03.03.2016 16:51, Dimitry Sibiryakov wrote: > 03.03.2016 15:07, Vlad Khorsun wrote: >>> I wouldn't expect much from lock manager, but hash joins can get >>> significant boost, >>>> especially on long keys. >> You don't need "server with dozen of cores" to check it, isn't is ? > > You are right, this part I can test even with my notebook. But will you > believe my > numbers?..
Why not ? > Here they are: > >> SQL> show version; >> ISQL Version: WI-V3.0.0.32342 Firebird 3.0 Release Candidate 2 >> Server version: >> Firebird/Windows/Intel/i386 (access method), version "WI-V3.0.0.32342 >> Firebird 3.0 Release Candidate 2" >> on disk structure version 12.0 >> SQL> select count(*) from t1 join t2 on t1.a=t2.a; >> >> PLAN HASH (T2 NATURAL, T1 NATURAL) >> >> COUNT >> ===================== >> 32 >> >> Current memory = 342822008 >> Delta memory = 0 >> Max memory = 342998536 >> Elapsed time= 1.775 sec >> Buffers = 40000 >> Reads = 0 >> Writes = 0 >> Fetches = 218290 >> >> SQL> show version; >> ISQL Version: WI-T4.0.0.32373 Firebird 4.0 Unstable >> Server version: >> Firebird/Windows/AMD/Intel/x64 (access method), version "WI-T4.0.0.32373 >> Firebird 4.0 Unstable" >> on disk structure version 12.0 >> SQL> select count(*) from t1 join t2 on t1.a=t2.a; >> >> PLAN HASH (T2 NATURAL, T1 NATURAL) >> >> COUNT >> ===================== >> 32 >> >> Current memory = 354135072 >> Delta memory = 0 >> Max memory = 354316480 >> Elapsed time= 0.924 sec >> Buffers = 40000 >> Reads = 0 >> Writes = 0 >> Fetches = 218290 Looks nice, but you "forget" to show table's DDL and how data was generated. I guess you have join on long strings. It is ok as special case, but very far from real life, i'm afraid. Vlad PS I'm not against you or your code, i'm against your public behavior. PPS Don't forget to test without first two if's :) ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140 Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
