is probably not the case, so we introduce a new table method called
"table_index_vischeck_tuples" which allows anyone to ask the AM whether
a tuple is definitely visible to everyone or might be invisible to
someone.

The API is intended to replace direct calls to VM_ALL_VISIBLE and as such
doesn't include "definitely dead to everyone", as the Heap AM's VM doesn't
support *definitely dead* as output for its lookups; and thus it would be
too expensive for the Heap AM to produce such results.

A future commit will use this inside GIST and SP-GIST to fix a race
condition between IOS and VACUUM, which causes a bug with tuple
visibility, and a further patch will add support for this to nbtree.
    @MMeent
    MMeent authored and Commitfest Bot committed May 13, 2025
    Configuration menu
    Copy the full SHA
    055b990 View commit details
    Browse the repository at this point in the history

  2. GIST: Fix visibility issues in IOS 

    Previously, GIST IOS could buffer tuples from pages while VACUUM came
along and cleaned up an ALL_DEAD tuple, marking the tuple's page
ALL_VISIBLE again and making IOS mistakenly believe the tuple is indeed
visible.

With this patch, pins now conflict with GIST vacuum, and we now do
preliminary visibility checks to be used by IOS so that the IOS
infrastructure knows to recheck the heap page even if that page is now
ALL_VISIBLE.

Idea from Heikki Linnakangas
    @MMeent
    MMeent authored and Commitfest Bot committed May 13, 2025
    Configuration menu
    Copy the full SHA
    1749f1c View commit details
    Browse the repository at this point in the history

  3. SP-GIST: Fix visibility issues in IOS 

    Previously, SP-GIST IOS could buffer tuples from pages while VACUUM came
along and cleaned up an ALL_DEAD tuple, marking the tuple's page
ALL_VISIBLE again and making IOS mistakenly believe the tuple is indeed
visible.

With this patch, pins now conflict with SP-GIST vacuum, and we now do
preliminary visibility checks to be used by IOS so that the IOS
infrastructure knows to recheck the heap page even if that page is now
ALL_VISIBLE.

Idea from Heikki Linnakangas
    @MMeent
    MMeent authored and Commitfest Bot committed May 13, 2025
    Configuration menu
    Copy the full SHA
    cf116aa View commit details
    Browse the repository at this point in the history

  4. NBTree: Reduce Index-Only Scan pin duration 

    Previously, we would keep a pin on every leaf page while we were returning
tuples to the scan.  With this patch, we utilize the newly introduced
table_index_vischeck_tuples API to pre-check visibility of all TIDs, and
thus unpin the page well ahead of when we'd usually be ready with returning
and processing all index tuple results.  This reduces the time VACUUM may
have to wait for a pin, and can increase performance with reduced redundant
VM checks.
    @MMeent
    MMeent authored and Commitfest Bot committed May 13, 2025
    Configuration menu
    Copy the full SHA
    7e0272c View commit details
    Browse the repository at this point in the history

  5. Test for IOS/Vacuum race conditions in index AMs 

    Add regression tests that demonstrate wrong results can occur with index-only
scans in GiST and SP-GiST indexes when encountering tuples being removed by a
concurrent VACUUM operation.

With these tests the index AMs are also expected to not block VACUUM even when
they're used inside a cursor.

Co-authored-by: Matthias van de Meent <boekewurm+postgres@gmail.com>
Co-authored-by: Peter Geoghegan <pg@bowt.ie>
Co-authored-by: Michail Nikolaev <michail.nikolaev@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/CANtu0oi0rkR%2BFsgyLXnGZ-uW2950-urApAWLhy-%2BV1WJD%3D_ZXA%40mail.gmail.com
    @MMeent @petergeoghegan
    3 people authored and Commitfest Bot committed May 13, 2025
    Configuration menu
    Copy the full SHA
    b798aa8 View commit details
    Browse the repository at this point in the history

  6. [CF 5542] v12 - Fix buffer pinning logic in [SP-]Gist 

    This branch was automatically generated by a robot using patches from an
email thread registered at:

https://commitfest.postgresql.org/patch/5542

The branch will be overwritten each time a new patch version is posted to
the thread, and also periodically to check for bitrot caused by changes
on the master branch.

Patch(es): https://www.postgresql.org/message-id/CAEze2WgnHJF66BtviDFNCPy26gLrb+tfns-Bi62DBfReH0-UCg@mail.gmail.com
Author(s): Peter Geoghegan, Michail Nikolaev, Matthias van de Meent, Mihail Nikalayeu
    Commitfest Bot committed May 13, 2025
    Configuration menu
    Copy the full SHA
    539e92e View commit details
    Browse the repository at this point in the history
Loading