Using pg_buffercache_summary() is significantly cheaper than querying pg_buffercache and summarizing in SQL. Author: Melih Mutlu <m.melihmutlu@gmail.com> Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: Aleksander Alekseev <aleksander@timescale.com> Reviewed-by: Zhang Mingli <zmlpostgres@gmail.com> Discussion: https://postgr.es/m/CAGPVpCQAXYo54Q%3D8gqBsS%3Du0uk9qhnnq4%2B710BtUhUisX1XGEg%40mail.gmail.com
There are still some alignment-related failures in the buildfarm, which might or might not be able to be fixed quickly, but I've also just realized that it increased the size of many WAL records by 4 bytes because a block reference contains a RelFileLocator. The effect of that hasn't been studied or discussed, so revert for now.
RelFileNumbers are now assigned using a separate counter, instead of being assigned from the OID counter. This counter never wraps around: if all 2^56 possible RelFileNumbers are used, an internal error occurs. As the cluster is limited to 2^64 total bytes of WAL, this limitation should not cause a problem in practice. If the counter were 64 bits wide rather than 56 bits wide, we would need to increase the width of the BufferTag, which might adversely impact buffer lookup performance. Also, this lets us use bigint for pg_class.relfilenode and other places where these values are exposed at the SQL level without worrying about overflow. This should remove the need to keep "tombstone" files around until the next checkpoint when relations are removed. We do that to keep RelFileNumbers from being recycled, but now that won't happen anyway. However, this patch doesn't actually change anything in this area; it just makes it possible for a future patch to do so. Dilip Kumar, based on an idea from Andres Freund, who also reviewed some earlier versions of the patch. Further review and some wordsmithing by me. Also reviewed at various points by Ashutosh Sharma, Vignesh C, Amul Sul, Álvaro Herrera, and Tom Lane. Discussion: http://postgr.es/m/CA+Tgmobp7+7kmi4gkq7Y+4AM9fTvL+O1oQ4-5gFTT+6Ng-dQ=g@mail.gmail.com
We can't check the output of this view very closely without creating portability headaches, but we can make sure that the number of rows is as-expected. In any case, this is sufficient to exercise all the C code within, which is a lot better than the 0% coverage we had before. DongWook Lee Discussion: https://postgr.es/m/CAAcByaLCHGJB7qAENEcx9D09UL=w4ma+yijwF_-1MSqQZ9wK6Q@mail.gmail.com
Andres Freund pointed out that allowing non-superusers to run "CREATE EXTENSION ... FROM unpackaged" has security risks, since the unpackaged-to-1.0 scripts don't try to verify that the existing objects they're modifying are what they expect. Just attaching such objects to an extension doesn't seem too dangerous, but some of them do more than that. We could have resolved this, perhaps, by still requiring superuser privilege to use the FROM option. However, it's fair to ask just what we're accomplishing by continuing to lug the unpackaged-to-1.0 scripts forward. None of them have received any real testing since 9.1 days, so they may not even work anymore (even assuming that one could still load the previous "loose" object definitions into a v13 database). And an installation that's trying to go from pre-9.1 to v13 or later in one jump is going to have worse compatibility problems than whether there's a trivial way to convert their contrib modules into extension style. Hence, let's just drop both those scripts and the core-code support for "CREATE EXTENSION ... FROM". Discussion: https://postgr.es/m/20200213233015.r6rnubcvl4egdh5r@alap3.anarazel.de
When maintaining or merging patches, one of the most common sources for conflicts are the list of objects in makefiles. Especially when the split across lines has been changed on both sides, which is somewhat common due to attempting to stay below 80 columns, those conflicts are unnecessarily laborious to resolve. By splitting, and alphabetically sorting, OBJS style lines into one object per line, conflicts should be less frequent, and easier to resolve when they still occur. Author: Andres Freund Discussion: https://postgr.es/m/20191029200901.vww4idgcxv74cwes@alap3.anarazel.de
Three nologin roles with non-overlapping privs are created by default * pg_read_all_settings - read all GUCs. * pg_read_all_stats - pg_stat_*, pg_database_size(), pg_tablespace_size() * pg_stat_scan_tables - may lock/scan tables Top level role - pg_monitor includes all of the above by default, plus others Author: Dave Page Reviewed-by: Stephen Frost, Robert Haas, Peter Eisentraut, Simon Riggs
The pg_buffercache_pages function provided by this extension is PARALLEL SAFE. Andreas Karlsson
The new column shows how many backends have a buffer pinned. That can be useful during development or to diagnose production issues e.g. caused by vacuum waiting for cleanup locks. To handle upgrades transparently - the extension might be used in views - deal with callers expecting the old number of columns. Reviewed by Fujii Masao and Rajeev rastogi.
Prominent binaries already had this metadata. A handful of minor binaries, such as pg_regress.exe, still lack it; efforts to eliminate such exceptions are welcome. Michael Paquier, reviewed by MauMau.