New patches and a rebase.
0001 - no changes, but the longer I go the more I'm certain this is something we want to do.
0002- same as 0001
0003 -
Storing the restore function calls in the archive entry hogged a lot of memory and made people nervous. This introduces a new function pointer that generates those restore SQL calls right before they're written to disk, thus reducing the memory load from "stats for every object to be dumped" to just one object. Thanks to Nathan for diagnosing some weird quirks with various formats.
0004 -
This replaces the query in the prepared statement with one that batches them 100 relations at a time, and then maintains that result set until it is consumed. It seems to have obvious speedups.
database pg14, 100k tables x 2 columns each:
0004: 34.5s with statistics, 25.04s without
0003: 42.23s with statistics, 24.29s without
0002: 42.25s with statistics, 23.17s without
Gory details:
PGSERVICE=benchmark14 time /usr/local/pgsql/bin/pg_dump --file=tip.run1.dump
5.45user 2.38system 0:34.50elapsed 22%CPU (0avgtext+0avgdata 912680maxresident)k
0inputs+2105736outputs (0major+245090minor)pagefaults 0swaps
PGSERVICE=benchmark14 time /usr/local/pgsql/bin/pg_dump --no-statistics --file=tip.nostats.run1.dump
4.36user 2.05system 0:25.04elapsed 25%CPU (0avgtext+0avgdata 702488maxresident)k
0inputs+1643048outputs (0major+192512minor)pagefaults 0swaps
PGSERVICE=benchmark14 time /usr/local/pgsql/bin/pg_dump --file=nobatch.run1.dump
5.60user 3.95system 0:42.23elapsed 22%CPU (0avgtext+0avgdata 902424maxresident)k
0inputs+2105672outputs (0major+242536minor)pagefaults 0swaps
PGSERVICE=benchmark14 time /usr/local/pgsql/bin/pg_dump --no-statistics --file=nobatch-nostats.run1.dump
4.38user 2.13system 0:24.29elapsed 26%CPU (0avgtext+0avgdata 702292maxresident)k
48inputs+1642952outputs (0major+192515minor)pagefaults 0swaps
PGSERVICE=benchmark14 time /usr/local/pgsql/bin/pg_dump --file=nostmtfn.run1.dump
6.01user 4.47system 0:42.25elapsed 24%CPU (0avgtext+0avgdata 1089784maxresident)k
0inputs+2106840outputs (0major+289407minor)pagefaults 0swaps
PGSERVICE=benchmark14 time /usr/local/pgsql/bin/pg_dump --no-statistics --file=nostmtfn-nostats.run1.dump
4.35user 2.13system 0:23.17elapsed 27%CPU (0avgtext+0avgdata 690000maxresident)k
0inputs+1642952outputs (0major+189383minor)pagefaults 0swaps
