On Wed, Sep 07, 2022 at 10:48:39AM +0200, Drouvot, Bertrand wrote: > Hi, > > On 6/22/22 4:38 PM, Justin Pryzby wrote: > > ATRewriteTable() calls table_tuple_insert() with a bistate, to avoid clobbering > > and polluting the buffers. > > > > But heap_insert() then calls > > heap_prepare_insert() > > > heap_toast_insert_or_update > > > toast_tuple_externalize > > > toast_save_datum > > > heap_insert(toastrel, toasttup, mycid, options, NULL /* without bistate:( */); > > What do you think about creating earlier a new dedicated bistate for the > toast table?
Yes, but I needed to think about what data structure to put it in...
Here, I created a 2nd bistate for toast whenever creating a bistate for heap. That avoids the need to add arguments to tableam's table_tuple_insert(), in addition to the 6 other functions in the call stack.
I also updated rewriteheap.c to handle the same problem in CLUSTER:
postgres=# DROP TABLE t; CREATE TABLE t AS SELECT i, repeat((5555555+i)::text, 123456)t FROM generate_series(1,9999)i; postgres=# VACUUM FULL VERBOSE t ; SELECT COUNT(1), datname, coalesce(c.relname,b.relfilenode::text), d.relname FROM pg_buffercache b LEFT JOIN pg_class c ON b.relfilenode=pg_relation_filenode(c.oid) LEFT JOIN pg_class d ON d.reltoastrelid=c.oid LEFT JOIN pg_database db ON db.oid=b.reldatabase GROUP BY 2,3,4 ORDER BY 1 DESC LIMIT 22;
Unpatched: 5000 | postgres | pg_toast_96188840 | t => 40MB of shared buffers
Patched: 2048 | postgres | pg_toast_17097 | t
Note that a similar problem seems to exist in COPY ... but I can't see how to fix that one.
