On Fri, Feb 3, 2023 at 5:48 PM veem v <veema0...@gmail.com> wrote: > Actually I did the testing by connecting to "https://dbfiddle.uk/"; > postgres version -15. > > PostgreSQL 15.0 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 8.5.0 > 20210514 (Red Hat 8.5.0-10), 64-bit > > Am I doing it wrong, please confirm? > > No clue. But even SQLite can generate 1M uuid (16 bytes random blobs are equivalent) is 1/3 of the time, so 30x faster. So your timings of generating 100K uuids and counting them seems way too slow to me. --DD
sqlite> select count(randomblob(16)) from generate_series(1,1000*1000); QUERY PLAN `--SCAN generate_series VIRTUAL TABLE INDEX 3: addr opcode p1 p2 p3 p4 p5 comment ---- ------------- ---- ---- ---- ------------- -- ------------- 0 Init 0 15 0 0 Start at 15 1 Null 0 1 1 0 r[1..1]=NULL 2 VOpen 0 0 0 vtab:274D3E0 0 3 Integer 1 4 0 0 r[4]=1 4 Multiply 6 6 5 0 r[5]=r[6]*r[6] 5 Integer 3 2 0 0 r[2]=3 6 Integer 2 3 0 0 r[3]=2 7 VFilter 0 11 2 0 iplan=r[2] zplan='' 8 Function 1 8 7 randomblob(1) 0 r[7]=func(r[8]) 9 AggStep 0 7 1 count(1) 1 accum=r[1] step(r[7]) 10 VNext 0 8 0 0 11 AggFinal 1 1 0 count(1) 0 accum=r[1] N=1 12 Copy 1 9 0 0 r[9]=r[1] 13 ResultRow 9 1 0 0 output=r[9] 14 Halt 0 0 0 0 15 Transaction 0 0 1 0 1 usesStmtJournal=0 16 Integer 1000 6 0 0 r[6]=1000 17 Integer 16 8 0 0 r[8]=16 18 Goto 0 1 0 0 ┌───────────────────────┐ │ count(randomblob(16)) │ ├───────────────────────┤ │ 1000000 │ └───────────────────────┘ Run Time: real 0.278 user 0.250000 sys 0.000000 > On Fri, 3 Feb 2023 at 21:28, Dominique Devienne <ddevie...@gmail.com> > wrote: > >> Something's off regarding Guid generations IMHO... >> You generate 100K Guids in ~1s. While we generate (in C++, Windows >> Release, using Boost) 16M of them in +/- the same time: >> >
