Re: Super-smack?

Isn't Super Smack a breakfast cereal? :-)

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Tom Lane wrote:
> I wrote:
> > FWIW, my own experiments with tests like this suggest that PG is at
> > worst about 2x slower than mysql for trivial queries. If you'd reported
> > a result in that ballpark I'd have accepted it as probably real. 6x I
> > don't believe though ...
>
> Just for amusement's sake, I tried compiling up super-smack on my own
> machine, and got results roughly in line with what I would've expected.
>
> Machine: dual Xeon EM64T, forget the clock rate at the moment, running
> Fedora Core 4 (kernel 2.6.15-1.1831_FC4smp); hyperthreading enabled
>
> Postgres: fairly recent CVS tip, no special build options except
> --enable-debug, no changes to default runtime configuration options
>
> MySQL: 5.0.18, current Red Hat RPMs, no changes to default configuration
>
> The "select" test, with 1 and 10 clients:
>
> $ super-smack -d pg select-key.smack 1 10000
> Query Barrel Report for client smacker1
> connect: max=0ms min=-1ms avg= 3ms from 1 clients
> Query_type num_queries max_time min_time q_per_s
> select_index 20000 0 0 3655.24
> $ super-smack -d pg select-key.smack 10 10000
> Query Barrel Report for client smacker1
> connect: max=54ms min=4ms avg= 12ms from 10 clients
> Query_type num_queries max_time min_time q_per_s
> select_index 200000 0 0 7431.20
>
> $ super-smack -d mysql select-key.smack 1 10000
> Query Barrel Report for client smacker1
> connect: max=0ms min=-1ms avg= 0ms from 1 clients
> Query_type num_queries max_time min_time q_per_s
> select_index 20000 0 0 6894.03
> $ super-smack -d mysql select-key.smack 10 10000
> Query Barrel Report for client smacker1
> connect: max=14ms min=0ms avg= 5ms from 10 clients
> Query_type num_queries max_time min_time q_per_s
> select_index 200000 0 0 16798.05
>
> The "update" test, with 1 and 10 clients:
>
> $ super-smack -d pg update-select.smack 1 10000
> Query Barrel Report for client smacker
> connect: max=0ms min=-1ms avg= 4ms from 1 clients
> Query_type num_queries max_time min_time q_per_s
> select_index 10000 0 0 1027.49
> update_index 10000 0 0 1027.49
> $ super-smack -d pg update-select.smack 10 10000
> Query Barrel Report for client smacker
> connect: max=13ms min=5ms avg= 8ms from 10 clients
> Query_type num_queries max_time min_time q_per_s
> select_index 100000 1 0 1020.96
> update_index 100000 28 0 1020.96
>
> The above is with fsync on (though I think this machine's disk lies
> about write complete so I'd not trust it as production). With fsync off,
>
> $ super-smack -d pg update-select.smack 1 10000
> Query Barrel Report for client smacker
> connect: max=0ms min=-1ms avg= 3ms from 1 clients
> Query_type num_queries max_time min_time q_per_s
> select_index 10000 0 0 1478.25
> update_index 10000 0 0 1478.25
> $ super-smack -d pg update-select.smack 10 10000
> Query Barrel Report for client smacker
> connect: max=35ms min=5ms avg= 21ms from 10 clients
> Query_type num_queries max_time min_time q_per_s
> select_index 100000 1 0 3067.68
> update_index 100000 1 0 3067.68
>
> versus mysql
>
> $ super-smack -d mysql update-select.smack 1 10000
> Query Barrel Report for client smacker
> connect: max=0ms min=-1ms avg= 0ms from 1 clients
> Query_type num_queries max_time min_time q_per_s
> select_index 10000 0 0 4101.43
> update_index 10000 0 0 4101.43
> $ super-smack -d mysql update-select.smack 10 10000
> Query Barrel Report for client smacker
> connect: max=3ms min=0ms avg= 0ms from 10 clients
> Query_type num_queries max_time min_time q_per_s
> select_index 100000 1 0 5388.31
> update_index 100000 6 0 5388.31
>
> Since mysql is using myisam tables (ie not transaction safe), I think
> the fairest comparison is to the fsync-off numbers.
>
> regards, tom lane
>
> ---------------------------(end of broadcast)---------------------------
> TIP 9: In versions below 8.0, the planner will ignore your desire to
> choose an index scan if your joining column's datatypes do not
> match
>

--
Bruce Momjian http://candle.pha.pa.us
EnterpriseDB http://www.enterprisedb.com

+ If your life is a hard drive, Christ can be your backup. +